R607FF / R607FS Modification

The Robbe / Futaba R607 receiver can be modified to output the PPM sum signal.

You can find a step-by-step tutorial to modify it here: http://pixhawk.ethz.ch/wiki/tutorial/receiver_sum_signal

The modification is slightly different than proposed in this wiki on the german page: ["R607FS"]

Please note that you have to invert channels 1-4 on the remote, like described here: http://pixhawk.ethz.ch/wiki/mav/transmitter#tutorials