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Author Topic: Apexis APM-h803 help me connect via serial?  (Read 5393 times)

April 26, 2013, 06:00:16 pm
Hi guys

I bricked my APM-H803 by running the wrong firmware (still worked) but I think this put a wrong resolution (with a little help from me) in a config file somewhere.  Now with the original firmware installed, the unit is bricked.

I ordered a UART from ebay and with eagerness tried to hook it up today.  Unfortunately once I got the camera open it wasn't obvious where the pins were and I could find very little about how to identify the connection points either specifically for this camera or in general.

Hopefully someone here feels like giving a few pointers to get me started.

Here's a picture. The candidate spot I noticed is in the top left corner of the picture. (no pins, just holes)

Here's the image:

« Last Edit: April 26, 2013, 06:01:53 pm by bluenote »

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April 26, 2013, 06:21:33 pm
The 4 holes based on the picture. Looks like where the serial interface is located.

Have you looked on the other side of the PCB ("Printed Circuit Board") to see if there are any designations for those holes on the other side of the board?


April 26, 2013, 07:29:13 pm
Hey Don

The other side of the board labels those pins only "J4".  Can you tell me how to go about trying to hook up my UART to that in the sense of, how would I go about eliminating or beginning some combinations?


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April 26, 2013, 07:35:33 pm
Hey Don

The other side of the board labels those pins only "J4".  Can you tell me how to go about trying to hook up my UART to that in the sense of, how would I go about eliminating or beginning some combinations?

You are very welcome.

Would you be able to take a picture of the other side of the entire board? Much like you have taken a picture of this side of the board.

The issue is that the side of the board you have a picture of. Is not showing any of the connections that are going to these holes.

So maybe by looking at the other side of the board. It will be easy to determine what hole is the ground ("GND") and which one is the +DC hole.

For sure. You do NOT want to use the +DC voltage wire on your serial UART interface. You only want to use the GND, TX and RX wires.

If we can determine the GND hole and the +DC hole ("Which we want to avoid") then worse case the TX and RX holes may need to be reversed ("50 percent chance"), but that would help determine where those holes are. Getting TX and RX reversed won't cause damage to the camera or the UART. Crossing the GND and/or +DC on the other hand, could damage the camera or the UART.

Also, do you have a volt meter?

« Last Edit: April 26, 2013, 07:48:50 pm by TheUberOverLord »

April 27, 2013, 01:22:13 pm

Hi Don

I hope these are good enough, if not I will try and brave the rats nest and get enough stuff disconnected to get right in there.


EDIT: I have a multimeter and I can probably , I say probably, use it in a useful manner.
« Last Edit: April 27, 2013, 01:24:26 pm by bluenote »

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April 27, 2013, 01:51:16 pm
Sadly. In this case. Because the board is multi-layered. There are no signs of what the holes are connected to on any side of the board itself.

It might be better to ask the seller if they can provide you the information on what hole is what.

While you could use a volt meter to try and determine what hole is what. Done wrong the camera or the UART could be damaged in the process.


April 29, 2013, 12:52:48 pm
Thanks Don.  I've just emailed them so I'll check back when I get an answer. Otherwise I'll have to try trial and error I guess.

May 03, 2013, 02:12:50 pm
So far, no response back, I will email again and then would appreciate any suggestions on the best way to least riskily trial and error this ?


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May 03, 2013, 09:06:56 pm
If you put a volt meter on each of the pins and confirm they are 3.3V or less, then it is no problem to connect your 3.3V UART to any of those pins to see if you get anything showing up in your terminal emulator.

Just put your UART's RX pin on each of the camera's pins and power cycle the camera, and see if you get any data showing up.  Try it at the most common 115200bps 8N1 rate, and if that doesn't work try a few other ones like 57600 or even 9600.