I know this is a long post, but I have a lot of questions.
I’ve been thinking about making a PC controlled robot (not for FIRST). I was planning to use an EDU controller to control the motors and a serial interface from a PC to send motor commands to the controller. I was thinking of using a MiniBox picoPSU-120 and standard computer parts(the celeron 1.2 ghz desktop thats laying in my basement ). Does anyone see a reason this power supply wouldn’t work?
Next, I was considering using web cams on this robot(color tracking). Has anyone tried this, and if they did how?
What kinds of safeties could I use? the robot will be autonomous and wireless, and I don’t want it running away.
Also if I made this work is their any reason I couldn’t use this on a FIRST robot? I have read the 2006 manual, and I don’t see anything to prohibit it. I know believe I can make this work for around $300(no single part should be more than about $75 so it should pass the $200 electronics rule) and -15 lbs.
EDIT: as I was looking I found this PSU M1-atx it is also manufactured by minibox, but has high voltage tolerances.
I should have been more clear. If I was going to use this for FIRST i would migrate the code from the EDU controller to the FRC controller, and also add more information to the data sent from the controller so it included the joystick inputs and other onboard inputs.
But since I don’t have access to an FRC control system, and I thought this might be fun to try i thought an EDU controller would work for now.
Hmm I agree for a normal desktop mainboard, I wouldn’t choose to use the Pico PSU. You may want to underclock your celeron to decrease power usage and probably run w/o a direct CPU fan if you don’t need 1.2ghz of speed.
Web cams for color tracking: yes this can be pretty easily implemented depending on your knowledge of API for the OS you are using. In visual basic (its not a very good choice for algo processing) I could get about 2 fps at 320x240 @ 24bit rgb tracking changes in movement. Couple two webcams to your rig and you may be able to try out duo-vision algorithms such as those to measure distance. :yikes:
Safeties: IMHO standard stuff such as stopping-on-loss-of-signal would be great. Your controller can monitor data from your PC and slow your bot to a stop when there is suddenly no data after lets say 0.5s, and your PC can stop your systems if there is a connection loss (depending what method of wireless comms you are using) after 1 second.
In addition you may want to try out low-latency audio/video streaming technologies too
Normally using the picoPSU-120 should not be a problem unless your choice of motherboard is very power demanding. Also consider your storage media, memory and video card: these can draw a lot power causing you PC board not to boot.
Another possible problem is startup and shut down, the computer need adequate time to perform these functions else you risk software corruption and hardware failure.
This site has a variety of 12v DC-DC power supply up to 250W