Relay triggering from rc joystick and rcmap questions

Project is a Bait boat (takes bait out to a specified position where it releases a hook the open the door to let bait out)

The controller is std LHS throttle, ive added a spring to centre the left stick though. Skid steer was moved to the left stick for both throttle and steering by swapping 3 and 2 in the RCMAP.

works great in manual. navigate fine range is goo all is good.

Now… the final things too add are as follows.

LIGHTS (plain on off with be great)

HOOK release: want the on forward movement of the LSH stick (CH3)

Bait release: want that on left movement of the RSH stick.

SW-A set to record WP
SW-B arm
SW-C 3/6 modes
SW-D mixed to SW C to provide all 6


I can get the relays to trigger… and i cant assign CH4 or CH3 to trigger those even if i could looking at the info … Channels 7 and 8 are already used for record WP and arm.

any ideas anyone?

I think your right that 1 - 4 outputs are pwm only. Why not use outputs 5 and 6 or if the flight controller is a pixhawk 9 - 14

CH5 and 6 are used to mix two switches together on the handset to deliver my 6 modes :confused:

I think i need the output to come from and aux channel so its a solid 5V and not a signal output though. little confused as i say …

you can set up the outputs of 5 and 6 om the flight control to be inputs from other channels on the transmitter


that sounds like it should work… where in the parameters are those settings do you know?

SERVOx_FUNCTION should do it. You can set the outputs to respond to CH3 or 4. But that is for a pwm signal though.

sorry but that got me nowhere :confused: im really getting confused now and starting to forget where i started at… just to recap and so i have it down for my own memory

SW-A set to record WP (CH7)
SW-B arm (CH8)
SW-C 3/6 modes (CH5)
SW-D mixed to SW C to provide all 6 (CH6)
VAR-A=CH9 would like to have this powering the light but i CANNOT get a signal to show up at all in the radio calibration and the servo list only goes to 8
CH2 and CH3 have been switched in the parameters to get all movement control onto the LHS
leaving me channels 3 and 4 with which to control the two relays which for the life of me i cannot seem to work out how to do.

not that it really matters at the moment CANNOT get my damn relays to work bench tested anyway.

dont suppose you know anything about these things do you? if triggering 12V solenoids.


the left hand terminals are NO … it feeding power through a separate UBEC to the DC+ and DC-

if i feed the CH connection a +5v the light on the relay block comes on but the connection does not switch to NC … if i feed the CH connection an earth again the light comes on and i still get no state change. whatever i do i cannot get those relays to change to NC

any and all help appreciated even if its to point out how silly i am for missing something.

I don’t really have any experience using relays yet.

Although this is a bit expensive it will use a pwm signal to turn on the relay.

Or this.

The attached will configure relay outputs on AUX 1&2 (Pixhawk) from RC input channels 3&4 respectively. That will put 3.3V on these outputs which no doubt will not work with those relays.

Or this :grinning:

A pair of those switches look like a very easy solution to powering 5v to the relays. i think ill go for that option.

Many thanks to everyone for their replies.

had a test run at the weekend and everything looking good in relation to steering and handling in manual. Now i have to get my head round how to log things and view the logs too :confused:

Those are relays. If 10A/30V is sufficient you don’t need anything else.

I was reffering to the reciever controlled switches. i can use those to deliver 5v to the coil on my relays to switch the 12v cant i?

Those PWM switches ARE relays. You can switch the load directly with them if its withing the 10A.30V spec. What do you need the other relays for? I mean you could switch the coils of one relay with another but what’s the point unless the PWM switch’s can’t handle the load.

Also, do you have a spec sheet for those relays? Not all solid state relays will switch DC loads.

I did not notice that at first glance, the switches i have on my bench are not switches per-se they deliver a constant 5v …

the load is well withing that range the draw for the solenoids is 0.6A so even with a pair in parallel i’m good.

ill go have a better look at them see if they latch or are momentary. opperation will need to be momentary.

once again… thank you :slight_smile:

I think the relay contact is just a SPST with contact ON with PWM>1800us and contact OFF somewhere a bit <1800us (assuming some deadband). I’m not actually sure of the PWM threshold level but it’s likely to be in this range.

worth a go then i think… ill order a pair :slight_smile: im sure ill find a use for them. if they latch i imagine i can get round that with a curve?