I didn’t modify the code for arduino in any way, I think everything is set up correctly. Still, I tried to adjust the #define I2C_ADDRESS from 8 to 0x08 but it’s the same. I also tried to adjust Serial.begin (115200) to 50000 (ESPhome in the log: [i2c: 031]: Frequency: 50000 Hz) but it also doesn’t work.
main.ino - Arduino code
/*
Ports:
0 0 .. 13 13
A0: 14, A1: 15, A2: 16, A3: 17: A4: 18: A5: 19: A6: 20, A7: 21
port bits: 5 ... 0..32
0: 0: 00000
1: 1: 00001
A7: 21: 10101
*/
#include <Arduino.h>
#include <Wire.h>
//#define DEBUG // remove debug so pin 0 and 1 can be used for IO
#define I2C_ADDRESS 8
void onRequest();
void onReceive(int);
void setup()
{
#ifdef DEBUG
Serial.begin(115200);
Serial.println(F("Init "));
#endif
analogReference(INTERNAL);
Wire.begin(I2C_ADDRESS);
Wire.onRequest(onRequest);
Wire.onReceive(onReceive);
#ifdef DEBUG
Serial.println(F("Wire ok"));
#endif
}
void loop()
{
//int temp = analogRead(A1);
//Serial.println(temp);
}
volatile byte buffer[3];
volatile byte len = 1;
#define DIGITAL_READ(b, pin, mask) \
if (digitalRead(pin)) \
buffer[b] |= mask;
void readDigital()
{
len = 3;
buffer[0] = 0;
DIGITAL_READ(0, 0, 1);
DIGITAL_READ(0, 1, 2);
DIGITAL_READ(0, 2, 4);
DIGITAL_READ(0, 3, 8);
DIGITAL_READ(0, 4, 16);
DIGITAL_READ(0, 5, 32);
DIGITAL_READ(0, 6, 64);
DIGITAL_READ(0, 7, 128);
buffer[1] = 0;
DIGITAL_READ(1, 8, 1);
DIGITAL_READ(1, 9, 2);
DIGITAL_READ(1, 10, 4);
DIGITAL_READ(1, 11, 8);
DIGITAL_READ(1, 12, 16);
DIGITAL_READ(1, 13, 32);
DIGITAL_READ(1, A0, 64);
DIGITAL_READ(1, A1, 128);
buffer[2] = 0;
DIGITAL_READ(2, A2, 1);
DIGITAL_READ(2, A3, 2);
// I2C
//DIGITAL_READ(2, A4, 4);
//DIGITAL_READ(2, A5, 8);
// DIGITAL READ not supports on A3 .. A7
#ifdef DEBUG_READ
Serial.print(F("Read 3 bytes: "));
Serial.print(buffer[0]);
Serial.print(' ');
Serial.print(buffer[1]);
Serial.print(' ');
Serial.println(buffer[2]);
#endif
}
void readAnalog(int pin)
{
int val = analogRead(A0 + pin);
len = 2;
buffer[0] = val & 0xFF;
buffer[1] = (val >> 8) & 0b11;
#ifdef DEBUG_READ
Serial.print(F("Read analog pin "));
Serial.println(pin);
#endif
}
void onRequest()
{
Wire.write(const_cast<uint8_t *>(buffer), len);
}
#define CMD_DIGITAL_READ 0x0
#define CMD_WRITE_ANALOG 0x2
#define CMD_WRITE_DIGITAL_HIGH 0x3
#define CMD_WRITE_DIGITAL_LOW 0x4
#define CMD_SETUP_PIN_OUTPUT 0x5
#define CMD_SETUP_PIN_INPUT_PULLUP 0x6
#define CMD_SETUP_PIN_INPUT 0x7
// 8 analog registers.. A0 to A7
// A4 and A5 not supported due to I2C
#define CMD_ANALOG_READ_A0 0b1000 // 0x8
// ....
#define CMD_ANALOG_READ_A7 0b1111 // 0xF
#define CMD_SETUP_ANALOG_INTERNAL 0x10
#define CMD_SETUP_ANALOG_DEFAULT 0x11
void onReceive(int numBytes)
{
#ifdef DEBUG_READ
Serial.print("Received bytes: ");
Serial.println(numBytes);
#endif
int cmd = Wire.read();
switch (cmd)
{
case CMD_DIGITAL_READ:
readDigital();
break;
}
if (cmd >= CMD_ANALOG_READ_A0 && cmd <= CMD_ANALOG_READ_A7)
{
readAnalog(cmd & 0b111);
return;
}
int pin = Wire.read();
switch (cmd)
{
case CMD_WRITE_DIGITAL_HIGH:
case CMD_WRITE_DIGITAL_LOW:
{
bool output = cmd == CMD_WRITE_DIGITAL_HIGH;
digitalWrite(pin, output);
#ifdef DEBUG
Serial.print(F("Pin "));
Serial.print(pin);
Serial.println(output ? F(" HIGH") : F(" LOW"));
#endif
break;
}
case CMD_WRITE_ANALOG:
{
int val = Wire.read() & (Wire.read() << 8);
analogWrite(pin, val);
#ifdef DEBUG
Serial.print(F("Pin "));
Serial.print(pin);
Serial.print(F(" Analog write "));
Serial.println(val);
#endif
break;
}
case CMD_SETUP_PIN_OUTPUT:
pinMode(pin, OUTPUT);
#ifdef DEBUG
Serial.print(F("Pin "));
Serial.print(pin);
Serial.println(F(" OUTPUT"));
#endif
break;
case CMD_SETUP_PIN_INPUT:
pinMode(pin, INPUT);
#ifdef DEBUG
Serial.print(F("Pin "));
Serial.print(pin);
Serial.println(F("INPUT"));
#endif
break;
case CMD_SETUP_PIN_INPUT_PULLUP:
pinMode(pin, INPUT_PULLUP);
#ifdef DEBUG
Serial.print(F("Pin "));
Serial.print(pin);
Serial.println(F("INPUT PULLUP"));
#endif
break;
case CMD_SETUP_ANALOG_INTERNAL:
analogReference(INTERNAL);
#ifdef DEBUG
Serial.println(F("Analog reference INTERNAL"));
#endif
break;
case CMD_SETUP_ANALOG_DEFAULT:
analogReference(DEFAULT);
#ifdef DEBUG
Serial.println(F("Analog reference DEFAULT"));
#endif
break;
}
}
