www.mischianti.org

MicroPython Library to use i2c analog IC with arduino and esp8266. Can read analog value and write analog value with only 2 wire (perfect for ESP-01).

Changelog

• 07/11/2023: v0.0.3 Fix on read when write is active and running #Forum
• 16/05/2023: v0.0.2 Minor fix on read and write #Forum
• 18/04/2023: v0.0.1 Initial commit of stable version.

I try to simplify the use of this IC, with a minimal set of operation.

Installation

To install the library execute the following command:

pip install pcf8591-library

Constructor: Pass the address of I2C

from PCF8591 import PCF8591
from machine import I2C, Pin
    
# Initialize the I2C bus
i2c = I2C(0, scl=Pin(22), sda=Pin(21))  

# Initialize the PCF8591
pcf8591 = PCF8591(0x48, i2c)
if pcf8591.begin():
    print("PCF8591 found")

or

from PCF8591 import PCF8591

pcf8591 = PCF8591(0x48, sda=21, scl=22)
if pcf8591.begin():
    print("PCF8591 found")

To read all analog input in one

# Main loop
while True:
    # Read all analog input channels
    ain0, ain1, ain2, ain3 = pcf8591.analog_read_all()

    # Print the results
    print("AIN0:", ain0, "AIN1:", ain1, "AIN2:", ain2, "AIN3:", ain3)

    # Wait for 1 second
    utime.sleep(1)

If you want to read a single input:

print("AIN0 ", pcf8591.analog_read(PCF8591.AIN0))
print("AIN1 ", pcf8591.analog_read(PCF8591.AIN1))
print("AIN2 ", pcf8591.analog_read(PCF8591.AIN2))
print("AIN3 ", pcf8591.analog_read(PCF8591.AIN3))

If you want to write a value:

pcf8591.analog_write(255)
utime.sleep(1)
pcf8591.analog_write(128)
utime.sleep(1)
pcf8591.analog_write(0)

You can also read and write voltage

pcf8591.voltage_write(3.3)
utime.sleep(1)
pcf8591.voltage_write(1.65)
utime.sleep(1)
pcf8591.voltage_write(0)

or

print("AIN0 ", pcf8591.voltage_read(PCF8591.AIN0))
print("AIN1 ", pcf8591.voltage_read(PCF8591.AIN1))
print("AIN2 ", pcf8591.voltage_read(PCF8591.AIN2))
print("AIN3 ", pcf8591.voltage_read(PCF8591.AIN3))

For the examples I use this wire schema on breadboard: