Trouble with the new PCB version 1.2

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Trouble with the new PCB version 1.2

Postby tec » Fri Feb 11, 2005 6:43 pm

Hello Everyone,
I just received my new AVRCam and assembled it. I cam do several commands but there are some that I cannot succefully do. The following commands are succeful:

PG
GV
CR
DT
SM

The unit hangs up when I try the important commandslike ET and DF. I have tried both hyperterm and AVRCamView to get these two commands to work. I understand that this is a new PCB. Has anyone succefully commanded the new AVRCam (as of Feb 1st) to dump frames or track (ET)? I ohmed out the traces and check all of the voltages on the camera and Tiny12P. Every pin seems to have the right voltage. I don't have an oscilliscope but everything else looks good. I also succesfully changed a register which tells me that the camera oscillator is running.

Anyone have any ideas?

Thanks,
Tim
tec
 
Posts: 3
Joined: Fri Feb 11, 2005 6:34 pm
Location: Alabama

Postby Guest » Sat Feb 12, 2005 4:36 pm

Hello,
I built and tested a v1.2 AVRcam PCB before I shipped the orders out. I was able to perform all the command successfully, including ET/DF. The only thing I can think of that is different between the two setups is that I was using a slightly older version of the AVRcamVIEW software to test the system out (I didn't test it out with Hyperterm).

Couple of questions here:
1) You said that you tried to execute the commands in both AVRcamVIEW and Hyperterm, right? When you executed, say, the DF command in Hyperterm, do you even get the ACK? The ACK should come, followed by a bunch of gibberish (which is the pixel info sent from the camera for each line).

2) Can you check the version of software on the AVRcam, and double check that it is v 1.4...I am 99% sure I double checked this before I sent them out, but it would be worth checking.

There were a couple of issues early on with the AVRcam locking up after a bunch of consecutive frame dumps, but these should have been taken care of in v 1.4 (I tested it a bunch, and also got feedback from people in the field using the system that v 1.4 seemed to fix the issues they were seeing).

I've sent several systems out so far with v 1.2 of the hardware...anyone else seen this behavior? Don't worry Tim...we'll get to the bottom of this...
I am actually in France right now, and won't be getting back to the states until next weekend. I'll have intermittent internet access between now and then, but I'll try to check back here when I get a chance.
Guest
 

Trouble with the new PCB version 1.2

Postby tec » Sun Feb 13, 2005 9:04 am

Hi John,
Thanks for your commitment. I did get ACK's back on both the DF and ET but the pixel data did not come across the RS232. I think the problem lies between the Camera and the uController because I can talk to the uController (i.e. get version 1.4) but when the ucontroller tries to get any camera data, it fails.

I did try version 1.07 of the Windows software. The build date is 2/6/05. I first tried to use the AVRCamView then switch over to hyper term when I could not get data from the camera.Both performed the same way.

Can you tell me what the Tiny12P does in the circuit? Is the clock internal RC network. How does you uController run without an external clock?

Thanks,

Tim
tec
 
Posts: 3
Joined: Fri Feb 11, 2005 6:34 pm
Location: Alabama

Postby Guest » Sun Feb 20, 2005 9:12 am

Hi Tim,
Finally back here in the states...

I powered up a version 1.2 AVRcam when I got back, and re-verified that all the commands worked, and they did. I was able to dump frames as well as track objects.

I then uninstalled the AVRcamVIEW software, and installed the latest one that was on the CD that shipped to you, since this was the only difference between my setup and yours. This was also successful in performing both the frame dumps as well as object tracking.

Couple of more questions for you:
1) You said that you do receive the ACKs after the DF/ET command, right? If this is the case, the AVRcam has entered into ether dump mode or tracking mode (depending on which command is sent). In these modes, the system is dependent on a few critical signals generated by the OV6620. Namely, the VSYNC, HREF, and PCLK signals are used to sample pixels, determine when a line of pixels is complete, and several other tasks. If any of these lines were not connected for some reason, the system would appear to hang after the commands were sent. I just checked the continuity on my board, and everything appears connected (which makes sense since I was able to get the proper response from the system). Try ohmming out the connections of these lines between the camera module and the mega8 to make sure that they are connected properly (see the schematic for the exact connections/pins). Also, verify that they are not tied down high or low permanently (accidental short to ground or something). If you have access to an oscilloscope, check to ensure that these lines are changing states when doing a frame dump.

2) What kind of power source are you using to power the AVRcam? I have seen very bizarre behavior with the system when I was accidentally powering it with less than 5V going into the 5V regulator (I was feeding it around 4.4V). Can you verify that, when powered up, your board is getting at least 5.5V at the Vin terminal?

Oh yeah...the tiny12 is used to turn on the external clock output of the OV6620 so that the mega8 has a clock source. It sends a couple of I2C commands to the OV6620, and then doesn't perform any further useful activity. I posted this in another thread as well, and will be getting the source code for this up on the site soon.

Let me know how these tests turn out...I'll keep thinking about what the culprit could be.
Guest
 

fixed the PCLK signal

Postby tec » Sun Feb 27, 2005 7:33 pm

I fixed it. There was something shorting under the camera connector P18 tothe P17 or P15. This caused the PCLK to short to GND. Thanks for your help. All the functions work now ncluding the ET and DF commands.

Tim
tec
 
Posts: 3
Joined: Fri Feb 11, 2005 6:34 pm
Location: Alabama


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