Relay will turn on, but not off

ArduCopter
1

Hi all,
hoping someone can shed some light on this.

I’m being driven mad trying to get the landing lights on my new build operational.

Using a Cube Orange+; trying to switch Servo8 (used to drive some LEDs via a transistor), controlled from a switch on RC channel 6.

Configuration looks like this:

SERVO8_FUNCTION: -1 (GPIO)

RELAY1_DEFAULT: 0 (Off)
RELAY1_FUNCTION: 1 (Relay)
RELAY1_PIN: 108 (MainOut8)

Rx supplying RC6 is sending Low @ 1062 and High @ 1937 - well outside the 1200/1800 margins.

RC6_OPTION: 28 (Relay1 On/Off)
RC6_MIN: 1062
RC6_MAX: 1937
RC6_TRIM: 1500
RC6_DZ: 50
RC6_REVERSED: 0 (Normal)

Symptom: When the system is powered up, the lights are off (correct).
Flipping the switch on the transmitter turns them ON.
Flipping it back again - no effect! - they won’t turn off.

This isn’t anything to do with the electronics - decoupling from the lights and just measuring the voltage directly on pin #8… it correctly starts out at 0V; transitions to 3.3V; but never transitions back to 0 again.

Nor is it the transmitter - MissionPlanner’s showing the expected values as the switch is toggled.

Any clues deeply appreciated!
cheers, John

2

Could you post a schematic of your “LED controller”?

3

Attached, if you’re interested :slight_smile:
But unfortunately it’s not the problem - with it unplugged, the behaviour of pin #8 is still wrong.
Blasted thing happily transitions from 0 => 3.3V when the switch is flipped ON; but not back again when the switch is turned OFF.
landling_light_schematic

4

Out of curiosity what does the Banner message say about how the outputs are configured on the messages screen after connection?
One like this:
26-Feb-24 03:24:53 PM : RCOut: PWM:1-14

Which BTW is a Cube Orange+ with Servo8 configured for GPIO. Suggest you use an Aux output.

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5

when you toggle the relay from mission planner does it switch off? It will show if its an input or output issue.

MP_relay_control
MP_relay_control588×850 291 KB

relay 0 = relay 1

6

Hi Dave,
I’m seeing exactly that message:

messages_small
messages_small850×455 14.1 KB

ps. You’ll have to educate me - what’s its significance? Is it thinking that RC8 is still PWM as opposed to GPIO?

7

And on the Servo/Relay side of things… everything’s greyed out; attempts to use the High or Low button produce an error; the Toggle button does nothing:

servos_relays_small
servos_relays_small943×457 56.7 KB

8

Yep. Use an aux port. IOMCU are PWM (or DSHOT in very recent releases) only.

Also, Mission Planner confusingly labels RELAY1 as Relay0.

9

Yes. Try using an Aux output not the main outputs.

10

You guys are going on my Christmas card list - OUTSTANDING - THANK YOU!!!
Five minutes’ work to split off the signal wire - and success. Woot!!!

split_off
split_off800×450 39.6 KB

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