control of hobby brushless motor ESC using servopos

[macrobeak]

I have been experimenting with controlling brushless motor ESC (electronic speed controllers) using PICAXE via the servopos command.
My results have been erratic.
Sometimes the ESC does not recognise the servopos signal for part of the range (error message via beep code).
Other ESC's only operate over a very small part of the servopos signal range.
I have experimented with single direction and forward/reverse ESC's.
I have tried to calibrate them to the servopos range using the operating procedures.
I have had good success when using servopos for straightforward servo control.
Does anyone have any experience or ideas out there?
My ultimate aim is to control a brushless motor smoothly over forward and reverse ranges, but even control in the forward direction only would do fine for now!
Thanks in advance for any knowledge!

 

[Goeytex]

Welcome,

You have not given us very much to work with.

You might start by posting a link to the datasheet of the ESC in question. We also need to see your Picaxe Basic code and a complete circuit diagram including the Picaxe, ESC, power supply(s) and any other other components. Without these, about all anyone can do us guess.

The Picaxe Servo output is compliant with the servo signal requirements of almost all hobby type servos including both either analog or digital so I doubt the problem is with the servo command. The servo output is stable as long as there are no commands in the program that use the timer.

 

[srnet]

And a lot of ESCs are very fussy about the kind of servo pulse they get on power up, for the obvious reasons of safety, you dont want the motor going off full throttle when you power up the radio (and servo pulse).

You would need to consult the manual for the ESC as to the specific power up requirements, it varies from one model of ESC to another.