SGS Thomson Microelectronics STV0680B Datasheet

STV0680B+ VV6410/6411/6500

DUAL-MODE DIGITAL CAMERA CHIPSET

DESCRIPTION

STMicroelectronics Imaging Division has enhanced the feature set of the STV0680B low cost dualmode camera chipset to allow a new line of low cost cameras or toy products to be brought to the market.

STANDARD FEATURES

ST 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) an d downloadi ng 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 Playback

The enhanced features included in STV0680B-00 3 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” Function

STV0680B-003 includes flashgun support for an OEM flashgun module. A n additio nal u ser in terface function is available in STV0680B-003 w hich allows the user to delete the last image, continuous clip or audio memo which was captured or recorded.

Evaluation Kit and Reference Design

Evaluation kits are available for both standard features and enhanced STV0680B-003 features. Precise design guidelines ar e avai l able fr om ST as a separate STV0680B Reference design manual (see

Chapter 12

Note: Simultaneous audio record and

continuous video capture is not possible.

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Table of contents

Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

1.1 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

2.1 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

3.1 Modes available (STV0680B-001) .....................................................................................16

3.2 Modes available (STV0680B-003) .....................................................................................17

3.3 Description of modes .........................................................................................................17

Chapter 4 STV0680B hardware interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

4.1 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

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5.1 General features ................................................................................................................26

5.2 Software installation ...........................................................................................................26

Chapter 6 Detailed chipset specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

6.1 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 . . . . . . . . . . . . . . . . . . . . . . . . .35

7.1 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 . . . . . . . . . . . . . . . . .40

8.1 STV0680B pinout ...............................................................................................................40

8.2 STV0680B pin description ..................................................................................................46

8.3 STV0680B package dimensions ........................................................................................47

Chapter 9 VV6410/6411 pinout information and package dimensions . . . . . . . . . . . . . . .48

9.1 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 . . . . . . . . . . . . . . . . . . .53

10.1 VV6500 pinout ....................................................................................................................53

10.2 VV6500 pin description ......................................................................................................54

10.3 VV6500 package dimensions .............................................................................................56

Chapter 11 Schematics and example parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

11.1 Schematics .........................................................................................................................58

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11.2 Example parts list ...............................................................................................................58

Chapter 12 Evaluation Kit and Reference design manual . . . . . . . . . . . . . . . . . . . . . . . . . .61

12.1 Ordering details ..................................................................................................................61

12.2 Technical support ...............................................................................................................62

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Revision update

Main changes applied since last release, version 3.3:

● Updated camera defect specification

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Introduction STV0680B + VV6444/6410/6500

1 Introduction

1.1 Digital camera chipset

This 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 camer a is particul arly 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 avai lable from ST, to interface to th e camera a nd provid e the basis for developing a custom software application for stills and/or video, which includes colour processing software as object code.

LED

GPIO

Sensor

I/F

PWM

Flashgun

Enable/Trigger

LCD

memory

Driver

STV0680B

I/F

RS232

I/F

USB

I/F

Detect Low

Battery

2 x 7 seg. LCD

16MBit or 64MBit

SDRAM

Transceiver

Circuit (Discretes)

Power

Management

Circuit (Discretes)

RS232 interface to PC

USB interface to PC

4.5 - 6v Battery e.g.

3-4 x AA, AAA, etc.

OEM Flashgun

Module

Subject

CMOS Sensor

VV6410/6411(CIF)

VV6500 (VGA)

Enable/Trigger

Lens +

IR Filter

Audio

Pre-Amp

Image Array

VReg

Audio

Speaker

Microphone

Amplifier

Sensor data

Sensor clock

Piezo

Buzzer

Push

Buttons:

“Mode”

“Shutter

/Record”

Comparator

Audio DAC

12MHz XTAL

3v3 supply

4-5v (Nominal) supply from Battery or USB

Figure 1 : Typical camera system block diagram

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1.2 Co-processor choices

Two 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.

Order number STV0680B-001 STV680B-003 Silicon revision Firmware revision

Sensor supported

SDRAM supported

USB RS232 Video for Windows support Flash-gun support Audio record + playback Custom sounds

Table 1 : Differences between STV0680B-001 and STV0680B-003

1.3 Sensor choices

The following sensors are supported:

STV0680B STV0680B

v1.00 v3.00

VV6444 VV6410 VV6500

16Mbit

or 64Mbit

Yes Yes Yes Yes Yes Yes

No Yes No Yes No Yes

VV6444 VV6410 VV6411 VV6500

16Mbit

or 64Mbit

Sensor Resolution Sensor supply voltage

VV6444 VV6410/6411 VV6500 VGA (640 x 480)

Table 2 : Sensor choices with STV0680B

1.4 Key system features

The 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

CIF (352 x 288)

3.3v

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● 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

● Automatic anti-flicker exposure and gain control

Table 3

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’ mo de all ow s captur e of i mage sequen ces for storage i n mem ory 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 incre ases number of images wh ich can be captur ed 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 t he SDK (for SDK a vailabilit y, contact ST), to upload thumbnails/still images or ‘continuous’ images, e.g. for AVI file creation.

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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 configura t io n, swit ch-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.

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Detailed features STV0680B + VV6444/6410/6500

2 Detailed features

2.1 Sensor type and image formats

The 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

For stills photography, ‘High’ or ‘Low’ resolution mode can be sele cted, to give CIF or QCIF pictures from a CIF sensor, and VGA or QVGA from a VGA sensor (see 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.

Table 3

). Reduced resolution allows

Sensor

VV6444 CIF 352 x 288

VV6410/ 6411

VV6500 VGA 640 x 480

Sensor

Image Size

CIF 352 x 288

Max. no. of

images

Resolution

mode

High CIF 352 x 288 20 80 15 frames/sec.

Low

High CIF 352 x 288 20 80 15 frames/sec.

Low

High VGA 640 x 480 (6) 26 2 frames/sec.

Low

Table 3 : Image modes supported (STV0680B-001)

Final Image Size

QCIF 176 x 144

(Subsampled)

QCIF 176 x 144

(Subsampled)

QVGA 320 x 240

(Subsampled)

stored in

16MBit

memory

(

Note 2

(26)

)

Max. no. of

images

stored in

64MBit

memory

(

Note 2

)

322

Note 3

(see

322

(see

Note 3

107

Note 3

(see

Approximate

VfW framerate

25 frames/sec.

)

22.5 frames/sec.

)

12 frames/sec.

)

Note: 1 VfW framerate is dependent on PC performance and USB bus loading

2 On a camera using STV0680B-003, the number of images w hich can be stor ed i s reduced if Aud io

sounds have been recorded on the camera or if custom sounds have been downloaded from 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.

(

Note 1

)

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3 A CIF camera with STV0680B-001 and 6 4Mbi t SD RAM can store up to 320 i mag es by using QC IF

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 VV6444

VV6444 is a CIF resolution, 5V CMOS imaging sensor and has been superseded by VV6410/6411.

2.1.2 VV6410

VV6410 is a CIF resolution, 3.3V CMOS imaging sensor . A brief specification is shown in 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, al though not optimal filter, would be Schott S8612 doped glass, also sold as CM500.

2.1.3 VV6411

VV641 1 is a CIF re solution, 3.3V CMOS imag ing sensor. A brief specification is shown in 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 VV641 1 a nd VV6500 is not possible because of the package dif ference. A single footprint to support VV641 0 and VV6411 may be possible, dependant on the final package for VV641 1.

2.1.4 VV6500

VV6500 is a VGA resolution, 3.3V CMOS imaging sensor. A brief specification is shown in

Chapter 6

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

Chapter 6

2.1.5 SDRAM

This is covered in more details in

2.2 User interface

The user interface supported by STV0680B comprises of user controls, buzzer sounds or customised audio sounds and visual displays.

2.2.1 Push buttons

The following are the functions which are suppor ted by the chipse t. These functio ns are achievabl e with no more than 2 push buttons.

Chapter 4

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1 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

2 Shutter button (Shutter/confir m acti on)

an action, as shown in

Chapter 3

: This button allows the user to take a picture or co nfirm

Chapter 3

The modes of operation are described in It may also be desirable to include an on-off slider switch. This has advantages and disadvanta ges,

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.

Chapter 3

2.2.2 LED indicator

An 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 display

STV0680B stores a picture counter value, which shows how many images can still be captured.

STV0680B supports a 2x7 segment LCD panel. In ‘Snap shot’ mode and contin uous capture m ode, 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 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

Table 3

). It is

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:

1 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).

2 Camera has been ‘gone to sleep’ i.e. moved into standby mode. Pictures are retained in

memory. 3 Picture has been successfully taken after the user presses the capture button. 4 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. 5 Picture has NOT been taken after the user presses the capture button, due to picture counter

having reached the maximum num ber of i ma ges. The u ser ha s the cha nce to zer o th e counte r

if desired. 6 End of continuous capture in un-tethered ‘Continuous’ mode, due to memory full. 7 Self-timer activated and counting down.

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2.2.5 Custom sounds

A camera which includes STV0680B-003 and Audio playback hardware can have a set of custom sounds downloaded from a PC application. A different sound can be associated with each of the following functions:

Power On Sound delete Power Off Continuous clip delete Good picture Clear memo ry Bad picture

(Normally due to insufficient light) Memory full Low power Self timer #1 Flashgun ON Self timer #2 Flashgun OFF Low resolution Flashgun Trigger High resolution Frequency 50kHz Picture delete Frequency 60kHz

Table 4 : List of custom sound functions

Confirm action

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.

2 A demonstration PC application “CustomSoun ds” 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-switch

An 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 sho wn in display flashes, which indicates tha t the battery is low . Whe re a USB connection ha s been detected, the camera sources power from USB, if certain additional hardware is fitted.

Chapter 6

Where no USB has been detected, the LCD

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 th e camera to switch to supply fr om USB and hence r eport back to the PC while connected to the USB bus without a battery.

2.4 Audio record and playback

2.4.1 Record

A camera which includes STV0680B-003 and a mi croph one, comparator and other peripher y (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

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Detailed features STV0680B + VV6444/6410/6500

audio record and “delete l ast” functions int o the user i nterface. The a udio 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 Playback

A 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 downloaded from the PC.

The quality of Audio playback is largely depe ndant 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 support

Either 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:

1 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. 2 TWAIN driver to suit all TWAIN compatible imaging applications 3 Video for Windows driver for tethered video mode (USB only) 4 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 USB

Complete 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 enti re memory cont ents in the camer a. Once a picture is selected fo r down load, full image download takes approximately 0.15 seconds per ima ge 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

2.5.2 RS232

Thumbnails of images, complete stored images, or the entire SDR AM 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 ( aro und 3 0 second s for a VGA i mage), plus post processing time pe r i m age (of the order of 1 second approximately).

For RS232 interface details, see

Note: Actual post processing time after RS232 download also depends on PC performance

Section 4.5

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STV0680B + VV6444/6410/6500 Detailed features

2.6 Anti-flicker exposure and gain control

2.6.1 General

The 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 ‘f li cker’ effects. Detection o f the mai ns fr equen cy is dep endan t 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 captu res an image if the exposure and gain value has reached a suitable val ue for the current scene. If the li ght 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-fli cker setting is importan t, in order to prevent da rk stripes form appearing across the image, and this selection must be done in hardware.

Flicker setting not correct Flicker setting correct

2.6.2 Flashgun exposure

Where STV0680B-003 and a flashgun module are in cluded 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.

Figure 2 : Illustration of flicker problem

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.

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Camera modes of operation STV0680B + VV6444/6410/6500

3 Camera modes of operation

This section refers to the two switches as discussed in section

● “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)

Normal: 20 / 80

Continuous Capture: Ct

Self-Timer: St

Clear All: CL

Re solution: Hr / Lr

Press Mode button

After 30sec of inactivity

Standby mode (u ntethered)

Section 2.2.1

Figure 3 : STV0680B-001modes (CIF camera with 16Mbit SDRAM assumed)

Note that the number of images displayed depends on the sensor and SDRAM type - see

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STV0680B + VV6444/6410/6500 Camera modes of operation

3.2 Modes available (STV0680B-003)

Normal: 20 / 80

Audio Record: Ar

Audio Playback: AP

De lete Last: dA / dP / dC

Continuous Capture: Ct

Self-Timer: St

Clear All: CL

Re solution: Hr / Lr

Press Mode button

After 30sec of inactivity

Standby mode (u ntethered)

Notes:

1. Audio Record only available if audio hardware is fitted

2. Audio Playback only available once an audio clip has been recorded

3. Delete Last displays (only available if audio hardware fitted) dA - if the last object is an audio clip dP - if the last object is a picture dC - if the last object is a continuous capture clip

The mode is inhibited if the camera is empty.

4. Continuous Capture mode is inhibited when the flashgun is enabled

(SW 6 down)

Figure 4 : STV0680B-003modes (CIF camera with 16Mbit SDRAM assumed)

3.3 Description of modes

Note 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-up

On 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 - usi ng 64Mbit memo ry) or ‘Lr’ for low resolution (32 2 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 t here can be up to 322 images availab le, the LCD counter will only go up to 9 9, it will contin ue reporting 99 un til 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 al so be done (STV 0680B-003 only) by pressing t he mode switch f or more than 2 seconds.

3.3.2 Normal mode

Pressing the shutter button will take a pi cture . T he camer a wi ll beep. A h igh pi tched beep indi cates 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.

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Camera modes of operation STV0680B + VV6444/6410/6500

Stored pictures may be uploaded t o a PC at any time, whether or not the ca mera is full. Plugging the USB connector into the camera will cause it to r eset and issue a double b eep but all stored p ictures will remain. When the USB connector is unplugged the ca mera will go to sleep. When connected to the PC the camera may still be used in the normal way.

Note

: With the flashgun enabled (STV0680B-003 only) the camera will always take a picture,

whether or not there is sufficient light.

3.3.3 Audio record - Ar

This mode is available on STV0680B-003 only, with audio record hardware fitted. Pressing the shutter button with in 5 secon ds w ill cause the camera to start recordi ng for as l ong as

the shutter button is pressed down. If the shutter butto n is not pressed withi n 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 so unded and the displa y will stop flashing and display ‘00’. The audio data is digitised and stored in SDRAM.

3.3.4 Audio Playback - AP

This 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/dC

This 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 b eep and ‘dA’, ‘dP’ or ‘dC’ to start flashing. Pressing the shutter butto n again within 5 seconds will delete the l ast audio clip, picture or continuous capture sequence.

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STV0680B + VV6444/6410/6500 Camera modes of operation

3.3.6 Continuous mode - Ct

Pressing 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 wil l allow picture s to be ta ken regardl ess of the ava ilable light,

which could result in insufficient exposure.

2 In continuous mode, only every alternate field is grabb ed hence capture rate is halved. E.g. 12.5 fps

CIF and 7.5fps VGA

3 On STV0680B-003, Continuous Mode is suppressed w hen the Fl ashGun ena ble signal ( GPI O2) is

high.

3.3.7 Self timer - St

Pressing 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 - CL

Pressing 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/Lr

The resolution option is displayed, either Hr. to change to high-resolution mode (if currently in lowresolution 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 resolut ion can be changed at any time, i.e. the camera can store both high and low resolution images.

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