My CMUCam may be fried?

[futz]

I dug out my CMUCam (the original) and hooked it up. Wrote some code but couldn't get it to do anything. Even the demo mode did nothing. Huh...

I continued trying things until I noticed when picking it up that the regulator (LM2940-5.0) was HOT!! I put a meter on some VDD/VSS pins on the board and it was getting something like 13.3V. The SX28AC75/DP MCU was pretty warm too.

It was working last time I used it years back. I assume the regulator failed somehow while it was stored. How could that happen? Static electricity?

So, do y'all think it's fried? Absolute maximum VDD is 7.0V. I guess the camera might be toast too?

I had it connected to the 18F1320 on my Junebug. RB1 is burned. I replaced the chip and the new one's RB1 works. The old one didn't.

Luckily I didn't fry my , which was connected too.

If the CMUCam is a goner I think I might buy a CMUCam2 or maybe even the new CMUCam3. They're neat toys to tinker with. I once had a robot with this cam on it that would chase a hockey ball around.

 

[dknguyen]

There might be a short (from a trace or from some silicon failing) or the regulator might have failed and is the short itself. If you can replace the regulator, it's worth a try.

If it's a short somewhere else...that's a massive pain to find and if it happened inside an IC you are pretty much outta luck.

Do you measure a low resistance between power and ground (on either the input side of the regulator or the output side of the regulator?). How about when you connect power? Do you measure zero volts between power and ground (on either the input side of the regulator or the output side of the regulator?)

How do you even get 13V on the CMUCam board? I thought it was only fed with 5-7V or something like that.

 

[futz]

There might be a short (from a trace or from some silicon failing) or the regulator might have failed and is the short itself. If you can replace the regulator, it's worth a try.

If it's a short somewhere else...that's a massive pain to find and if it happened inside an IC you are pretty much outta luck.

Do you measure a low resistance between power and ground (on either the input side of the regulator or the output side of the regulator?). How about when you connect power? Do you measure zero volts between power and ground (on either the input side of the regulator or the output side of the regulator?)

Ok, I'll try some of that tonight after work. Thank you. There's still a tiny bit of hope I guess.

How do you even get 13V on the CMUCam board? I thought it was only fed with 5-7V or something like that.

If there's a reg onboard I routinely just use one of the two or three wall wart plugs that are always on the desk. That one is a universal unit set for 12V, I think. It usually powers my breadboards. Since I don't need 12V for anything anymore (needed it for one thing a while back) I should really set that thing back down to 9V. A bit safer for small electronics.

 

[dknguyen]

CMUCam 3 looks realy cool compared to the previous versions though, so I wouldn't fret too much about getting a new one lol.

 

[futz]

Seems I was mistaken. The rumors of my CMUcam's demise have been greatly exaggerated.

I was measuring my voltage in the wrong place. Turns out that the servo output isn't regulated. Luckily the servo survived the high voltage.

I swapped out the regulator anyway, though the old one was probably fine.

I rigged a serial cable and plugged a MAX232 into the empty socket on the CMUcam board. Started Tera Term and powered up the CMUcam, and she lives! I get the usual "CMUcam v1.12" bootup response.

Guess I should double-check that 18F1320 before I chuck it. Maybe I was wrong about that burned pin too.

CMUCam 3 looks realy cool compared to the previous versions though, so I wouldn't fret too much about getting a new one lol.

The CMUcam 3 is nice, but it's a tad expensive at $240. I want one anyway. CMUcam2 is $180.

 

[futz]

My CMUcam turns out to be 100% OK. I was totally out to lunch on the fried call (pun intended). I now have quick and dirty code running on the 18F1320 and it's tracking a hockey ball pretty well.

The CMUcam's onboard servo control is X axis only, and it's jerky. I hate it. I set up the camera on my **broken link removed** today and will be writing code so the 18F1320 will control the servos to track in both X and Y axis, and do it smoothly.

One day I think I might write some Python code to grab frames and display them on the PC. The Java program that used to be available for the CMUcam isn't available anymore (at least not without a huge fight), so a good replacement is needed. And Java sucks! I very much prefer Python. There's virtually no software out there for the CMUcam. Too bad. It's a neat sensor.