IRIS - won't arm - no radio?

I have spent 3 hours trying to get the new IRIS to arm… without luck. The sequence is simple and all appears to be fine until the arm with the rudder right, which just does not work. Here is what I do:

TX on (switched in stabilise mode), plug in battery, tune plays, press top button, goes solid red+tune, (wait for fix) green flashing LED. Hold throttle bottom right (for 30sec) nothing, no arming no throttle …

In mission planner (USB connection) the virtual horizon shows correctly, but the radio calibration shows no green bars at all. Terminal -> radio shows zero for all channels. It looks to me like the receiver isn’t working or is not bound. No instructions mention binding RX, and I don’t want to start dismantling the case it in case it is something serious that needs replacing.

What do you suggest? I have had no problems with many APM2.6 in fixed wing and quads, but havn’t had a PX4 before. Is there something obvious I have missed?. I cant find anything on the forums and I thought the IRIS was supposed to be ready to go out of the box.


The fact that the green bars on the radio calibration screen dont move when you move the sticks on the TX makes me thing that the RX is not bound properly. My suggestion would be to first open up the top shell and check if there is a green light :green_book: on the RX. If not then you should try to bind it. If you find that it still does not work when you see a green LED on the receiver then there could be a hardware fault on the IRIS.

Bind IRIS receiver

The first thing you will need to do is remove the top shell from the IRIS.

Disconnect the battery from IRIS, and turn off the transmitter. Ensure that both the on/off switches on the back of the transmitter are set in the down position. Now hold down the F/S button on the back of the transmitter, and turn the transmitter on while holding down the button.

Hold down the F/S button on the receiver inside the top shell, and connect the battery to IRIS while holding down the button.

Disconnect the battery from IRIS, and turn off the transmitter. Then turn on the transmitter and re-connect the battery. You should see a green light :green_apple: on the receiver indicating that it is connected to the transmitter. If so, replace the top shell, and reattempt the preflight steps.

Im a novice at this,

what could be the cause if the led light stays red?

thanks in advance