VV6500C001 ,DUAL-MODE DIGITAL CAMERA CHIPSETapplications to be written.continuous video capture is not possible.September 2001 Version 3.4 1/63 ..
VV6501C001 ,DUAL-MODE DIGITAL CAMERA CO-PROCESSORelectrical characteristics .....47Chapter 7 Optical Characteristics . . . .487.1 Optical char ..
VX-55-1A3 , Snap Action Switch
VX6953CBQ05I/1 ,5.1 megapixel EDOF camera moduleBlock diagram . . . . 173.2 Digital video block . . 183.2.1 Dark calibration algorithm ..
VY1222M47Y5UQ63V0 , Ceramic Disc Capacitors Safety Standard Approved Disc AC Capacitors
W.FL-R-SMT-1 , Ultra Small Surface Mount Coaxial Connectors - 1.4mm Mated Height
WSD411 , Surface Mount Schottky Barrier Diode
WSD411 , Surface Mount Schottky Barrier Diode
WSD520G , Surface Mount Schottky Barrier Diodes
WSD520S , Surface Mount Schottky Barrier Diodes
WSD551H , SMALL SIGNAL SCHOTTKY DIODES 500m AMPERES 30 VOLTS
WSD551H , SMALL SIGNAL SCHOTTKY DIODES 500m AMPERES 30 VOLTS
VV6410-VV6410C036-VV6411C036-VV6500C001
Mono and Colour Digital Video CMOS Image Sensors
STV0680B+ VV6410/6411/6500DUAL-MODE DIGIT AL CAMERA CHIPSET
DESCRIPTION STMicroelectronics Imaging Division has enhanced
the feature set of the STV0680B low cost dual-
mode camera chipset to allow a new line of low cost
cameras or toy products to be brought to the
market.
STANDARD FEATURESST have maintained the standard features already
available in the successful STV0680B-001 chipset,
including: STV0680B-003 fully backward compatible
with STV0680B-001 Support for VV6410/6411 (CIF) and VV6500
(VGA) CMOS imaging sensors. Support for SDRAM sizes 16MBit (up to 20
CIF images) or 64Mbit (up to 80 CIF or 26
VGA images). Low resolution “economy” mode allows for
more images to be stored. High frame rate web cam (tethered video)
over USB. Automatic anti-flicker exposure control. Image up load over RS232 or USB. Driver support for Win98/Win2k/WinME and
MacOS 8.6/9.0/9.1. Continuous capture while untethered (except
when Flashgun enabled) and downloading to
AVI file format Power-saving “stand-by” mode which
maintains memory contents, as well as
generally low power consumption. Simple user interface including 2 buttons,
status LCD display, and buzzer. Evaluation Kit (EVK) available. Software Development Kit (SDK) allows OEM
PC Software applications to be written.
NEW FEATURES AVAILABLE IN STV0680B-003 Audio record/playback and “Delete Last”
function Custom sounds playback (e.g. “Talking” or
“Musical” camera) Flashgun support Quick Power Down (by holding Mode
Button).
Audio Record And PlaybackThe enhanced features included in STV0680B-003
allow audio memos to be recorded, stored in
SDRAM, and uploaded to the PC over USB or
RS232, to be played back using an OEM software
application developed using the SDK
With the addition of playback hardware, recorded
audio sounds can also be played back on the
camera, and it is possible to download a set of
custom sounds from the PC to allow (e.g.) shutter
“Click-Whirr”, or for a “Talking Camera”. This has
limitless possibilities for OEM language
customising or licensing.
Flashgun Support and “Delete Last” FunctionSTV0680B-003 includes flashgun support for an
OEM flashgun module. An additional user interface
function is available in STV0680B-003 which allows
the user to delete the last image, continuous clip or
audio memo which was captured or recorded.
Evaluation Kit and Reference DesignEvaluation kits are available for both standard
features and enhanced STV0680B-003 features.
Precise design guidelines are available from ST as
a separate STV0680B Reference design manual
(see Chapter 12).
Note: Simultaneous audio record and
continuous video capture is not possible.
STV0680B+ VV6410/6411/6500
Table of contents
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61.1 Digital camera chipset ..........................................................................................................6
1.2 Co-processor choices ..........................................................................................................7
1.3 Sensor choices .....................................................................................................................7
1.4 Key system features .............................................................................................................7
Chapter 2 Detailed features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102.1 Sensor type and image formats .........................................................................................10
2.2 User interface .....................................................................................................................11
2.3 Battery level detect and USB auto-switch ..........................................................................13
2.4 Audio record and playback .................................................................................................13
2.5 PC interface options and software support ........................................................................14
2.6 Anti-flicker exposure and gain control ................................................................................15
Chapter 3 Camera modes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163.1 Modes available (STV0680B-001) .....................................................................................16
3.2 Modes available (STV0680B-003) .....................................................................................17
3.3 Description of modes .........................................................................................................17
Chapter 4 STV0680B hardware interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204.1 STV0680B pinout ...............................................................................................................20
4.2 Sensor interface .................................................................................................................20
4.3 Memory interface ...............................................................................................................20
4.4 USB interface .....................................................................................................................22
4.5 UART module for RS232 interface .....................................................................................23
4.6 Power management and battery type ................................................................................23
4.7 Quartz crystal .....................................................................................................................24
4.8 Numeric LCD interface .......................................................................................................24
4.9 Switches and LED’s ...........................................................................................................24
4.10 Flashgun hardware interface (STV0680B-003 only) ..........................................................25
4.11 IR filter ................................................................................................................................25
Chapter 5 Software support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
STV0680B+ VV6410/6411/6500 5.1 General features ................................................................................................................26
5.2 Software installation ...........................................................................................................26
Chapter 6 Detailed chipset specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .286.1 Typical camera specifications ............................................................................................28
6.2 STV0680B companion processor ......................................................................................29
6.3 VV6444 sensor ...................................................................................................................30
6.4 VV6410/6411 and VV6500 sensors ...................................................................................32
6.5 Typical current consumption of complete camera ..............................................................33
Chapter 7 STV0680 Camera System Defect Specification . . . . . . . . . . . . . . . . . . . . . . . . .357.1 General ..............................................................................................................................35
7.2 Defect specification ............................................................................................................35
7.3 Definition of the "Camera System" .....................................................................................35
7.4 Definition of the "Test Conditions" ......................................................................................37
7.5 Definition of a "Major Visible Defect" ..................................................................................37
7.6 Definition of the "Final Colour Image" ................................................................................39
7.7 Definition of a “Minor Visible Defect” ..................................................................................39
Chapter 8 STV0680B pinout information and package dimensions . . . . . . . . . . . . . . . . .408.1 STV0680B pinout ...............................................................................................................40
8.2 STV0680B pin description ..................................................................................................46
8.3 STV0680B package dimensions ........................................................................................47
Chapter 9 VV6410/6411 pinout information and package dimensions . . . . . . . . . . . . . . .489.1 VV6410/6411 pinout ...........................................................................................................48
9.2 VV6410/6411 pin description ............................................................................................49
9.3 VV6410/6411 package dimensions ....................................................................................51
Chapter 10 VV6500 pinout information and package dimensions . . . . . . . . . . . . . . . . . . .5310.1 VV6500 pinout ....................................................................................................................53
10.2 VV6500 pin description ......................................................................................................54
10.3 VV6500 package dimensions .............................................................................................56
Chapter 11 Schematics and example parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5811.1 Schematics .........................................................................................................................58
STV0680B+ VV6410/6411/6500 11.2 Example parts list ...............................................................................................................58
Chapter 12 Evaluation Kit and Reference design manual . . . . . . . . . . . . . . . . . . . . . . . . . .6112.1 Ordering details ..................................................................................................................61
12.2 Technical support ...............................................................................................................62
STV0680B + VV6444/6410/6500
Revision updateMain changes applied since last release, version 3.3: Updated camera defect specification
Introduction STV0680B + VV6444/6410/6500 Introduction
1.1 Digital camera chipsetThis document describes the features and functionality of a CMOS chipset, comprising an
STMicroelectronics (ST) CIF or VGA resolution sensor and an STV0680B companion processor
(DCA1), as well as outlining what peripheral components are required/supported in order to
complete a camera using the chipset. Such a camera is particularly suited to dual-mode digital stills
or toy applications.
In stills mode, the camera stores raw image data in memory. The camera carries out no colour
processing, ensuring its simplicity and low cost. Subsequent download of raw data to a PC or
Macintosh for processing is done through an RS232 or USB interface, through demo software, a
TWAIN driver, or OEM custom application. The license to use the colour algorithm (embedded in
the PC or Mac driver software) is included in the price of the chipset.
A video option is provided, when tethered through USB, which can allow for Video for Windows
applications, and ‘video clips’ can be recorded while untethered by continuously capturing images
while in ‘Continuous’ mode, then downloaded to the PC for playback, using software to create an
AVI file.
Using STV0680B-003, the firmware also includes the capability to trigger a flashgun module
through a two wire interface (enable input and trigger output), and the capability to record audio
sounds into the SDRAM, for subsequent upload to the PC, or to replay audio sounds which have
either been recorded on the camera or dowloaded from the PC (stored on the PC as.WAV files).
Precise design guidelines are available from ST as a reference design (see Section 4). A software
development kit (SDK) for PC is available from ST, to interface to the camera and provide the basis
for developing a custom software application for stills and/or video, which includes colour
processing software as object code.
Figure 1 : Typical camera system block diagram
STV0680B + VV6444/6410/6500 Introduction
1.2 Co-processor choicesTwo revisions of the STV0680B are produced by ST. Although there are certain functional
differences between these revisions, both have an identical pinouts and STV0680B-003 retains all
the functionality of STV0680B-001, hence is backwards compatible.
1.3 Sensor choicesThe following sensors are supported:
1.4 Key system featuresThe key features of a typical camera based on the STV0680B chipset are as follows:
1.4.1 Image features (STV0680B-001) Support for 5V or 3.3V CIF resolution sensor (VV6444 or VV6410/6411) - 352 x 288 pixels Support for 3.3V VGA resolution sensor (VV6500) - 640 x 480 pixels 80 picture storage capacity possible for CIF, with 64MB memory 26 picture storage capacity for VGA, with 64MBit memory
Table 1 : Differences between STV0680B-001 and STV0680B-003
Table 2 : Sensor choices with STV0680B
Introduction STV0680B + VV6444/6410/6500 A greater number of images can be stored when ‘Low’ resolution mode is enabled (e.g. 80
QCIF images with 16Mbit memory, 107 QVGA images with 64Mbit memory). See Table 3. Automatic anti-flicker exposure and gain control
1.4.2 Image features (STV0680B-003) All image features for STV0680B-001 are supported. Support for flashgun.
1.4.3 User features on camera (STV0680B-001) Self-timer mode allows a picture to be captured after several seconds. Twin 7 segment LCD panel supported - showing number of pictures left, and modes. Picture counter helps the user to know how much memory is left. Un-tethered ‘Continuous’ mode allows capture of image sequences for storage in memory and
subsequent download to PC. Piezo buzzer indicates a number of useful events to the user, e.g. whether enough light is
present for picture capture, etc. Indicator LED. “Clear all” function clears camera. “Low Resolution” mode increases number of images which can be captured by reducing image
resolution.
1.4.4 User features on camera (STV0680B-003) All user features of STV0680B-001 are supported. Audio Record function (if audio record hardware detected) allows sounds to be recorded. Audio Playback function (if audio playback hardware fitted) allows sounds which have been
recorded to be played back. “Delete last” function allows user to delete audio memos, pictures or continuous clips, deletion
must be carried out “most reset first”. Camera can be configured by the user to play custom sounds at certain functions, using a PC
application. “Go to sleep” function, whereby the camera can be put into standby mode while untethered.
1.4.5 User features on PC software (STV0680B-001)PC software allows a number of features, including fast download of thumbnail images for picture
selection, and automatic detection and correction of sensor defects. The driver compatibility
includes: TWAIN driver to suit all TWAIN compatible imaging applications Video for Windows PC driver for tethered video mode (through USB), available at all
resolutions, with fastest framerates at QCIF resolution AVI video file creation from image sequences captured in ‘continuous’ mode Quicktime Video driver and Adobe Photoshop stills plug-in for Mac
Custom OEM PC software can be developed by using the SDK (for SDK availability, contact ST), to
upload thumbnails/still images or ‘continuous’ images, e.g. for AVI file creation.
STV0680B + VV6444/6410/6500 Introduction
1.4.6 User features on PC software (STV0680B-003)All PC software written for a STV0680B-001 camera will function with a STV0680B-003 camera
which is only used to take still images/video.
The SDK (version 2.90 or later) allows for: the OEM to write a custom application for uploading sound memos, based on the example
LCDC demo software. the OEM to write a custom application for downloading custom sounds to the camera, based
on the example CustomSound software.
1.4.7 Power management features and USB compliance Retention of pictures, recorded sounds, and downloaded custom sounds with extremely low
power operation, which appears to the user as if the camera is “switched off”. Auto power-off after 30sec with no user activity Operates from 4.5-6V battery, although system voltage is 5V or 3.3V, dependant on sensor. Low battery detection Dependant on hardware configuration, switch-over to USB power supply is supported, to allow
the device to operate with low batteries or without batteries, when connected to USB. Full USB compliance requirements are listed in the USB specification, however, in a camera
designed using this chipset, the following must at least be included: (a) an SDRAM with
sufficiently low self-refresh current, (b) USB inrush protection circuitry, and (c) (in the case of
VV6444 only) a switched 5V sensor supply is used, to maintain sufficient supply voltage to the
5V sensor. See Section 4 for further details.
1.4.8 General features High speed picture/sounds upload to PC/Mac over USB ST Colour processing algorithms included under license (as part of drivers/SDK) USB or RS232 serial interface options, and VfW / TWAIN driver support.
Detailed features STV0680B + VV6444/6410/6500 Detailed features
2.1 Sensor type and image formatsThe sensor type is auto-detected by STV0680B, which ensures that the correct sensor timing is
enabled, and the correct image resolutions are enabled, as shown in Table3.
For stills photography, ‘High’ or ‘Low’ resolution mode can be selected, to give CIF or QCIF pictures
from a CIF sensor, and VGA or QVGA from a VGA sensor (see Table 3). Reduced resolution allows
for storage of more images. Images captured in both ‘High’ and ‘Low’ resolution can be stored in
camera memory at the same time. Therefore there is no need for images stored in memory to be
cleared before changing image resolution.
Where USB is connected, the host PC software (through a Video for Windows driver) can activate
tethered video mode, regardless of the user inputs to the camera buttons. In this case, the image
resolution is controlled by the PC driver.
Note: When tethered VfW video (PC) or Quicktime driver (Mac) is activated, all images or recorded
sounds or video clips will be deleted from the camera SDRAM. A software solution is available
(“Camera control”, as part of the SDK for PC, and “Plug’n Save” for Mac) which can monitor
whether a camera is connected and will warn the user if activating the VfW driver will cause SDRAM
contents to be deleted.
Note:1 VfW framerate is dependent on PC performance and USB bus loading On a camera using STV0680B-003, the number of images which can be stored is reduced if Audio
sounds have been recorded on the camera or if custom sounds have been the
PC to the camera. The reduction of capacity depends on the length of audio clip, but a rough guide
is that if 1 CIF image uses the same amount of SDRAM as 10sec of audio, and one VGA image
uses the same amount of SDRAM as 30 sec. of audio.
Table 3 : Image modes supported (STV0680B-001)
STV0680B + VV6444/6410/6500 Detailed features A CIF camera with STV0680B-001 and 64Mbit SDRAM can store up to 320 images by using QCIF
mode. Where >99 images are still available, the LCD display will remain at 99. Where (no. of
images available) <99, the LCD display will show the number of images available, as is the case
with all other modes.
2.1.1 VV6444VV6444 is a CIF resolution, 5V CMOS imaging sensor and has been superseded by VV6410/6411.
2.1.2 VV6410VV6410 is a CIF resolution, 3.3V CMOS imaging sensor. A brief specification is shown in Chapter6.
A dual design to support VV6444 and VV6410/6411 is not possible, since VV6410/6411 is a 3v3
sensor. A single footprint for VV6410/6411 and VV6500 is not possible since the package types
differ, however, the same support circuit is used.
For IR filter design, the best choice filter follows the GS0034 dielectric stack filter specification,
which is available from ST . An alternative, although not optimal filter, would be Schott S8612 doped
glass, also sold as CM500.
2.1.3 VV6411VV6411 is a CIF resolution, 3.3V CMOS imaging sensor. A brief specification is shown in Chapter6.
The functionality, pixel size, resolution and support circuit are identical to VV6410, however, the
colour filter material is slightly different, and the package type and pinout may differ to VV6410.
Contact ST for further details.
A single footprint to support VV6411 and VV6500 is not possible because of the package difference.
A single footprint to support VV6410 and VV6411 may be possible, dependant on the final package
for VV6411.
2.1.4 VV6500VV6500 is a VGA resolution, 3.3V CMOS imaging sensor. A brief specification is shown in
Chapter6
A dual design to support VV6444 and VV6500 is not possible, since VV6500 is a 3v3 sensor. A
single footprint for VV6410/6411 and VV6500 is not possible since the package types differ,
however, the same support circuit is used. See Chapter6.
For IR filter design, the best choice filter follows the GS0034 dielectric stack filter specification,
which is available from ST . An alternative, although not optimal filter, would be Schott S8612 doped
glass, also sold as CM500.
2.1.5 SDRAM This is covered in more details in Chapter4.
2.2 User interfaceThe user interface supported by STV0680B comprises of user controls, buzzer sounds or
customised audio sounds and visual displays.
2.2.1 Push buttonsThe following are the functions which are supported by the chipset. These functions are achievable
with no more than 2 push buttons.
Detailed features STV0680B + VV6444/6410/6500 Mode button (Wake-up/Switch between modes): This button allows the user (1.1) to wake the
camera up from standby mode when the camera is to be used for taking pictures, or (1.2) to
switch between modes of operation shown in Chapter3. Shutter button (Shutter/confirm action): This button allows the user to take a picture or confirm
an action, as shown in Chapter3
The modes of operation are described in Chapter3.
It may also be desirable to include an on-off slider switch. This has advantages and disadvantages,
and its exact function is discussed further in the reference design available from ST.
Where a flashgun module is included in the camera, it will be necessary to include a flash on/flash
off push button or slider switch, dependant on the exact flashgun module design. possible
implementations are discussed in a separate application note AN1312 regarding flashgun
implementation, available from ST.
2.2.2 LED indicatorAn LED display camera status, i.e. to show that the camera is not in Standby/PC suspend mode.
2.2.3 Picture counter using 2 x 7 segment displaySTV0680B stores a picture counter value, which shows how many images can still be captured.
STV0680B supports a 2x7 segment LCD panel. In ‘Snapshot’ mode and continuous capture mode,
this LCD panel displays the number of pictures still available, which is useful to identify when the
user is approaching the maximum number of images which can be stored (see Table 3). It is
possible to clear the images stored in memory, in order to continue taking pictures. In other modes,
this LCD panel shows displays a 2-character code, which helps the user to navigate around the
modes.
Note: A CIF camera with STV0680B and 64Mbit SDRAM can store up to 320 images by using QCIF
mode. Where >99 images are still available, the LCD display will remain at 99. Where (no. of
images available) <99, the LCD display will show the number of images available, as is the case
with all other modes.
For suitable numeric LCD panel types, see Section 4.8.
2.2.4 Piezo buzzer An on-chip Pulse Width Modulator (PWM) on STV0680B is used to generate buzzer sounds to
signal certain events. The following are typical of the type of events which are indicated by the
buzzer, and each has its own distinctive sound: Camera has been ‘Woken up’ from standby mode (either by the user pressing a button, by re-
connecting the power source, or by connecting a USB/RS232 connection). Camera has been ‘gone to sleep’ i.e. moved into standby mode. Pictures are retained in
memory. Picture has been successfully taken after the user presses the capture button. Picture has NOT been taken after the user presses the capture button. This indicates to the
user that there is insufficient light, or that the exposure control was not ready due to a rapid
change of lighting in the scene. Picture has NOT been taken after the user presses the capture button, due to picture counter
having reached the maximum number of images. The user has the chance to zero the counter
if desired. End of continuous capture in un-tethered ‘Continuous’ mode, due to memory full. Self-timer activated and counting down.
STV0680B + VV6444/6410/6500 Detailed features
2.2.5 Custom soundsA camera which includes STV0680B-003 and Audio playback hardware can have a set of custom
sounds a PC application. A different sound can be associated with each of the
following functions:
Note:1 Where a given function has a sound associated with it stored in SDRAM, the piezo buzzer does not
give any beeps for that function. Not all functions need to have custom sounds associated with
them, this is the choice of the user or OEM. A demonstration PC application “CustomSounds” is available from ST, however this is not intended
for end-users. Source code is available which allows the EOM to build their own PC application
using the SDK.
2.3 Battery level detect and USB auto-switchAn on-chip battery level detector on STV0680B detects when the battery voltage falls below a
threshold. This threshold is determined by the designer, dependant on the perception of what
remains as ‘acceptable’ image quality as the battery voltage falls. The chosen threshold level is
determined by a resistor value, as shown in Chapter 6 Where no USB has been detected, the LCD
display flashes, which indicates that the battery is low. Where a USB connection has been detected,
the camera sources power from USB, if certain additional hardware is fitted.
Note: It may be a requirement of certain USB compliance tests that such additional hardware is included
in the camera design, in order to enable the camera to switch to supply from USB and hence report
back to the PC while connected to the USB bus without a battery.
2.4 Audio record and playback
2.4.1 RecordA camera which includes STV0680B-003 and a microphone, comparator and other periphery (also
utilizing the sensor pre-amplifier) can be used to record sounds which are stored in the same way
as images. STV0680B-003 will auto-detect the presence of Audio record hardware and include
Table 4 : List of custom sound functions
Detailed features STV0680B + VV6444/6410/6500 audio record and “delete last” functions into the user interface. The audio sample rate is 11.025kHz,
and the signal is digitised using a successive approximation A-D converter with 8 bits resolution.
The SDRAM stores 1 second of Audio recording per 11k Bytes of memory.
2.4.2 PlaybackA camera which includes STV0680B-003 and an amplifier, speaker/headphone socket, and other
periphery, can be used to playback sounds which were either recorded on the camera or
the PC.
The quality of Audio playback is largely dependant on the type of speaker used, and on the correct
mounting of the speaker in the camera plastics.
2.5 PC interface options and software supportEither USB Interface (full speed 12Mbit/sec. max.) or RS232 interface (115.2Kbaud) is supported
by the chipset, with driver software available from ST for both. The interface type is auto-detected
by the chipset. PC software can be one of the following: Simple image upload demonstration software supplied by ST, allowing uploading of stills or
‘continuous’ images. This software should not be supplied as an end-user product. TWAIN driver to suit all TWAIN compatible imaging applications Video for Windows driver for tethered video mode (USB only) Custom end-user software developed by OEM using SDK (for SDK availability, contact ST).
The SDK is supplied by ST as a 32-bit DLL format, running on Windows 98, and accessed
through a documented software interface. This provides the basis for developing a custom
software application for uploading stills and/or video.
2.5.1 USBComplete images (displayed as either thumbnails or in full resolution), or the entire SDRAM
contents (e.g. for uploading continuously captured image sequences, recorded using ‘Continuous
Capture’ mode) can be downloaded through USB, and USB connection also allows for tethered
video mode to be activated by the USB driver.
Thumbnail image download is extremely fast for the entire memory contents in the camera. Once a
picture is selected for download, full image download takes approximately 0.15 seconds per image
for a CIF image (0.6 seconds for a VGA image), plus post processing time per image.
For USB interface details, see Section 4.4.
Note: Actual USB download and post processing time also depends on PC performance and USB bus
loading
2.5.2 RS232 Thumbnails of images, complete stored images, or the entire SDRAM contents can be downloaded
through RS232, but tethered video is not supported.
Once a picture is selected for download, full image download takes approximately 10 seconds per
image for a CIF image (around 30 seconds for a VGA image), plus post processing time per image
(of the order of 1 second approximately).
For RS232 interface details, see Section 4.5.
Note: Actual post processing time after RS232 download also depends on PC performance
STV0680B + VV6444/6410/6500 Detailed features
2.6 Anti-flicker exposure and gain control
2.6.1 GeneralThe chipset operates automatic exposure and gain control for either 50Hz or 60Hz mains-driven
indoor lighting, using the same 12MHz crystal. This improves picture quality by selecting a set of
exposure values which minimise ‘flicker’ effects. Detection of the mains frequency is dependant on
the status of the GPIO3 pin, which can be achieved by population of a PCB link at a late stage in
production, once the country of destination is known, without the need to change the crystal
frequency.
The auto exposure and gain algorithm is always enabled during Snapshot’/self-timer/continuous
mode. When the shutter button is pressed in ‘Snapshot’ mode, the chipset captures an image if the
exposure and gain value has reached a suitable value for the current scene. If the light detected has
suddenly changed, the camera may emit an audible tone to indicate that more time is required to
reach the correct exposure target. In ‘Snapshot’ mode the chipset only captures the image data if
sufficient light is present in the image. In continuous capture mode, the chipset captures images
regardless of whether enough light is present.
The exposure control algorithm in STV0680B chooses exposure values which minimise “flicker”
effects from occurring under fluorescent lighting. STV0680B can only prevent flicker in lighting
powered by 50Hz or 60Hz electricity supply, but automatic detection of the flicker frequency is not
possible. Hence choosing the correct anti-flicker setting is important, in order to prevent dark stripes
form appearing across the image, and this selection must be done in hardware.
Figure 2 : Illustration of flicker problem
2.6.2 Flashgun exposureWhere STV0680B-003 and a flashgun module are included in the camera, and the flashgun enable
signal is HIGH, the exposure mode will operate in a different manner. The CMOS sensor
progressive scan readout requires that the sensor is set to maximum exposure so that all lines are
being exposed at a certain point in time.
The “window” within which the flashgun needs to fire in order to correctly expose all sensor lines is
of the order of a few 100μsec (contact ST for more precise details), therefore the flashgun module
design should have reached maximum light output within this period after the falling edge of the
flash trigger output from STV0680B-003.
Possible flashgun implementations, regarding hardware interface, charge sensing, and flash
energy required are discussed in a separate application note AN1312 regarding flashgun
implementation, available from ST.
Camera modes of operation STV0680B + VV6444/6410/6500 Camera modes of operationThis section refers to the two switches as discussed in section Section 2.2.1 “Mode”: connects GPIO0 pin of STV0680B to GND when pressed “Shutter”: connects GPIO1 pin of STV0680B to GND when pressed
Pressing the mode switch repeatedly cycles through a series of modes as displayed on the LCD.
When a given mode is displayed it may be selected by pressing the shutter button. If an option is not
selected within 5 seconds the display will revert to showing the number of available pictures.
3.1 Modes available (STV0680B-001)Note that the number of images displayed depends on the sensor and SDRAM type - see Table3.
STV0680B + VV6444/6410/6500 Camera modes of operation
3.2 Modes available (STV0680B-003)
Figure 4 : STV0680B-003modes (CIF camera with 16Mbit SDRAM assumed)
3.3 Description of modesNote that certain modes are only available using STV0680B-003, and with appropriate hardware
fitted on the camera.
3.3.1 Standby mode (untethered) and Wake-upOn power-up, or wake-up from untethered standby mode, (i.e. by pressing the Mode button), the
camera will beep twice. The LCD will briefly indicate the camera resolution either ‘Hr.’ for high
resolution (80 CIF or 26 VGA images - using 64Mbit memory) or ‘Lr’ for low resolution (322 QCIF or
107 VGA images - using 64Mbit memory) and then display the number of pictures which may be
taken. Please note that in Low Resolution Mode, although there can be up to 322 images available,
the LCD counter will only go up to 99, it will continue reporting 99 until there are less than 99 images
left.
The camera will go back to standby mode either after 30 seconds of inactivity, LED1 will turn off and
the LCD will go blank. This can also be done (STV0680B-003 only) by pressing the mode switch for
more than 2 seconds.
3.3.2 Normal modePressing the shutter button will take a picture. The camera will beep. A high pitched beep indicates
that the picture was taken successfully and the counter will decrement (if there are less than 99
images left to take). A low beep indicates insufficient light to take a picture. A series of beeps
indicates that the camera is full.
Camera modes of operation STV0680B + VV6444/6410/6500 Stored pictures may be uploaded to a PC at any time, whether or not the camera is full. Plugging the
USB connector into the camera will cause it to reset and issue a double beep but all stored pictures
will remain. When the USB connector is unplugged the camera will go to sleep. When connected to
the PC the camera may still be used in the normal way.
whether or not there is sufficient light.
3.3.3 Audio record - ArThis mode is available on STV0680B-003 only, with audio record hardware fitted.
Pressing the shutter button within 5 seconds will cause the camera to start recording for as long as
the shutter button is pressed down. If the shutter button is not pressed within 5 seconds the camera
will revert to normal picture taking mode. Whilst recording, the LCD display flashes ‘Ar’. If the
recording stops because the memory is full, the ‘memory full’ audio tone is sounded and the display
will stop flashing and display ‘00’. The audio data is digitised and stored in SDRAM.
3.3.4 Audio Playback - APThis mode is available on STV0680B-003 only, with audio playback hardware fitted.
Pressing the shutter button within 5 seconds will cause the camera to play back the most recent
audio recording. If the shutter button is not pressed within 5 seconds the camera will revert to
normal picture taking mode. Whilst playing, the LCD display flashes ‘AP’.
Once in Audio Playback mode, repeated presses of the shutter button will step the camera through
each of the audio recordings in the camera (most recent first). Keeping the shutter button pressed
down will also cycle through the audio recordings. Pressing the mode button during playback will
stop the audio clip.
Note: Minimum audio recording length is set to 0.5 seconds.
3.3.5 Delete last object - dA/dP/dCThis mode is available on STV0680B-003 only, with audio record hardware fitted.
If the last object captured was an audio recording 'dA' (delete audio) will be displayed, if the last
object was an image, then 'dP' (delete picture) will be displayed, or, if the last object was part of a
continuous capture sequence, then 'dC' (delete continuous) will be displayed. If the camera is
empty, the mode will be suppressed. The mode works in the same way as ‘CL’ (Clear All), i.e. once
the mode is selected, pressing the shutter button once will cause the camera to beep and ‘dA’, ‘dP’
or ‘dC’ to start flashing. Pressing the shutter button again within 5 seconds will delete the last audio
clip, picture or continuous capture sequence.
STV0680B + VV6444/6410/6500 Camera modes of operation
3.3.6 Continuous mode - CtPressing the shutter button within 5 seconds will cause the camera to start taking pictures for as
long as the shutter button is pressed down (and the camera is not full). If the shutter button is not
pressed within 5 seconds the camera will revert to normal picture taking mode.
Note:1 During continuous mode the camera will allow pictures to be taken regardless of the available light,
which could result in insufficient exposure. In continuous mode, only every alternate field is grabbed hence capture rate is halved. E.g. 12.5fps
CIF and 7.5fps VGA On STV0680B-003, Continuous Mode is suppressed when the FlashGun enable signal (GPIO2) is
high.
3.3.7 Self timer - StPressing the shutter button will now start a 10-second self-timer. The camera will issue a short beep
every second and then a longer beep. A further beep will then indicate that the picture has been
taken (high beep - picture successful, low beep - insufficient light, picture not taken). The self-timer
mode can not be selected when the camera is full. The self-timer countdown cannot be stopped
once it has started.
3.3.8 Clearing the camera memory - CLPressing the shutter button once will cause the camera to beep and the ‘CL’ to start flashing.
Pressing the shutter button again within 5 seconds will clear all the images/audio clips in the
camera and reset the counter.
3.3.9 Changing picture resolution - Hr/LrThe resolution option is displayed, either Hr. to change to high-resolution mode (if currently in low-
resolution mode) or Lr to change to low-resolution (if currently in high-resolution mode). Press the
shutter button within 5 seconds of selecting the resolution option, the camera will beep and the
display will reset indicating the number of pictures available in the new mode. The picture resolution
can be changed at any time, i.e. the camera can store both high and low resolution images.
STV0680B hardware interfaces STV0680B + VV6444/6410/6500 STV0680B hardware interfaces
4.1 STV0680B pinoutThe STV0680B pinout has been carefully developed to minimise the physical size of the support
printed circuit board by facilitating placement of and electrical routing to peripheral support
components such as the SDRAM. The complete pinout and listing is shown in Chapter6
4.2 Sensor interfaceSTV0680B uses a standard ST digital interface from the sensor, and the sensor clock input is
provided by an output from STV0680B. Designing a camera using this chipset should design as
close as possible to the reference design (Chapter 6), in which case the chipset can be regarded as
a functional ‘black box’, and no further details regarding the STV0680B-sensor interface are
required.
4.3 Memory interfaceSTV0680B is designed to interface to an external 16Mbit or 64Mbit SDRAM (see Table 3). The
SDRAM device must have a 16 bit wide data bus and operate from a 3.3V supply. Two sizes of
SDRAM memory are supported by STV0680B, 16MBits (1M x 16 bits wide) or 64MBits (4M x 16
bits wide), the memory size is auto-detected by STV0680B. STV0680B clocks the SDRAM at
6MHz, typically this is well below the figures offered by most manufacturers’ devices. Devices which
are PC66 and/or PC100 compliant are preferred. For interface wiring, see Chapter6
4.3.1 SDRAM current consumptionFor maximum system battery life while no pictures are being taken, and to assist in meeting
requirements for USB compliance, an SDRAM should be chosen with the lowest possible self
refresh current specification. For suggested SDRAM part numbers, see Chapter6
In addition, the USB suspend mode current specification requires that the camera will consume no
greater than 300μA when un-tethered. Meeting this specification, which is included in the
requirements for USB compliance, assumes an SDRAM with up to approximately 250μA self-
refresh current, based on a current consumption of approximately 50μA for STV0680B+support
circuit.
4.3.2 SDRAM interface timing requirementsThe following timing diagrams should be referred to when selecting SDRAM other than those
recommended in Chapter6
STV0680B + VV6444/6410/6500 STV0680B hardware interfaces
Figure 5 : SDRAM read timing (16Mbit device, burst read)
Figure 6 : SDRAM write timing (16Mbit device, burst write)
STV0680B hardware interfaces STV0680B + VV6444/6410/6500
Table 5 : Timing parameters for SDRAM read/write
4.3.3 SDRAM refresh periodThe SDRAM refresh period from STV0680B is guaranteed to be no greater than 15.6μS during
‘Snapshot’/self-timer/continuous/tethered video modes of operation (i.e. not standby mode). In
standby mode, the SDRAM is set to self-refresh, therefore no refresh from STV0680B takes place.
4.3.4 SDRAM initialisation periodThe SDRAM initialisation period is currently set to 981μS in STV0680B.
4.4 USB interfaceSTV0680B includes a USB Version 1.1 compliant Universal Serial Bus Interface, including a
transceiver. This allows direct connection from STV0680B to a USB connector with minimal
additional hardware (i.e. a small number of passive discretes) - see Chapter6
The USB interface interfaces the STV0680B to the USB at full speed 12MHz data rate. Some of the
features are: Compliant with USB protocol revision 1.1. USB protocol handling. USB device state handling. Clock and data recovery from USB. Bit stripping and bit stuffing functions. CRC5 checking, CRC16 generation and checking. Serial to parallel conversion. Single bulk end point.
USB drivers are supplied by ST. For USB timing information, please refer to the USB specification
V1.1.
STV0680B + VV6444/6410/6500 STV0680B hardware interfaces
4.5 UART module for RS232 interfaceThe UART module on STV0680B provides a 115200 baud full duplex interface to an external Host.
4.5.1 RS232 physical interfaceSTV0680B does not support direct connection to a serial link. Physical line driver circuitry is
required, e.g. using a standard RS232 transceiver chip, or by using a small number of low cost
discretes (as shown in Chapter 6). The schematics shown assume a 3 core cable with a length of
no greater than 2m. Unscreened cable can be used, a suitable low cost connector is a 3.5mm audio
jack plugs/sockets.
4.5.2 UART module overviewReceiving data
The UART module in STV0680B receives serial data through the RXD pin. Data reception is
initiated by a 1-to-0 transition on RXD, and the received data is sampled every 8.66μS.
If the RXD input is not 0 when the incoming data is first sampled, the UART module goes back to
look for another 1-to-0 transition. This is to provide rejection of false start bits. If the start bit proves
valid, reception of the rest of the frame will proceed.
Transmitting data
When a transmission is activated by STV0680B, the contents of an internal transmit shift register
are shifted onto the TXD pin, every 8.66μS.
The UART operates at 12MHz, which is not an integer multiple of 115200, so the actual baud rate is
115232 +/- 0.3%, which is well within the requirements of a typical 16x oversampling UART, which
can tolerate a 3.75% error in baud rate.
4.6 Power management and battery typeSTV0680B and the SDRAM require a 3.3V supply. Where a VV6410/6411 or VV6500 (3.3v) sensor
is used, a single voltage regulator can be used to regulate the supply for all three components from
the battery, or the sensor on-board VReg can be used. Where a VV6444 is used, the sensor
requires a 5V supply, hence a DC-DC converter is recommended to provide enough voltage when
the camera is powered from the USB bus. These are explained more fully in the reference design.
4.6.1 Power switching to USBIncluded in the USB compliance requirements, is the ability of the camera to report to the PC when
connected to the USB bus, whether or not there is a fresh battery in the camera. This means that
power sourcing from USB is required, which also saves on battery life while the camera is used in
USB tethered video mode. In order to allow switching from battery to USB power, some additional
hardware is required (see also Chapter6): The USBDETECT input to STV0680B is used to detect that a USB power supply is connected If the USB is detected, additional hardware is used to switch off the battery An inrush protection circuit can protect the USB bus from current draw in the case of a low
battery/battery not fitted. This may be necessary to comply with the USB specification.
For precise USB compliance requirements, please consult the USB specification version 1.1
4.6.2 Switched sensor supplyDependant on the hardware implementation, the SENSPWR output from STV0680B can be used to
power off completely the sensor during Standby mode (in the case of VV6444) or put the sensor
STV0680B hardware interfaces STV0680B + VV6444/6410/6500 into Suspend mode (in the case of VV6410/6411/6500). This has a significant improvement on
battery life.
4.6.3 Battery typeThis is hardware dependant. The schematics referred to in Chapter 6 assume either three or four
1.5V cells.
4.7 Quartz crystalRegardless of the sensor type or anti-flicker requirements, the sensor + STV0680B chipset
operates from a single 12MHz fundamental quartz crystal. For specification requirements, see
Table 13. STV0680B includes an on-chip low jitter PLL, for PLL characteristics, see Table 12.
4.8 Numeric LCD interfaceSTV0680B supports a 2-digit LCD panel only, for alpha-numeric display.
4.8.1 LCD typesSTV0680B connects to a non multiplexed, direct drive LCD with 2 x 7 segments. Many LCD types
are compatible with this interface. The LCD refresh frequency is 34.7Hz.
4.8.2 LCD interface pinoutThe convention for segment numbering is as follows: ’0’ connects to segment ’a’, ’1’ connects to
segment ’b’, and so on, where a to g are standard for all 7-segment displays, as well as an LCD
common output, giving fifteen signals in total.
4.9 Switches and LED’sThe GPIO lines on STV0680B have pre-defined functions as follows, see Section 2.2 for user
interface functionality, and Chapter 6 for precise hardware implementation
4.9.1 MODE push button and SHUTTER push button: GPIO0 and GPIO1Both push button inputs have internal de-bounce circuits, reducing the amount of hardware required
externally. It is recommended that labelling is used on the camera casing to help the user
understand the functioning of the 2-button interface.
4.9.2 Input to select between 50 and 60Hz flicker frequency: GPIO3This allows for factory setting of the anti-flicker frequency, dependant on the final country of
destination. See also Section 2.6. The polarity of this selection is detailed in the reference design
(see Chapter6).
4.9.3 LED indicator output: GPIO5The LED output has an 8mA current sinking capability.
4.9.4 Other pins: GPIO2, 4, 6, 7With STV0680B-001, these pins are un-used and should be tied to GND.
STV0680B + VV6444/6410/6500 STV0680B hardware interfacesWith STV0680B-003, these pins are used, as detailed in Table6.
Their specific functions are detailed in the reference design and in the following documents
available from ST: Audio: Application note AN1310 Flashgun: Application note AN1312
4.9.5 Audio record hardware interface (STV0680B-003 only)The firmware implements a successive approximation A/D conversion by outputting successive
analogue levels through the DAC output, which are compared with the actual signal level (output
from the sensor microphone preamplifier), and the resultant high or low signal from the comparator
is read at GPIO4. The sampling frequency is 11kHz, and the successive approximation is done at 8
bits resolution per sample. It is not possible to speed up the sampling frequency due to the limitation
of STV0680B firmware speed.
An actual hardware implementation is given in the audio application note AN1310.
4.9.6 Audio playback hardware interface (STV0680B-003 only)The firmware outputs the desired signal level through the DAC output, which is amplified to the
speaker or headphone socket. GPIO6 is used to switch off the amplifier during periods of audio
recording, to prevent the successive approximation waveform from being heard during periods of
recording, and to reduce the power consumption and unwanted crackle through the speaker.
An actual hardware implementation is given in the audio application note AN1310.
4.10 Flashgun hardware interface (STV0680B-003 only)STV0680B-003 will revert to flashgun exposure when it detects GPIO2 is high. Ideally the hardware
should combine the two factors of (a) user intention (e.g. user switches on flashgun) and (b) charge
sensing (i.e. flash is charged up and ready to fire).
These two factors (a) and (b) are independent, since there may be a delay of several seconds
between switching on the flashgun charger, and the flashgun being able to fire. To revert to flashgun
exposure before the flashgun is completely charged up would cause very bad pictures to be taken
in low light conditions because there is no “low light” threshold when flashgun exposure is enabled,
since the camera expects a flash to fire. A suggested flashgun hardware interface is given in the
flashgun application note AN1312.
When flashgun exposure is enabled and the shutter button is pressed, a picture will be taken and
the flash trigger pin GPIO7 will be pulsed low at the correct point in time so that all lines of the
CMOS imager are exposed.
4.11 IR filterAn Infra-Red Blocking Filter is required to achieve correct colour response. The exact specification
for the IR filter characteristics are given in the reference design manual.
Table 6 : Other GPIO usage with STV0680-003
Software support STV0680B + VV6444/6410/6500 Software support
5.1 General featuresThe chipset is a dual-mode camera, i.e. stills and video, and is supported by a range of
demonstration software, standard drivers, and software development options.
Driver software is available to support both USB and RS232 interface including standard TWAIN
and video for Windows drivers (VfW through USB only) for Win98/Win2k/WinME. Quicktime drivers
and a Photoshop stills plug in for MacOS 8.6/9.0/9.1 are also supported.
Example software applications (PC only) are provided to create .AVI video files from untethered
continuous capture of images (AVICreator), to upload still images and recorded sounds
(LCDCdemo) and to download .WAV files from the PC to the camera (CustomSound). In each case,
PC source code is provided to assist in OEM software development using the SDK.
ST colour processing and defect detection/correction software runs on the host and is supplied
under licence agreement, as part of all host software/drivers/SDK.
5.1.1 Still image uploadThis is available through demonstration software, OEM custom software, or using standard TWAIN
applications. Features include: Fast upload through USB, or upload through RS232. Colour display of image thumbnails for picture selection. Download of full image once selected by user software. Automatic detection and correction of sensor defects Colour processing of full image, using the ST colour process
The above features also apply to “AVI Creator” or any OEM custom software for AVI video creation
from pictures taken while un-tethered, since this is essentially a “stills” function.
5.1.2 Streaming video (only while tethered to USB)This is available through demonstration software, or using standard VfW applications. Features
include: Streaming video through standard VfW driver Automatic detection and correction of sensor defects Colour processing of full image, using the ST colour process
5.2 Software installationThe following software support is only available to OEMs. Access to the latest installation files is
possible through a password-protected web page, contact ST for details. The install file gives the
option to install: Drivers (always check web site for latest driver version). EVK software, i.e. LCDCdemo.exe and AVIcreator.exe, G2Video.exe, and CTItest2.exe SDK installation: source code for sample applications, and documentation
STV0680B + VV6444/6410/6500 Software support
5.2.1 Driver support available
5.2.2 EVK softwareNote: The following is also supplied with evaluation kits/demonstration units, but all the following software
is only for demonstration purposes and should NOT be supplied as an end-user product. However,
application-level source code (i.e. not driver/colour processing source) for LCDCdemo.exe, AVI
creator, and CTItest.exe is available as part of the SDK, which allows similar applications to be built
by the software developer: Simple demonstration software LCDCdemo.exe for uploading thumbnails and images.
AVIcreator.exe software for uploading continuous images for creating ‘movie’ clips. G2Video.exe is a VfW application which shows streaming video while tethered to USB and allows creation of.AVI video clips.
CTItest.exe is only for debugging purposes, for software developers using the SDK
5.2.3 Software Development Kit (SDK) and source codeA software development kit allows the OEM to develop a custom application which calls the same
range of drivers as listed in Section 5.2.1, hence allowing the OEM application to perform picture
download, thumbnail display, and colour processing using the ST colour process. Inclusion of
source code for the applications listed in Section 5.2.2 allows the software developer to use these
as the basis for their own application.
The SDK is supplied by ST as a 32-bit DLL format, running on Windows 98/Win2KTM , and accessed
through a documented software interface. Development requires Microsoft Visual Studio Ver. 6 or
later. This provides the basis for developing a custom software application for stills.
Note: Source code for PC Drivers, Defect Correction, and Colour Processing algorithms are not available.
Table 7 : Driver choices
Detailed chipset specifications STV0680B + VV6444/6410/6500 Detailed chipset specifications
6.1 Typical camera specificationsThe following data assumes that the camera has been built according to reference design shown in
Chapter6
Table 8 : Typical camera specificationsNote:1 Dual USB or battery power supply is only possible when the required power switching
hardware is included, as shown in Chapter6 Figures are approximate and depend on actual components sources.
Table 9 : Approximate shutter speeds
STV0680B + VV6444/6410/6500 Detailed chipset specifications
6.2 STV0680B companion processorNote:1 VDI = |(D+) - (D-)|
2VCM includes VDI range.
3TF RFM =(TFR / TFF).
Table 10 : STV0680B specifications
Table 11 : STV0680B USB specifications
Detailed chipset specifications STV0680B + VV6444/6410/6500 DRV includes an external resistor of 20 Ohms serial to this transceiver.
6.3 VV6444 sensorThis has been superseded by VV6410/6411
Table 12 : STV0680B PLL characteristics
Table 13 : STV0680B crystal tolerance
Table 14 : VV6444 specificationsNote:1 48dB refers to VV6404. With the addition of microlenses on VV6444, an increase in
sensitivity can be expected. Where the sensor is completely powered off by a FET or switch (external hardware) during
the Standby/PC Suspend Mode. Where the FET/switcher is not implemented, and the sensor is powered throughout
Standby/PC Suspend Mode, however the sensor clock is disabled.
STV0680B + VV6444/6410/6500 Detailed chipset specifications
Table 14 : VV6444 specificationsNote:1 48dB refers to VV6404. With the addition of microlenses on VV6444, an increase in
sensitivity can be expected. Where the sensor is completely powered off by a FET or switch (external hardware) during
the Standby/PC Suspend Mode. Where the FET/switcher is not implemented, and the sensor is powered throughout
Standby/PC Suspend Mode, however the sensor clock is disabled.
Detailed chipset specifications STV0680B + VV6444/6410/6500
6.4 VV6410/6411 and VV6500 sensorsNote:1 Assuming appropriate external hardware recommendations are implemented (see Chapter 6), the
sensor SUSPEND pin is asserted during Standby Mode/PC Suspend Mode. Hence the sensor is
placed in Sensor Suspend mode by means of (a) a Serial interface message and (b) the SUSPEND
pin being asserted. Where the external hardware does not permit the sensor SUSPEND pin to be asserted (during
Standby Mode/PC Suspend Mode, the sensor is placed in Sensor Suspend mode by means of a
Serial interface message only. This increases current consumption due to a pull-up on the
SUSPEND pin. This only applies to VV6500.
Table 15 : VV6410/6411 specifications
Table 16 : VV6500 specifications
