"""P9-3 Generate a sawtooth waveform using MCP4725 on I2C Bus"""
from machine import Pin, I2C

i2c = I2C(1, scl = Pin(27), sda = Pin(26), freq = 400_000)

DEV_ADDR = 0x60
i = 0

while True:
    # Create a bytearray of DAC command, high byte (D11-D4), low byte (D3-D0)
    ba = bytearray([0x40, (i >> 4) & 0xFF, (i << 4) & 0xF0])
    # Write the bytearray to MCP4725 DAC through I2C
    i2c.writeto(DEV_ADDR, ba)
    i += 1    # Increment i