09-13-2024, 11:44 PM
Code:
/*
Made by KinCony IoT: https://www.kincony.com
Program functionality:
This program uses an ESP32-S3 to read inputs from two XL9535 I/O expander chips
(with I2C addresses 0x24 and 0x25) and one PCF8574 I/O expander (with I2C address 0x23) via I2C.
The XL9535 chips handle 1-32 channels, while the PCF8574 chip handles channels 33-40.
The program reads the state of all these inputs and prints them in binary format to the serial monitor.
Key points:
- The I2C bus is initialized on GPIO pins 11 (SDA) and 10 (SCL) with a frequency of 40kHz.
- The XL9535 chips read the state of input pins for channels 1-32.
- The PCF8574 chip reads the state of input pins for channels 33-40.
- The state of the inputs is printed to the serial monitor in binary format every second.
*/
#include <PCA95x5.h>
#include <Wire.h>
// Initialize the PCA9555 objects for XL9535 chips (1-32 channels)
PCA9555 ioex1; // For channels 1-16 (I2C address 0x24)
PCA9555 ioex2; // For channels 17-32 (I2C address 0x25)
// Define the I2C address for the PCF8574 chip (for channels 33-40)
const int pcf8574_address = 0x23;
void setup() {
// Start serial communication for debugging
Serial.begin(115200);
delay(2000); // Wait for 2 seconds to ensure everything is ready
// Initialize the I2C bus with GPIO 11 as SDA and GPIO 10 as SCL, 40kHz frequency
Wire.begin(11, 10, 40000);
// Attach the first PCA9555 device (for channels 1-16)
ioex1.attach(Wire, 0x24);
ioex1.polarity(PCA95x5::Polarity::ORIGINAL_ALL);
ioex1.direction(PCA95x5::Direction::IN_ALL); // Set all pins as inputs
// Attach the second PCA9555 device (for channels 17-32)
ioex2.attach(Wire, 0x25);
ioex2.polarity(PCA95x5::Polarity::ORIGINAL_ALL);
ioex2.direction(PCA95x5::Direction::IN_ALL); // Set all pins as inputs
}
void loop() {
// Read and print the state of inputs from the first PCA9555 (channels 1-16)
Serial.print("1-16 input states: ");
Serial.println(ioex1.read(), BIN);
// Read and print the state of inputs from the second PCA9555 (channels 17-32)
Serial.print("17-32 input states: ");
Serial.println(ioex2.read(), BIN);
// Read and print the state of inputs from the PCF8574 (channels 33-40)
Serial.print("33-40 input states: ");
byte pcf8574_state = readPCF8574();
Serial.println(pcf8574_state, BIN);
delay(1000); // Wait for 1 second before reading again
}
// Function to read the state of the PCF8574 (channels 33-40)
byte readPCF8574() {
Wire.requestFrom(pcf8574_address, 1); // Request 1 byte from PCF8574
if (Wire.available()) {
return Wire.read(); // Return the byte representing the state of inputs
} else {
return 0xFF; // Return 0xFF if no data is available (all inputs are high)
}
}
2-digital-input.zip (Size: 1.19 KB / Downloads: 46)
BIN file (you can use esp32 download tool download to ESP32-S3 with address 0x0 then directly to use) download:
2-digital-input.ino.merged.zip (Size: 187.5 KB / Downloads: 41)