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Candas1 edited this page Jan 28, 2022 · 24 revisions

This variant can be used with PPM-SUM RC Receivers.
As opposed to PWM, it will send all channels on a single wire one after the other.

Configuration/Parameters

CONTROL_PPM_RIGHT is for the right sensor cable and is set by default to limit the noise as this cable is shorter.
You can use CONTROL_PPM_LEFT instead if you need to use the left sensor cable.
DEBUG_SERIAL will be automatically enabled on the opposite cable.
PPM_NUM_CHANNELS is the number of channels for PPM and is 6 by default. As an example Flysky fs-i6ab receiver is sending 8 channels even when used with a 6 channel transmitter

Wiring:

  • Connect PPM port of your receiver to green wire on right sensor cable(shorter)
  • PPM is highly prone to noise : keep cables short, use 100nf capacitors, use shielded cable, use ferrites, stabilize voltage

⚠ Red wire from sensor cable delivers 15v !!! Use 3.3v from programming port, 5v from hall sensor cable, or a voltage regulator.

Transmitter configuration:

  • Enable PPM
  • Assign desired joystick to channel 1(steering) and channel 2(throttle)

Calibration:

Proceed with calibration for better control.

Troubleshooting:

If the board is beeping

  • Check the number of channels, even if you transmitter only handles 6 channels, you receiver might transmit more channels
  • Make sure you enabled PPM on your transmitter
  • Make sure you use the PPM port on your receiver
  • Make sure you are using the sensor cable(left=CONTROL_PPM_LEFT or right=CONTROL_PPM_RIGHT) selected in config.h
  • On some boards the wire colors might differ, try the blue wire
  • You might have a defective input, because of a fried resistor or MCU pin (e.g. issue), you can configure the firmware to work on the other cable