Throttle output timing at boot

[St7ven]

Hi,

I’m using a Matek WSE with an esc hobbywing pro opto.

My issue is the following:

1. When I plugged the battery, the ESC will do the three bip at power up, then it will never do the bip that confirm the self test.
2. When I plugged the battery, but the flight controller is already powered through USB, the ESC will do the three bip at power up, then it will do the bip that confirm the self test.

In case 1. I can arm but the motor won’t spin
In case 2. I can arm and the motor spin

I suspect a timing issue with the ESC powered and the PWM signal coming out the flight controller. In fact, the ESC has an USB mode.

I tried this without success :

Min_pwm output to the esc right after boot possible?

As far as I know, the only way to do what you want is to ignore the safety switch for the motor channels. One way to do this is to simply disable the safety switch with BRD_SAFETYENABLE = 0, as you have already found. Another option is BRD_SAFETY_MASK (http://ardupilot.org/copter/docs/parameters.html#brd-safety-mask-channels-to-which-ignore-the-safety-switch-state), which will allow you to define which channels will ignore the safety switch. For a quad (channels 1-4), I think it should be BRD_S…

I’m looking for some help or guidance to solve this issue.

Thank you

[geofrancis (GeoMuir)]

How are you powering the flight controller?

[St7ven]

In case 1., It’s powered with the battery.
In case 2. It’s first powered with the USB C, then the battery.

For now, the workaround for case 1, it’s to delay esc supply by manually disconnecting it from the battery supply, and reconnecting the esc after the flight controller boot up.

It really sound like a delay or init issue on the pwm controlling the esc.

[geofrancis (GeoMuir)]

It sounds like some kind of issue with the escs, what output mode are you using? Pwm? Dshot ?oneshot?

[St7ven]

I use PWM. The ESC is USB compatible as well

It would be nice to have a way of having PWM right at start.

[geofrancis (GeoMuir)]

I suspect this is an esc firmware issue rather than an ardupilot problem.

Does the esc work if you plug it into a servo tester or receiver after its started up? Replacate case 1 by plugging the ESC into a receiver or servo tester a few seconds later.

[St7ven]

Currently, it will be complicated for me to unsolder the esc and test with a servo tester.
But I agree that it could be an esc fw issue.

Nonetheless, a nice work around would be to have the FC providing a PWM at power up. Is that possible?

[geofrancis (GeoMuir)]

it outputs pwm as soon as it starts up but that takes a few seconds.

I just checked and those ESCS came out almost 10 years ago.

[St7ven]

You get it right! Time flies.

The ESC worked like a charm. I think I can recall using it with another FC in the past.

Thank you for the information about the timing and your support.