V2 Proof
Test Circuit PCB
The first go round, I'm trying to debug a host interface, and have a working camera to boot. In order to expedite things a bit, I have taken the Audine Project camera, and made the following modifications:
- Beefed up the power supply.
- Added an emitter-follower to the front end.
- Added an offset adjustment to the final amp.
- Replaced the AD976 with an LTC-1605.
- Added a PIC17C44 to control it.
- Added a shutter control line.
In playing with the Quickcam Grayscale, I developed an attachment to the idea of having the camera do the camera stuff, and the PC do the PC stuff. To this end, I designed this board with a PIC17C44 CPU to run the show on the camera end. It is code compatible with the PIC17C756 CPU I plan on using in the finished product, so I don't have to waste any time rewriting the code. The camera part is entirely (with the exception of the above outlined mods) an Audine camera.
The PCB is 4.4 inches x 4.0 inches. It has separate digital and analog ground planes, and separate grounds for the digital, analog, and clock circuits. Video comes from the camera on a coaxial cable, while the power and clocks go up on a ribbon. The distance from the board to the camera head is anticipated to be less than six inches - maybe as little as four inches.
If all goes well, the second test will move everything on the northeast corner (the KAF specific circuitry) to another board, and change the analog circuit to include a sample hold amp. The sample hold amp is only to gain flexibility in digitizing the signal.