3-bldc

3-bldc

3-phase brushless DC motor controller

Features:

• controls 3-phase BLDC motor
• synchronization using opto-sensors

Arduino peripherals usage:

• Timer0 - PWM
• Timer1 - generic timer, phase detection
• PB0:5 - phase output
  • PB0: phase 1 - high
  • PB1: phase 2 - high
  • PB2: phase 3 - high
  • PB3: phase 1 - low
  • PB4: phase 2 - low
  • PB5: phase 3 - low
• PC0/PCINT8 - ~FAULT - overcurrent detection
• PC3/ADC3 - output current measurement
• PD0:1 - serial communication
• PD2/INT0 = (zero angle = home position) detection (triggered by both edges)
• PD3/INT1 = step sensor A
• PD4 = step sensor B
• PD5 = OC0B = PWM output

Issues:

• opto-sensor feedback is currently amplified by operating amplifiers. Unfortunately, these devices should operate on higher voltage, so amplification is not so stable and produces flicking. Solution: signal from opto-sensors should be amplified and conditioned by CMOS invertor based schmitt trigger.

TODO:

• rotation feedback could be derived from back-EMF.
• maximum speed, acceleration measurements
• use avrm modules for usart communication and text formating (comf)