Arming puts ESC into program mode

Archive
1

Hardware:
-Pixhawk4
-HobbyWing Skywalker 30A ESC

Situation:
I plug the lipo into the pixhawk, after everything has started up, the esc emits a continues beeping(i am pretty sure this indicates the esc is unarmed?). The pixhawk itself displays a sold blue light(indicating armed no gps lock) which doesn’t make sense since the safety button displays an unarmed state(4 rapid blinking flashes). Once I press the safety button in attempts to arm the system, the 4 rapid blinks change to double blinks (indicating system armed), but the esc begins to emit the beep sequence associated with being in program mode.

I have tried removing the pixhawk from the equation and plugging the esc directly into the rc receiver and everything works. The esc emits a continues beeping when the transmitter is turned off and once turned on the beeping stops and i am able to control the motor

hobbywing.com/uploadfiles/sx … 003ENG.pdf <- esc manual

Questions:

  1. why does the pixhawk show a solid blue light (indicating armed) but the safety button indicates not armed (4 quick flashes)?
  2. Why does the esc get put into program mode when i arm the system
2

I got my hands on an oscilloscope and i think i have found the problem. Bellow are the values of throttle output from both the reciever and pixhawk

                                         [u]Reciever[/u]                   [u]pixhawk[/u]

Pulse Width 0 throttle 1ms 1.35ms
Pulse Width full throttle 2ms 1.43ms
Period 22ms 20ms
Min Voltage -800mv -880mv
Max Voltage 2.5v 2.96v

I am pretty sure the issues is that the pixhawk is not outputting the correct pulse width. Not sure if the period makes a difference but i am pretty confident the pulse width is the culprit.

Question:

  1. Are there any params i can change in order to adjust the throttle pulse width?
3

@lufthansa747,
Are you sure that you have your receiver throttle input to the Pixhawk mapped (RCMAP_X) to the correct servo output?
Regards,
TCIII GM

4

Yes i had to re-map the throttle to channel 1.

After some more investigations i found the the values i posted above for the pixhawk are for when its in flight mode FBW. When in manual mode the pulse width is 1ms and changing the throttle stick doesnt change the pulse width. each flight mode seems to change the throttle pulse width differently.

Why is this the case and how do i know what the correct throttle pulse widths should be for each flight mode?

Why does manual mode take away all throttle control?