# simple motor driver
# L293D

# connections
# GP14 --> 1A
# GP15 --> 2A
# GP16 --> 1,2EN

import machine
import utime

ch_1A = machine.Pin(14, mode = machine.Pin.OUT)
ch_2A = machine.Pin(15, mode = machine.Pin.OUT)

# set PWM freqency to 1kHz.
# duty to 0
pwm = machine.PWM(machine.Pin(16))
pwm.freq(1000)
pwm.duty_u16(0)

def motor_driver(duty, direction):
    global ch_1A, ch_2A, pwm
    
    duty = int(duty * 65535/100)
    
    pwm.duty_u16(duty)
    if duty != 0:
        if direction == 0:
            ch_1A.value(1)
            ch_2A.value(0)
        else:
            ch_1A.value(0)
            ch_2A.value(1)
    else:
        ch_1A.value(0)
        ch_2A.value(0)
         
# main program
# turn motor in CW direction
while True:
    motor_driver(100, 0)
    utime.sleep(2)
    motor_driver(50, 1)
    utime.sleep(2)