i2c_port_address_scanner.c

//
// Created by francis on 6/11/20.
//

/*
* i2c_port_address_scanner
* Scans ports D0 to D7 on an ESP8266 and searches for I2C device. based on the original code
* available on Arduino.cc and later improved by user Krodal and Nick Gammon (www.gammon.com.au/forum/?id=10896)
* D8 throws exceptions thus it has been left out
*
*/

#include <Wire.h>

void setup()
{
	Serial.begin(115200);
	while (!Serial);             // Leonardo: wait for serial monitor
	Serial.println(
		"\n\nI2C Scanner to scan for devices on each port pair D0 to D7");
	scanPorts();
}

uint8_t portArray[] = {16, 5, 4, 0, 2, 14, 12, 13};

//String portMap[] = {"D0", "D1", "D2", "D3", "D4", "D5", "D6", "D7"}; //for Wemos
String portMap[] =
	{"GPIO16", "GPIO5", "GPIO4", "GPIO0", "GPIO2", "GPIO14", "GPIO12",
	 "GPIO13"};

void scanPorts()
{
	for (uint8_t i = 0; i < sizeof(portArray); i++) {
		for (uint8_t j = 0; j < sizeof(portArray); j++) {
			if (i != j) {
				Serial.print(
					"Scanning (SDA : SCL) - " + portMap[i] + " : " + portMap[j]
						+ " - ");
				Wire.begin(portArray[i], portArray[j]);
				check_if_exist_I2C();
			}
		}
	}
}

void check_if_exist_I2C()
{
	byte error, address;
	int nDevices;
	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("Unknow error at address 0x");
			if (address < 16)
				Serial.print("0");
			Serial.println(address, HEX);
		}
	} //for loop
	if (nDevices == 0)
		Serial.println("No I2C devices found");
	else
		Serial.println("**********************************\n");
	//delay(1000);           // wait 1 seconds for next scan, did not find it necessary
}

void loop()
{
}