RFD900x only - no transmitter

[goaround (Rob)]

Hi everyone, first time posting and no doubt lots to come.

Current setup is a H743 with RFD900x telemetry radios.

I would like to be able to complete a short flight completely autonomously, auto take off and land with a few waypoints in between.

I have searched on this forum as well as more broadly, is it possible to setup and fly without a regular transmitter? I would like to be able to load mission plan via telemetry radio or usb and then complete a short flight.

Has anyone does this before or have any advice about how I might go about it? Thanks in advancd.

[geofrancis (GeoMuir)]

You need a transmitter to set up the vehicle but once its setup and tested you can fly without one.

Ardupilot is NOT designed to autonomously fly a newly built aircraft in auto mode it needs tuned or bad things will happen.

[goaround (Rob)]

Thanks geofrancis, really helpful information. That got me looking further into the flight modes and what they actually do.

With a requirement to have autotune run for efficient flight and to allow full control rates and as you said a neccesity.

Plan now will be to either arm from MP or shake to wake with a joystick via usb that will be able to switch between auto, autotune and probably RTL mode and fly the aircraft through an autotune cycle and utilise the rfd900 as the data carrier.

Appreciate the insight, cheers.

[xfacta (Shawn)]

You need conventional RC control at least for set up and tuning, and most people would say even when running Auto missions in case you need to take control.
You will need a 3 position switch with Stabilize, AltHold and Loiter.
You will need to practice control on Stabilise mode as you will need this mode if something goes wrong.

After the craft is flying well in all modes and situations you can more safely run Auto missions.

[anon53993083]

to make things easier you can create a rc link on your rfd900x on the ground side then use the gpio1 pin to port that rc signal back to the flight controller on the air side easy setup and only require an additional 2 wire connection on the flight controller side while keeping the rc link close to the radio at all times.

RFD900X PPM Pass through test

Made simple test today by plugging trainer wire from transmitter, which outputs 3 volts PPM, directly to pin 15 of RFD900X. And connect pin 15 of air unit directly to RCIN pin on PH2.1 controlling 6 servos. Result: it worked as expected. However, I felt a slightly more latency compared to normal receiver. It just didn’t feel as smooth. Different radio set up might improve latency. This test is done with default settings except transmission power (100mW) IMO This setup should be fine for …

Telemetry with PPM?

I haven’t figured out the voltage my transmitter outputs from its trainer port (DEVO 12S) Haven’t got a chance to use an oscilloscope yet.

[goaround (Rob)]

Just to follow up, I havent had much time to spend on thsi project but just thought I would share where I got too. Thank you for the previous comments too btw.

I managed to use the rfd900x and a control pad, logitech 310, to clget control of all of the servos and the motor.

A few issues to sort out yet, like the motor spinning up on disarm but progress is happening.