As a follow-up on my previous post on the Futaba FF9 trainer interface, I’m reporting the measurements of my E-Sky “0404” remote.

The E-Sky uses a much more popular 4-pin miniDIN connector:

Pin numbering is left-to-right, bottom-to-top: left-bottom is 1; right-bottom is 2; left-top is 3; right-top is 4; shield is all around.

Using the described pin-numbering, I measured the following signals:

  • pin 1 – shield: negative modulated PPM. Mostly high (1.7V), shorter pulses low (0V)
  • pin 2: high impedance/not connected
  • pin 3 – shield: 4V DC; probably used for remote power to the slave
  • pin 4: low impedance, no signal; probably PPM input when in master mode