Controlling Brushless motor using Pic

[alexix]

I'm trying to controll a brushless motor using dsPic30F4012

Does anyone know or have a tutorial easy to understand about both hardware connections between the pic and the motor's driver and the software?

 

[Wp100]

Hi,

Loads of examples on the web, though most are using the simpler 16F range of chips not a dspic which has very little coverage.
Here is a good place to start https://ww1.microchip.com/downloads/en/AppNotes/00905a.pdf

Depending on the size of motor you can use a mosfet or ordinary transistor to turn the motor with the pics PWM output signal.

 

[5uco]

I'm trying to controll a brushless motor using dsPic30F4012

Does anyone know or have a tutorial easy to understand about both hardware connections between the pic and the motor's driver and the software?

This may have some relevant info:

**broken link removed**

D.

 

[asmo]

May be this :
**broken link removed**

If you need dsPIC33EP512MU810 board or plug-in let me know..

 

[alexix]

Thanks everyone for the helpful links.

the hardware schematics from AN957 are hard for me to understand, I already have a ESC for my motor, should that be the 'MOSFET Driver Circuit' from 5uco's link? if so, my ESC only has 3 wires that require connectivity to MCU (which I assumed are GND,VCC and a pwm) but I see from that schematic that that driver takes all pwm outputs, how?

 

[5uco]

So, you have an ESC ??

It probably has the drivers and the other circuitry in it.

Somewhat baffled now. OK. Lets go back ..

Do you have a 3-wire BDLC Motor. If so your ESC should have 3 fairly large wires to connect to that. Colours vary ...

On one of my BDLC controllers There are 5 connections in total :

DC +ve IN [ Red ]
DC -ve IN [ Black ]
The 3 connections to the motor. [ In my case, Yellow / Blue / Green ]
Control In ( this is the slider of a 2k linear pot. From 0V to 5V / 12VDC )

This is all it needs, the 18V DC Input goes to a 7805 regulator and then 5V to the pot. This controls the speed.

So, I'm not sure now where the dS pic comes into the picture? Unless you have one of the ESC's intended for Radio Control Models in which case I think [ ?? ] they may take a PWM 'servo' input. Not sure, mine was a DC level as I said.

D.

 

[alexix]

My "Control In" has 3 wires, as shown in this picture: img

When I started documenting I stumbled upon hard schematics and I thought I need to implement them too even with ESC. The purpose of the dSPic is to control the speed of the motor based on some algorithms, but for now I'm just trying to start it.

So I guess I just connect the 3-pin cable to PWM,GND,5v? does it matter if its PwmLow or PwmHigh?

 

[dr pepper]

I get it.
You need to get your pic to output a servo compatible pwm pulse, from memory its a 50hz based pwm with 2msec to 2.5msec pwm width.
In other words the pic needs to act like the o/p of an rc servo, thats what the esc looks for.
There are lots of examples on the net for controlling a servo from a pic.

 

[5uco]

Dr. P. Yes! Looks like a standard servo connector ...

Alex : Did find this on the Hobbyking site, after a lot of faffing ....

https://www.hobbyking.com/hobbyking/store/uploads/492127986X314475X42.pdf

Unfortunately not very good at the spec. on the PWM in but Dr. Pepper is right.

I have a normal servo [ Hi-Tech something or other ], and that works thus:

Frame rate 20mS
Pulse length 0.5 mS full Anticlock.
Pulse length 1.5 mS Centred.
Pulse length 2.5mS Full Clockwise.

They do vary somewhat, but that servo is 'not top of the range' but then neither am I ...

You should be able to verify this with Hobbyking I would think.

D.

 

[alexix]

Thank you all, its clear now

 

[dr pepper]

Excellent!

Yes about the variations, I found that a particular cheap brand of servo tried to burn itself out when you applied a pwm below or above its control range, ie the servo tried to go past its endstop.
All down to quality I spose.