APM Rover Output Relay

ArduRover
1

As stated in the documentation http://ardupilot.org/copter/docs/common-relay.html

“A “Relay” is an digital output pin on the APM or Pixhawk that can be
switched between 0 volts and either 3.3V (Pixhawk) or 5V (APM2).
Similar to a servo it allows the flight controller to invoke some action
from another device on the vehicle. In Copter, Plane and Rover, up to 4
pins can be defined as relays.”

“On the APM2, A9 (pin 9) is the pin that is recommended to be used as a
relay. In fact any of the pins from A0 ~ A8 may also be used as relays
but to use these you must manually set the RELAY_PIN parameter (to “0”
~ “8”) through the Mission Planner’s full parameter list.”

“On Copter 3.2 (and higher) the “First” relay can be controlled with the
Ch7/Ch8 switches.”

How do I enable ch7 to controls the relay on rover?

Any suggestions?

2

@agreear,
If I remember correctly, the Ch7 input on the Rover is used for recording waypoints and the Ch8 input on the Rover is used for the Flight Modes. Therefore the Ch7/Ch8 outputs may not be available for relay control. That is why you should use the Analog pins for relay control.
Regards,
TCIII AVD

3

Ok that’s a bummer. I’ll have to find another way to toggle the relay. Thank you.

4

I “think” if you have CH7_OPTION set to 0 then CH7 its still available for relay control.

If you have an APM set RELAY_PIN to 7 via the full parameter list and give it a go. Note I haven’t tried this.

You might have to set RC7_FUNCTION to 1 which is RCPassThru.

Thanks, Grant.

5

The problem is when I hook up the songle 8ch relay board to Output ch7 on the APM that the relay comes on when I plug it in and does not turn off.

the toggling of the ch7 switch does not turn it off. the ch7 low of 1000 needs to be 0 for this to work correctly. it is currently set at 1000 rc7 min and will not accept 0 as a min, which is out of range. the relay board is NPN so I changed the RELAY_DEFAULT to 1 to operate correctly.

The APM Output needs to act like the RELAY_PIN set to 13, aka APM analog pin 9. This is not possible through the rover software. It would be nice if the developers added this feature in some way or fashion.

Thanks for the suggestion though.