tb6612 — TB6612 motor driver

The tb6612 module provides a driver for the TB6612 motor driver. It exposes a Motor class for driving a single DC motor on one of two channels and a Stepper class for driving a 4-wire stepper motor.

Both classes use pyb.Timer(4) at 1 kHz on pins P7 and P8 for PWM power output. The Motor direction pins are P3/P2 (channel 1) and P1/P0 (channel 2). The Stepper uses all four pins (P3, P2, P1, P0) plus both PWM channels.

Example:

from tb6612 import Motor, Stepper

m = Motor(1)
m.set_speed(50)      # 50% duty forward

s = Stepper(stepnumber=200, rpms=2, power=50)
s.step(100)          # advance 100 steps

class Motor

class tb6612.Motor(channel: int)

Construct a DC motor controller bound to one of the two TB6612 channels.

  • channel: Motor channel number. 1 uses direction pins P3/P2 and PWM pin P7 (timer 4, channel 1). 2 uses direction pins P1/P0 and PWM pin P8 (timer 4, channel 2).

set_speed(pwm: int) → None

Set the motor speed and direction.

  • pwm: Signed duty cycle in the range -100 to 100. Positive values drive the motor forward, negative values drive it in reverse. The absolute value is applied as the PWM duty cycle percentage to the power pin.

class Stepper

class tb6612.Stepper(stepnumber: int = 200, rpms: int = 2, power: int = 50)

Construct a 4-wire stepper motor controller. Initializes direction pins P3, P2, P1, P0 and the two PWM power channels on P7 and P8, then applies the requested speed and power.

  • stepnumber: Number of full steps per revolution of the connected stepper motor. Used together with rpms to compute the inter-step delay.

  • rpms: Target rotation speed in revolutions per minute. Forwarded to set_speed().

  • power: PWM duty cycle percentage (0-100) applied to both power channels. Forwarded to set_power().

phase_list() → Generator[tuple[int, int, int, int], None, None]

Generator that endlessly yields the four-phase drive pattern (1, 0, 0, 0), (0, 0, 1, 0), (0, 1, 0, 0), (0, 0, 0, 1) used by step(). Each tuple element is the value to write to pin1, pin2, pin3, pin4 respectively.

set_speed(rpms: int) → None

Update the stepping speed.

  • rpms: Target rotation speed in revolutions per minute. The per-half-step delay (in microseconds) is recomputed as 1000000 / (rpms * stepnumber) / 2.

set_power(power: int) → None

Set the PWM duty cycle applied to both power channels.

  • power: Duty cycle percentage in the range 0 to 100.

step(num: int) → None

Advance the stepper by num phase transitions, applying the next phase from phase_list() and waiting the configured inter-step delay (via pyb.udelay) between transitions.

  • num: Number of phase steps to advance. Each call to step advances exactly this many phases; direction is fixed (the underlying phase generator only iterates forward).