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Topic: ESC weird behavior (Read 483 times) previous topic - next topic

ogfire88

Hey everyone, I am new to arduino. I have this esc:
http://www.hobbyking.com/hobbyking/store/__6460__Hobbyking_SS_Series_25_30A_ESC.html

this motor:
http://www.hobbyking.com/hobbyking/store/__6246__hexTronik_DT700_Brushless_Outrunner_700kv.html

and am running them on a computer power supply the same way this guy is doing it
http://www.instructables.com/id/Homemade-table-tennis-robot/

I have ran the motors on my RC transmitter and reciever great. I get great throttle resolution. I can run them pretty slow and ramp them up however I'd like. When I use the arduino (servo library) they start up way too quick. I am making a table tennis robot similar to the one in the video and the speed they ramp up to wouldnt work in my application. any ideas? the ESC's dont even start the motors until the servo write command gets to around 80. Thanks for the help.

MarkT

You know you can provide finer resolution to Servo.write() by passing a number of microseconds (range 850 to 2500 I believe) rather
than a number of degrees (0..180)?
[ I won't respond to messages, use the forum please ]

DuaneB

Hi,

Its possible that your transmitter is sending a signal in the range 1000-2000us, starting at 1000 but the servo library defaults to 1500us meaning you ESC will be driven with a reasonable amount of power when you might have assumed it was at rest.

Two suggestions -

1) check the range your receiver sends using this -
http://rcarduino.blogspot.com/2012/01/how-to-read-rc-receiver-with.html

2) Adjust the range of your outputs based on 1) above and using servo.writeMircoseconds instead of servo.write

Duane B

rcarduino.blogspot.com
Read this
http://rcarduino.blogspot.com/2012/04/servo-problems-with-arduino-part-1.html
then watch this
http://rcarduino.blogspot.com/2012/04/servo-problems-part-2-demonstration.html

Rcarduino.blogspot.com

ogfire88

Thanks guys. I ran the writeMicroseconds and it does exactly what I want. Nice resolution and it can hold steady at fairly slow speeds. I definitely appreciate the help!

MarkT

Glad to hear its working now :)
[ I won't respond to messages, use the forum please ]

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