In the latest code there are separate .pde files for each motor configuration. If you're up to the task, you can make an Octo easily by following the patterns already set. Check out APM_RC for the correct pins for the 7th and 8th motor. Send me the code when your done.
Any news on the Octo??
Is it necessary to use PL3, PB5 or PE3 pins ? or is it possible to use side connector PWM outputs 5 and 6 ?
Could be simpler to use side connector PWM outputs 5 and 6, and if needed use PL3, PB5 or PE3 pins for camera or other needs.
In the ArduPirates code for Octo's, we started using PE3 and PB5, but PE3 doesn't last long, after a few tests, it stopped working, so we switched to PL3, and it is working fine.