PCA9698-micropython-driver

This repository contains a MicroPython driver for the PCA9698, a 40-bit I/O port expander with interrupt and reset features. The driver allows for easy control and configuration of the PCA9698's input and output ports via I2C communication.

Features

• Set pin and port modes (input/output)
• Read and write individual pins
• Read entire ports
• Toggle all output ports
• Interrupt handling

Usage

To use this driver, instantiate the PCA9698 class with an I2C object and the I2C address of the PCA9698 device. Then, use the provided methods to control the I/O ports.

Acknowledgment

This MicroPython driver is adapted from an Arduino version of the PCA9698 driver provided by Justin-Pl.

PCA9698.cpp

PCA9698.h

Test

from machine import SoftI2C, Pin
import PCA9698
import time

#DRV8833_MOTOR_DRIVER_STBY = Pin(17, Pin.OUT)
#DRV8833_MOTOR_DRIVER_STBY.value(1)
PCA9698_OE_ = Pin(48, Pin.OUT)  # active LOW
PCA9698_OE_.value(0)  # Set the OE pin to low to enable the output
i2c = SoftI2C(scl=Pin(3), sda=Pin(2), freq=400000)  # Initialize I2C with SCL on Pin 3, SDA on Pin 2, and frequency of 400kHz
devices = i2c.scan()  # Scan for devices on the I2C bus
print("found devices:", [hex(device) for device in devices])  # Print the addresses of found devices in hexadecimal format
pca_1 = PCA9698.PCA9698(iic=i2c, address=0x20)  # Create an instance of PCA9698 with I2C address 0x20
#pca_2 = PCA9698.PCA9698(iic=i2c, address=0x21)
#pca_3 = PCA9698.PCA9698(iic=i2c, address=0x22)
pcas = [pca_1]#[pca_1, pca_2, pca_3]
for pca_num, pca in enumerate(pcas):
    print(f"Set all ports to mode 'input'")
    pca.set_ports_mode([0,0,0,0,0])  # Set all ports of PCA9698 to output mode
    pca.update_all()
    for port_num in range(5):
        mode_dict = {0x00: "output", 0xFF: "input"}
        print(f"pca_{pca_num}:port {port_num} mode: {mode_dict.get(pca.read_port_mode(port_num), 'unknown')}")
    print(f"Set all ports to mode 'output'")
    pca.set_ports_mode([1,1,1,1,1])  # Set all ports of PCA9698 to output mode
    pca.update_all()
    for port_num in range(5):
        mode_dict = {0x00: "output", 0xFF: "input"}
        print(f"pca_{pca_num}:port {port_num} mode: {mode_dict.get(pca.read_port_mode(port_num), 'unknown')}")
#pca_1.set_port_mode(port_num=0, mode=1)
#pca_1.set_port_mode(port_num=1, mode=1)
#pca_1.set_port_mode(port_num=2, mode=1)
#pca_1.set_port_mode(port_num=3, mode=1)
#pca_1.set_port_mode(port_num=4, mode=1)
time.sleep(0.5)  # Delay for 0.5 seconds

for pca_num, pca in enumerate(pcas):
    print(f"pca_{pca_num}:drive on")  # Indicate that driving the pins is starting
    for pin_num in range(40):
        pca.write_pin(pin_num, 1)  # Set each pin to high
        print(f"pca_{pca_num}: pin:{pin_num}", "read again:", pca.read_pin(pin_num))  # Print the pin number and read back its status
        #new_status = pca.write_pin(pin_num, 1)  # on
        #print(f"pca_{pca_num}: pin:{pin_num}", "new_status:", new_status, "read again:", pca.read_pin(pin_num))

    time.sleep(1)  # Delay for 1 second
    print(f"pca_{pca_num}:drive off")  # Indicate that driving the pins is stopping
    for pin_num in range(40):
        pca.write_pin(pin_num, 0)  # Set each pin to low
        print(f"pca_{pca_num}: pin:{pin_num}", "read again:", pca.read_pin(pin_num))  # Print the pin number and read back its status
        #new_status = pca.write_pin(pin_num, 0)  # off
        #print(f"pca_{pca_num}: pin:{pin_num}", "new_status:", new_status, "read again:", pca.read_pin(pin_num))
    
    time.sleep(1)
    pca.toggle_all_ports()
    print(f"pca_{pca_num}:toggle", [pca.read_pin(pin_num) for pin_num in range(40)])
    time.sleep(1)
    pca.toggle_all_ports()
    print(f"pca_{pca_num}:toggle", [pca.read_pin(pin_num) for pin_num in range(40)])

    # Testing interrupt functionality
    print(f"pca_{pca_num}:Setting up interrupts for PCA9698")
    # Enable interrupts for the first 5 pins of the first PCA device
    interrupt_enabled = True
    for pin_num in range(5):
        pca.set_interrupt(pin=pin_num, enable=1)
        #print(f"pca9698_{pca_num}:Interrupt enabled on pin {pin_num}")

    # Check and print the interrupt mask status
    for pin_num in range(5):
        mask_status = pca.read_interrupt_mask(pin_num // 8)
        #print(f"pca9698_{pca_num}:Interrupt mask status for port {pin_num // 8}: {bin(mask_status)}")

    # Simulate pin state change and check for interrupt response
    print(f"pca_{pca_num}:Simulating pin state changes and checking interrupt responses")
    for pin_num in range(5):
        pca.write_pin(pin_num, 1)  # Set pin high
        time.sleep(0.1)  # Short delay to simulate real conditions
        pca.write_pin(pin_num, 0)  # Set pin low
        # Read pin state to confirm if interrupt was triggered
        pin_state = pca.read_pin(pin_num)
        if pin_state == 0:
            #print(f"pca9698_{pca_num}:Pin {pin_num} state correct after toggle, interrupt functionality OK")
            pass
        else:
            print(f"pca_{pca_num}:Pin {pin_num} state incorrect after toggle, interrupt functionality may have issues")
            interrupt_enabled = False

    if interrupt_enabled:
        print(f"pca_{pca_num}:Interrupt functionality normal for all tested pins")
        pass
    else:
        print(f"pca_{pca_num}:Some pins may have issues with interrupt functionality, please check hardware or configuration")

    # Disable all interrupts
    print(f"pca_{pca_num}: Disabling interrupts")
    for pin_num in range(40):
        pca.set_interrupt(pin=pin_num, enable=0)
    print(f"pca_{pca_num}:Interrupts disabled for all pins")
    print("#############")