Connecting 7.2V (directly) to camera

[scottmso]

I'm trying to set up our CMUcam to connect directly to the PC (via serial.) However, I can't find a cable to connect the 7.2V battery to the camera unit. Is there a pre-made cable to do this or am I expected to do this myself? (I was thinking about cutting one of the battery to RC cables to fit since it's a female connector) Any advice appreciated - thanks

[devicenull]

The easiest way to get power to the camera is a PWM cable from one of the RC's PWM ports to the power in port on the camera. The manual really isn't written that clearly, but powering the camera off the RC is the easiest option.

[Mike AA]

When I tested ours about an hour ago I had to run the camera directly off the RC ( Robot controller). You do this with the PWM cables. Connect the PWM cable to port J2, on the "bottom" of the camera board. Located next to the tiny switch. Connect the other end of the cable to a PWM port on the RC, doesn't matter which one as it only uses the port for power. Next connect the backup batter (blue package about 3x2) to the RC, using the 5 inch long adapter cable. then connect power via the 12 volt battery to the RC, please run through the breaker/fuse box. Your camera should zero out and there should be one or two lights on the camera.

-Mike

[tml240]

Hello,

I got my camera working today through last year's controller (w/ PWM and such) and played around with Labview and it worked fine..

and I want to keep the topic in here since I had the same question..

Is there anyway to put NiCad pack directly to the power port on the Control Board? I want to work with the camera at home and the workbook doesn't specify how to hook it up with out going through RC. (other groups aside from the camera crew could be using it so..)

[scottmso]

It looks like we're going to try to splice together a PWM cable and a backup battery cable now. Would this cause any major problems? I'm hoping not. I guess I'll see and I'll come back with the results in a day or two...

[tml240]

Originally Posted by scottmso

It looks like we're going to try to splice together a PWM cable and a backup battery cable now. Would this cause any major problems? I'm hoping not. I guess I'll see and I'll come back with the results in a day or two...

*hoping for a good update..

i stripped the PWM cables and was about to hook it up to the battery pack, but i wasnt sure with a few things:
- Aside from pwr lines (red and black) what do i do with white one in the middle?
- Frying the battery? (i can probly put together to make my own but..)
- Frying the $200.00+ Camera board?

[DonRotolo]

Originally Posted by tml240

*hoping for a good update..

i stripped the PWM cables and was about to hook it up to the battery pack, but i wasnt sure with a few things:
- Aside from pwr lines (red and black) what do i do with white one in the middle?
- Frying the battery? (i can probly put together to make my own but..)
- Frying the $200.00+ Camera board?

the RED wire is +7.2 volts DC
The BLACK wire is Ground
The white wire is unused

Be ABSOLUTELY SURE you have the Polarity of both ends (the battery AND the plug onto the camera right - there is NO reverse polarity protection on the camera board and it WILL fry. Triple check, then check again. really.

Anyway, you can power the camera board from most any source of 6 ro 15 volts DC that can supply 200 mAmps. the 7.2 volt backup battery - or an R/C battery - is just fine.

Don

[scottmso]

Originally Posted by Don Rotolo

the RED wire is +7.2 volts DC
The BLACK wire is Ground
The white wire is unused

Be ABSOLUTELY SURE you have the Polarity of both ends (the battery AND the plug onto the camera right - there is NO reverse polarity protection on the camera board and it WILL fry. Triple check, then check again. really.

Anyway, you can power the camera board from most any source of 6 ro 15 volts DC that can supply 200 mAmps. the 7.2 volt backup battery - or an R/C battery - is just fine.

Don

I know to be very careful - I think we're going to have the NiCad battery one one end and a regular 3-pin PWM connector on the other. I'm guessing it means that if we plug it in backwards nothing will really happen because the 3rd pin (where the +7.2V is going to) is disconnected.

I found this: http://www.cs.cmu.edu/~cmucam2/CMUcam2_manual.pdf which says the same thing, that any input 6-15 volts can be used. By the looks of it, these CMUCam2 boards are a lot different than the FIRST ones. However, are they (for the most part) electrically identical?

Thanks

[Drok00]

we actually just did the exact same thing you are talking about yesterday and ended up frying the nice new $200 camera board... we hooked the pwm cable up to the 7.2 volt battery and plugged it into the camera itself, we then plugged the serial cable into the computer and im not entirely sure what happened ( our programmer was playing around with it but i saw the setup and talked to him afterwards) he said he jsut turned it on, and then i saw this giant cloud of magic smoke... ( and he reacted rather slowly... so the smoke continued to pour out) i would not suggest not running it through the RC!! set it up through the RC for power if you can.. unless he did somehting wrong when setting it up ( i dont think he did) frying it could be a real possibility!

[scottmso]

Originally Posted by Drok00

we actually just did the exact same thing you are talking about yesterday and ended up frying the nice new $200 camera board... we hooked the pwm cable up to the 7.2 volt battery and plugged it into the camera itself, we then plugged the serial cable into the computer and im not entirely sure what happened ( our programmer was playing around with it but i saw the setup and talked to him afterwards) he said he jsut turned it on, and then i saw this giant cloud of magic smoke... ( and he reacted rather slowly... so the smoke continued to pour out) i would not suggest not running it through the RC!! set it up through the RC for power if you can.. unless he did somehting wrong when setting it up ( i dont think he did) frying it could be a real possibility!

Ouch...

I wonder if he wired it backwards?

And does anyone know how much voltage the PWM connectors we're supposed to connect the CMUcam put out? thanks

[scottmso]

We plugged it in via the 7.2V with an adapter we threw together, and it hasn't let the smoke out yet, and both LEDs come on. We're going to try it with LabView, will keep you updated...

[scottmso]

Alright, we're having some problems. I can't get LabView to see the camera (I get an error message when I try to run it.) I can get an output from the CMUcam in HyperTerminal, but all I get is the message that says CMUcam and the version, and sometimes an "ACK". Sometimes the letters in HyperTerminal are off. (like !CK rather than ACK) Any ideas on how I can get this working? I've tried two different serial cables, and I've made sure the baud settings in Windows/HyperTerminal are set to what they should be (according to the manual). Any advice greatly appreciated - thanks!

[devicenull]

Originally Posted by scottmso

Alright, we're having some problems. I can't get LabView to see the camera (I get an error message when I try to run it.) I can get an output from the CMUcam in HyperTerminal, but all I get is the message that says CMUcam and the version, and sometimes an "ACK". Sometimes the letters in HyperTerminal are off. (like !CK rather than ACK) Any ideas on how I can get this working? I've tried two different serial cables, and I've made sure the baud settings in Windows/HyperTerminal are set to what they should be (according to the manual). Any advice greatly appreciated - thanks!

Did you install the VISA app on the labview driver CD? The camera gui seems to need it to work, did you change the com port it was using too? (Box in top left corner)

[mechanicalbrain]

Just curious, I'm remembering our accelerometers from last year and wondering if red = power and white = signal or reversed. Has anyone tried to plug the camera into the RC, pull out their handy dandy multimeter, and get some readings? Also pwm (Im assuming the camera works on the same voltage) output 5 volts 7.2 may be too much. If I were to power it directly, and I'm still not sure why I you need to or are willing to risk expensive hardware to do it, I would use a reliable power source like my handy dandy (I like that term) PC power supply as apposed to a chemical battery.

[scottmso]

Not sure if we installed the VISA app on there - someone else installed LabView. And I didn't change the serial port. It was on COM1 the whole time which is my only serial port.

And I'm not sure whether or not plugging in the 7.2V hurts the camera or not. I noticed one of the chips (the relatively large square one on the left-bottom corner of the board) was getting a little hot. Is this normal? I was thinking that the hot chip may be a symptom of feeding it too much voltage, or maybe it just gets hot.