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DeveloperPermalink Reply by John Arne Birkeland on August 28, 2012 at 4:59am

Actually the wiki is lagging, so with the new firmware (standard on 2.0 and 2.5) all versions should use the input pin 2&3 jumper method. The solder-bridge alternative is more like an idiot prof backup solution, bypassing the entire ppm encoder hardware and sending the PPM signal straight to the main chip.

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DeveloperPermalink Reply by R_Lefebvre on August 28, 2012 at 6:47am

Do you know for sure that method works?  Because I tried it on an APM2 back when I first tried the All-in-One thing, and I couldn't get it to work.

Ideally, that is a superior way to go, as it bypasses one more component, so one less thing to fail.

I've got a 2.5 and I'm doing PPM in on it too.  I use PPM in on everything now.  No more 8-wire-inputs!

I did just see that FrSky is warning not to use more than 6 Channels on PPM input from the D4R-II.  They say something about if 8 channels are all at max simultaneously, there's not enough timing width to seperate the signals and something non-deterministic will happen.  It seems unlikely to get all 8 channels maxed out simultaneously, but I'm going to test this to see what happens.

Worst case, I'll have to just by the D8R Rx's and decase them instead.  Not a huge deal.

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Permalink Reply by Steven G on September 10, 2012 at 4:10pm

I have an APM 2.5 but it is missing the pull up resistor of Ch1. No response from 3DR as yet. Sooo, I would like to use the Ch5 approach but it does not work. Somewhere in the posts or forums some have said a trace must be cut as the two PPM pads are attached. Does anyone know what trace that is?

Thanks,

Steven

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DeveloperPermalink Reply by R_Lefebvre on September 10, 2012 at 6:33pm

Pullup resistor?  Are you sure that's not an internal one accessed in the code?  But there are no code differences between APM2 and APM2.5.

I have no idea about that trace.  It does sort of look like there's a trace between the two PPM pads on the back.  But I'm not sure, or know why, or what that would do.

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Permalink Reply by Steven G on September 15, 2012 at 2:51pm

R_L
I got a replacement APM 2.5 from 3DR and the APM1 CPPM method works. Of course the replacement has the Ch1 resistor.
Best,
Steven

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