Does anybody know how how to use the PPM encoder input on 2.5? Does it use the old APM1 method (jumper between input 2 and 3, PPM into input 1)? Or does it use the "APM2 method" (solder jumper on the backside, PPM input into input 5?) which never actually worked, so the APM1 method was the real way.
So is APM2.5 using the never-used APM2 method, or still using the old APM1 method?
I see it still has those PPM/Ch5 solder jumper pads on the backside.
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.
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.
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?
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.
I got a replacement APM 2.5 from 3DR and the APM1 CPPM method works. Of course the replacement has the Ch1 resistor.