The (should be) very simple act of turning a relay on

Can anyone point me towards another source of arduplane documentation .
I’m sick of looking at examples from 10 software revisions ago , talking about commands that no longer exist !
Cannot trigger camera with matek f405 wing . Untold hours of absolute frustration trying
to make sense of really , really poorly written and out of date documentation .

I’ve gotten it to work before although that plane sits at the bottom of quabog river …
thanks to documentation which left out the fact roll and pitch limits are ignored in STABILIZE mode .

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So, we’re just trying to click the shutter on a camera with one of the relays right?

What’s your current setup and parameters like? Maybe I can help out

Matek F405 wing . CRSF radio . I hacked the trigger switch on a runcam split 3 micro camera . Basically I’m using a relay to close the connection the same way when I press the button manually .
CH7 ( camera trigger ) CAM_TRIGG_TYPE =1 (relay)
RC7_OPTION = 9 ( camera trigger)
optional hardware / camera gimble SHUTTER = SERVO7
BRD_PWM_COUNT=10 ( default , no GPIO defined)
RELAY_PIN= 56 ( according to matek )

I believe the trouble is with the relay pin definition . The documentation uses PIXHAWK as an example . Matek runs completely different !

This is a AR900mm wing . simple two elevons and a throttle . All the control surfaces
are working fine ( in both STABILIZE and MANUAL modes )

You have a conflict. Your CAM_TRIG_TYPE is relay but RC7 is motor output 7. Is your relay connected to main output 7? Your BRD_PWM_COUNT is not germain because it controls the aux outputs starting at aux 9 but the setting 10 is setting the first 10 outputs to PWM not digital relay/on-off.

I don’t know the Matek so I am not sure about the RELAY_PIN parameter.

Remember everything here is done by volunteers and if one of us does not do the documentation it doesn’t get done.


Thanks for the reply . If I ever get to the point where I can volunteer to improve documentation in a meaningful

way , I’ll consider it .

All else aside Ardupilot appears to be the most capable of the platforms

But … the price of admission is much higher . Not in dollars either . Basically there are people out here who really want to use this .



Try setting the brd_pwm_count to 6 to allow 7-10 to be configured as gpio. 10 is the default value from the hwdef file. Review this file for useful config info

Note: All outputs on this board are “aux” in a sense because it doesn’t have an iomcu with “main” outputs.

Am I correct in assuming the Matek F405 wing FC uses an “abbreviated”

firmware due to the 1 MB memory limitation ? If so am I correct in assuming

that RunCam support is not available for this reason ?

If I were to use Matek F765 with it’s 2MB memory and a full featured firmware ,

could I simply control runcam with UART ? I don’t need every single function to be available , just

camera trigger .

RC, I was not chastising you to volunteer, just a reminder that there is no one paid to write documentation so it does not always stay current, even if it gets frustrating some times.
Yes the learning curve can be steep but the flexibility is unmatched.

That’s what the Wiki says. Personally I wouldn’t buy a new Flight Controller unless it was an H7 (H743-Wing for you) but yes the Matek F765 has 2mb.

BTW-I don’t know about controlling the Runcam.

Where is your PR adding a note to the documentation for that mode?

Given Copter’s stabilize obviously does do that, a … note: is
definitely in order.

Problem solved . The issue was with “RELAY_PIN” settings . The examples for pixhawk will steer you in the wrong direction

when using the MATEK F405 wing .

also I get some weird issues with “CAM_TRIGG_TYPE” settings reverting back to their previous settings even though parameters saved

and FC reboot . It needs to be set to “relay” and not “servo” .

But yes it works . The signal line goes +3.3v for about a second ( or whatever its set to ) then back off .

BRD_PWM_COUNT set to 9 .

I’m using the LED pins (GPIO 59) to do the switching , leaving all my servo channels available .

RC9_OPTIONS = 10 (camera trigger)

in optional hardware screen set shutter type to SERVO7 ( sending the switch command over RC channel 7)

SERVO7_OPTIONS = (camera trigger)

Glad you figured it out. In Ardupilot speak “SERVO” means PWM and Relay means digital output.

BRD_PWM_COUNT =9 Makes the first 9 aux ports PWM not digital.

hello again

Im trying to go out and fly but I’m getting these cryptic EKF prearm check alarms . Velocity_horiz off , position_horiz off and a couple others .

The problem is when I search for what these terms mean I get nothing .

This doesnt happen all the time . Not knowing what these terms mean , means I can’t fix anything .

Basically where are the definitions for all the terms seen in the EKF status window ?

Any help would be greatly appreciated

R Champagne

This is usually an insufficient GPS fix. Do they go away when you see these messages?
EKF3 IMU1 is using GPS
EKF3 IMU0 is using GPS

It could be EKF2 and there could only be one depending on the actual FC.

You should add (Solved) to the title of this thread and post a new one for this question. Best for all looking for help in the future.