/**
i2c port scanner based on:
  in wire library examples i2c_scanner
  https://learn.adafruit.com/adafruit-pca9548-8-channel-stemma-qt-qwiic-i2c-multiplexer/arduino


 *
 */

#include <Wire.h>

#define PCAADDR 0x70    //i2c address of the i2c multiplexer


void setup() {
  Serial.begin(115200);
  while (!Serial); // Leonardo: wait for Serial Monitor
  Serial.println("\nI2C Scanner");

}

void pcaselect(uint8_t i) {
  if (i > 7) return;
 
  Wire.beginTransmission(PCAADDR);
  Wire.write(1 << i);
  Wire.endTransmission();  
}




void scandirectports(){
  Wire.begin();
  int nDevices = 0;
  Serial.println("Scanning for i2c ports on board...");

  for (byte address = 1; address < 127; ++address) {
    // The i2c_scanner uses the return value of
    // the Wire.endTransmission to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    byte 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");
  }
  Serial.println("done scanning for i2c ports on board");
}
void scani2cmultiplexer(){
  Serial.println("Scanning for i2c ports on i2c multiplexer...");
  for (uint8_t t=0; t<8; t++) {
    pcaselect(t);
    Serial.print("PCA Port #"); Serial.println(t);

    for (uint8_t addr = 0; addr<=127; addr++) {
      if (addr == PCAADDR) continue;
      Wire.beginTransmission(addr);
      if (!Wire.endTransmission()) {
        Serial.print("Found I2C 0x");  Serial.println(addr,HEX);
      }
    }
  }
  Serial.println("done scanning for i2c ports on i2c multiplexer");
}



void loop() {
 scandirectports();
 delay(1000);
 scani2cmultiplexer();
 delay(1000);
}