A Universal Arduino Camera Shield  

Table of contents

Purpose

Learn your arduino to see with this shield. This arduino camera shield is based on the pic based sstv system but was modified to use the arduino atmel instead of the pic.

 

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Features

As the original SSTV board, the Arduino Camera Shield provides a C3188A camera module which uses an OV7620 CCD chip, a TC74 temperature sensor, and a battery backed DS1307 real time clock. New on the board ist a MAX7456 on screen character display. Compared to the SSTV system the camera shield does not provide any audio functions used for SSTV operation. For this, specialised audio shields could be used. You can find informations for a lot of shields at the shield list

The camera default run's in 640 x 480 pixel mode and outputs a analog S/W NTSC video signal which can be routed via some jumpers through the MAX7456 OSD character generator to insert text into the video signal. This can be used to show informations like the temperature or the time on screen.

When a picture is captured the camera is put into 320 x 256 mode and a color image is placed into the AL422B SRAM chip. This chip is only capable of holding one QVGA 320 x 256 color image. The image comes directly from the CCD and is not a digitized frame of the analog video signal. So every text inserts done by the MAX7456 are NOT visible in the capture.

The captured Image can then be transfered to the PC in either raw or converted as windows bitmap format.

Schematics

Will follow shortly

The PCB

The pcb is a standard, arduino shield sized, double layered one. All of the parts are more or less small SMD parts so soldering without a steady hand and good tools is not that easy. If some functions of the board are not needed or required the parts for this functions dont need to be soldered. Click on the images to enlarge.

pcb top view   pcb bottom view
 
 
 
 
Various views of the finished camera shield
 
 

You can download a PDF File with the schematic and the PCB here and the firmware arduino sketch here.
If you dont have the Adobe Acrobat Reader installed on your machine you can find it here

Usage

The firmware for this shield consists of some libraries for the TC74, the DS1307 and the C3188A. Place this libraries in your arduino IDE library path. And a simple sketch which allows one to try all functions of the board. It's possible to read the temperature, read and set the time, take pictures, transfer this pictures in various ways to a PC and dump some important CCD registers. So it's mainly a test firmware to try out the board. There is also a simple Windows software available which allows to control the board without a terminal program and also to watch captured images. See a screenshot below.

Notes & Comments

in the Press

This paper can also be found in the german HAM Radio Magazine
"Funkamateur" at www.funkamateur.de, Issue 10 / 2012, Page 1037,
Title: "Kamera-Shield auf Arduino-Basis für ein SSTV-Sendemodul"

Credits

If you have any comments or sugestions just drop me a line.

73, OE1RIB