dacsticle.py

# SPDX-FileCopyrightText: 2023 Liz Clark for Adafruit Industries
# SPDX-License-Identifier: MIT

"""Simple demo of writing a sine wave to the AD569x DAC."""

import math
import board
import busio
from adafruit_seesaw import seesaw, rotaryio, digitalio
import adafruit_ad569x


i2c = busio.I2C(board.SCL1, board.SDA1, frequency=400_000)

# Initialize AD569x
dac = adafruit_ad569x.Adafruit_AD569x(i2c)


# length of the sine wave
LENGTH = 1000

# sine wave values written to the DAC
sin_value = [
    int(math.sin(math.pi * 2 * i / LENGTH) * ((2**15) - 1) + 2**15)
    for i in range(LENGTH)
]

tri_value = [
    int((2 * math.acos(math.sin(math.pi * 2 * i / LENGTH))) / math.pi * ((2**15) - 1))
    for i in range(LENGTH)
]

saw_value = [
    int((i / LENGTH) * ((2**15) - 1))
    for i in range(LENGTH)
]

seesaw = seesaw.Seesaw(i2c, 0x36)
seesaw.pin_mode(24, seesaw.INPUT_PULLUP)
button = digitalio.DigitalIO(seesaw, 24)
button_held = False
encoder = rotaryio.IncrementalEncoder(seesaw)
last_position = None

print("AD5693 16-bit DAC")


while True:
    for v in saw_value:
        dac.value = v

    position = -encoder.position

    if position != last_position:
        last_position = position
        print("Position: {}".format(position))

    if not button.value and not button_held:
        button_held = True
        print("Button pressed")

    if button.value and button_held:
        button_held = False
        print("Button released")