PDA

View Full Version : Brushless motor control



Remington Baker
03-24-2010, 04:22 AM
I want to use a BS2 to controll a sensored brushless motor. I need to read 3 hall efect sensors in the motor and and use a lookup table to match that 3 bit number to a 6 bit output number to drive each phase high low or neutral. I can use lookup and lookdown for the table but how do I asign these numbers to pins for parallel input and output.

Mikerocontroller
03-24-2010, 04:46 AM
Check out the dedicated INS, OUTS and DIRS registers in the BS2 RAM memory. You can address different combinations of pins and read their state or set their condition. There is an explanation of these registers and their variable names at the beginning of Chapter Four of the Basic Stamp Syntax and Reference Manual.

W9GFO
03-24-2010, 12:19 PM
Is the Basic Stamp fast enough? I think the Propeller chip would be a much better fit for this.

Rich H

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The Simple Servo Tester, a kit from Gadget Gangster. (http://www.gadgetgangster.com/206)

Remington Baker
03-24-2010, 02:27 PM
Microchip has an apliction note for bldc control using the PIC16F877 which is 5 mips, the same as the PIC16F57 in the BS2. so I am asuming it will work to some extent but I dont know how many rpms I can get out of it. I think the ap note is more geared tward industrial aplications and I want to use it for an rc racing motor that supposedly can spin 60000 rpm. so does anyone know if it can work has anyone tryed it.

W9GFO
03-24-2010, 02:46 PM
A BS2 will perform about 4,000 instructions per second. Not fast enough for a brushless controller.

It may use the same PIC16 but what makes it a Basic Stamp is the code that is already on the chip.

Rich H

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The Simple Servo Tester, a kit from Gadget Gangster. (http://www.gadgetgangster.com/206)

Remington Baker
03-24-2010, 02:51 PM
Thanks for the advice can you suggest any micro controllers that are good for bldc control besides propeler and if I went with a prop is it very good for my aplication

W9GFO
03-24-2010, 03:05 PM
The only experience I have with brushless controllers is connecting them up to various RC flying things. I am sure that the Propeller chip would work for this but I do not know that anyone has yet done it.

Rich H

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The Simple Servo Tester, a kit from Gadget Gangster. (http://www.gadgetgangster.com/206)

Remington Baker
03-24-2010, 03:27 PM
Thank you for your advice