mcfg.rssi_aux_channel over pwm input if PPM is enabled

[KipK]

This is more a feature request than an issue.
the mcfg.rssi_aux_channel only works for a ppm channel if PPM is enabled. We can't use channel 2 as pwm input ( this ones remains free to use ) for frsky rssi.

It only works if we use PWM input for radio channels( feature PPM not set ).

[didgydont]

any news on this ?

[kiteretro]

Just want to chime in with this request... something like using the RX pin 2 for this, I'm pretty sure this is the only unused one in that area that isn't GPS serial, or the softserials?

[hydra]

that's correct. RC3/4 are GPS, RC5-8 are softserial.
What kinds of RSSI input do you need? There's a few i'm aware of, PWM RSSI, Analog RSSI, any more?

[vbabich]

Frsky PWM RSSI input would be nice, duty cycle 1%-99% iirc

[KipK]

channel 2 can already be used for pwm rssi reading if radio input use separated channels.
The actual problem is it just doesn't work if ppm is enabled.

[hydra]

ok, there's a few things that would need to change then.

1. the pwm mapping code, see pwmInit
2. the storage of the rssi value after the irq handler reads the value - if it was enabled then the data would be overwritten by the ppm irq handler - see 'captures' variable an ppm/pwm callback handlers
3. the code that extracts the RSSI value from rcData.

it seems that any solution that involves that code would be somewhat cumbersome or hacky. I would suggest splitting the mapping code from the PPM code and the PWM code and then adding PWM RSSI as a seperate feature or perhaps extracting what you need from the existing code and adding it as a seperate feature.

[hydra]

also, i think timecop has some new pwm code, according to commit b7fce19

[trollcop]

Feel free to fuck off and stop spamming my project.

[carballada]

Sorry, but I don't understand, this feature or change will be available soon? still is open

[trollcop]

Feel free to contribute code that makes it work.

[carballada]

@trollcop, yes, you are right, sorry if you feel like I demand something and if I am not able to contribute, was not my intention, only was a problem with my low language skills

[xeno010]

The problem is, the FrSky PWM-RSSI singal is to fast.
e.g. D4R-II use a ~110 kHz PWM singal.

The best way is to use an RC-filter (convert a PWM in a analog singal (0-3.3V))
See #165 for more infos.