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Topic: BRUSHLESS MOTOR SIMPLE CONTROL (Read 1 time) previous topic - next topic

rahulvyas

How do I control the BLDC motor, connected using RC with a arduino. like simply turning it on first of all?
Then after this, how to use the accelerometer data to turn on & of the BLDC motors?

-Rahul


spruce_m00se

brushless motor control is very complicated,
you have to pulse each of the three different wiring looms to get movement, and then you have to read the electromagnetic backfeed in each loom while off in order to get an idea of speed and timing required,

thats my underrstanding, i decided not to bother, and just bought some cheap ones,

a brushed speed controller is easy to make with an old servo and some transistors to beef up the power supply

Erni

#3
Aug 21, 2012, 05:55 pm Last Edit: Aug 21, 2012, 05:57 pm by Erni Reason: 1
You will need a Brushless Speed Controller for example:

http://www.hobbyking.com/hobbyking/store/__453__182__ESC_UBEC_VR-20_to_39_Amp.html

You can control the speed using the servo library (read DuaneB's blog)
The only hard part is the arming sequence, because it differs among the controllers

spruce_m00se

erni , what do you mean by arming sequence?

i misread this post, i thought that he wanted the make the ESC.
you need to know the amps used by the motor in order to choose a good esc. then read up on the esc and try to find one based on the atmega88 then you might be able to flash the firmware in the future for added funcionality

Erni

Quote
erni , what do you mean by arming sequence?


When you connect the battery to the ESC (and motor), the controller in the ESC goes through a process where among othher things it determins if it is safe to start the motor. While doing this it produces some tones using the motorwindings as a speaker. It ususally takes 1-2 secs. Some ESC's need full throttle during this sequence others no throttle and others combinations, that why it is the hard part.

In the old days (until last year I think) the Turnigy Plush ESC's used am Atmega8, processor but for somme reason they have changed that.

spruce_m00se

yeh thats true,
some of them need zero to start ,

if you start most of them with full, then go down to zero you can set the range and calibrate them to your controller,
so you are going to need to be careful you dont start them by mistake,

rahulvyas

Okay, I dont want to actually make an ESC , I have it & also have 4motors,which i used to make a quadcopter...(still working on it)..but I thought going from basics is something actually important...what say?


michinyon

Not a lot of point to re-inventing the wheel.

spruce_m00se

in my opinion its always important to understand the basics, as thats all i understand :)
i always try to work out what a code is doing before using it, or i try to make it do something else just to check i understand,

If you are making a cuad copter then im sure the code it comes with will work just fine, and understanding it might be too hard, i dont understand the cuadopters code, they are imense mindfields,

but basically, the esc uses a pulse of 1000us as zero throttle, 1500us as the mid point and 2000us as full, you cna get the servolibrary for arduino and experiment, the esc uses the same codes as a servo,

take the props off before experimenting though

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