Kindly Requesting Guidance on Kill Switch Configuration for VTOL UAV

ArduPlane Plane 4.4
1

Hello,

We are currently developing a VTOL UAV powered by a gasoline engine and would like to ask for your assistance regarding the ICE parameters.

Our goal is to connect a kill switch, which is linked to the ignition, to the flight controller (FC), so that the FC can control the kill switch ON/OFF. Ultimately, we aim to have the kill switch turn OFF automatically just before landing during autonomous flight.

The issue we are facing is that the kill switch does not turn ON when it is connected to the FC, even though we have set the parameters according to the manual. However, when we connect the kill switch directly to the RC receiver, it does turn ON, so it seems the problem is not with the kill switch itself.

We would sincerely appreciate it if you could take a moment to review the following product and parameter details and provide any guidance you can.

Product Information:
Kill Switch: RCEXL Opto Gas Kill Engine Switch Version 2.0 ( RCEXL Opto Gas Kill Engine Switch Version 2.0 - Ultimate Guide)
Ignition: Desert Aircraft Ignition Module ( Desert Aircraft Ignition Module|DA Engine Components|Desert Aircraft Australia)

Parameter Information:
ICE_ENABLE: 1
ICE_START_CHAN: 6 (Channel 6 is also used on the transmitter.)
ICE_STARTCHN_MIN: 0
SERVO6_FUNCTION: 56[RCIN6] (Kill switch is connected to the FC’s Servo 6.)
ICE_PWM_IGN_OFF: 1100
ICE_PWM_IGN_ON: 1800
(The reason for modifying ICE_PWM_IGN is that my transmitter’s PWM range is only from 1066 to 1933.)
ICE_PWM_STRT_OFF: 1000
ICE_PWM_STRT_ON: 2000

2

Update to 4.6.x.
RCin range doesn’t matter as long as it enters LOW/HIGH switch range. You need to be armed to start the engine.

3

Thank you very much for your response.

As you suggested, I upgraded to version 4.6 and tested it, but unfortunately, the ignition kill switch still does not activate.

I have one question I’d like to ask. Should the ignition kill switch be connected to the flight controller (FC), or to the RC receiver?
I’m wondering if the DO_ENGINE_CONTROL mission command would work even when the ignition kill switch is connected to the receiver instead of the FC.

For reference, I’m using the CubePilot Cube Orange FC and a FUTABA T14SG transmitter.
Currently, both the RC receiver and the ignition kill switch are connected to the FC.

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20250627_1637151920×2560 561 KB

Originally, I had the ignition kill switch connected directly to the receiver on channel 6, and I manually toggled it ON/OFF using the transmitter.

Below are the parameters I’m using with firmware version 4.6:
ICE_ENABLE = 1
SERVO6_FUNCTION = 56 (RCIN6)
RC6_OPTION = 179 (ICEngine start/stop)

4

RCINx is raw (channel mapped) passthrough from RC to servo output.
Everything should be connected to the flight controller.