EnviroDIY

2020-10-29 at 2:19 PM #14750

Moderator

Also try flipping the SCL and SDA pins if you’re getting nothing. Some versions of the Mayfly had them labeled backwards.

Also on a Mayfly you should always be finding a device at 0x48 and at 0x68. Those are the clock and the extra ADC. If the Walrus is responding, it should show up as a third device.

Scanner code for the Mayfly:

// This sketch tests the standard 7-bit addresses
// Devices with higher bit address might not be seen properly.
//

#include <Arduino.h>
#include <Wire.h>

void scan() {
    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("    Unknown error at address 0x");
            if (address < 16) Serial.print("0");
            Serial.println(address, HEX);
        }
    }
    if (nDevices == 0) Serial.println("No I2C devices found");
}


void setup() {
    pinMode(22, OUTPUT);

    Serial.begin(9600);
    Serial.println("\nI2C Scanner");
    digitalWrite(22, HIGH);
    Wire.begin();
}


void loop() {
    Serial.println("Hardware I2C Objects:");
    scan();

    delay(5000);  // wait 5 seconds for next scan
}

// This sketch tests the standard 7-bit addresses

// Devices with higher bit address might not be seen properly.

#include <Arduino.h>

#include <Wire.h>

void scan() {

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(" Unknown error at address 0x");

if (address < 16) Serial.print("0");

Serial.println(address, HEX);

}

if (nDevices == 0) Serial.println("No I2C devices found");

}

void setup() {

pinMode(22, OUTPUT);

Serial.begin(9600);

Serial.println("\nI2C Scanner");

digitalWrite(22, HIGH);

Wire.begin();

}

void loop() {

Serial.println("Hardware I2C Objects:");

scan();

delay(5000); // wait 5 seconds for next scan

}