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DeveloperPermalink Reply by Olivier ADLER on June 4, 2011 at 5:36am

 

 

According to Ardupilot Mega Schematics v 1.2,  PWM Outputs 7 and 8 do comes from PE5 and PE4 AVR Mega outputs.

PWM Outputs 1 to 4 do come from the multiplexer circuit 74LS157.

 

Port E on AVR Mega does not have high driving capabilities. Only port B has high current outputs. It is possible that PE4 and PE5 AVR outputs do not have enough drive capability for your ESC.

 

Or you could have a problem on your AVR Mega chip, or a short on this output with an adjacent wire, or a bad solder somewhere.

Eventually a problem on the ESC input (too low impedance). Did you try another ESC ? A too low impedance input on your ESC could work on a receiver output, but not on the port E AVR output.

 

Last, could be a problem in the code, but this is less probable.

 

If i remember a discussion i had a few weeks ago a Ardupirate developper has reported that some AVR outputs could become wrong after overloading.

 

If you can put a scope on this output and compare with other outputs, you will get your answer. if you see a distorded signal, then you have a hardware problem. If you see only bad pulse timings, then it's probably a software problem.

 

I would vote for the hardware problem with 75 % confidence.

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Permalink Reply by luispez on June 5, 2011 at 8:30am

Thanks for your answer. I think like you, it`s a hardware problem.

I have reviewed all the welds and connectios and are ok.I fear it´s the Ardupilot.

All outputs work well under the 8.

Can I change the output number 8 by 10?  Or is labor?

Has this happened to anyone?

Thanks.

 

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