MCP23017 подключена к GPIO5(SCL) и GPIO4(SDA). Запускаю сканер - не находит. Подключил заведомо рабочий модуль DS1307 - тоже не находит В чем причина? Спойлер: Стандартный скетч поиска Код (C++): #define I2C_SCL 5 #define I2C_SDA 4 #include <Wire.h> void setup() { Wire.begin(I2C_SDA, I2C_SCL ); Serial.begin(19200); while (!Serial); // Leonardo: wait for serial monitor Serial.println("\nI2C Scanner"); } void loop() { byte error, address; int nDevices; Serial.println("Scanning..."); nDevices = 0; for (address = 1; address < 127; address++ ) { // The i2c_scanner uses the return value of // the Write.endTransmisstion to see if // a device did acknowledge to the address. Wire.beginTransmission(address); error = Wire.endTransmission(); if (error == 0) { Serial.print("I2C device found at address 0x"); if (address < 16) Serial.print("0"); Serial.print(address, HEX); Serial.println(" !"); nDevices++; } else if (error == 4) { Serial.print("Unknown error at address 0x"); if (address < 16) Serial.print("0"); Serial.println(address, HEX); } } if (nDevices == 0) Serial.println("No I2C devices found\n"); else Serial.println("done\n"); delay(5000); }