I2C Wire Scanner program says "No I2C devices found" on Raspberry Pi Pico

Projects General Guidance
1 
I have a program originally written for the Arduino Nano where everything works, but Memory is too small and have to Comment out one section or another to test it piecemeal; with both sections uncommented the Memory overflows (which is why I upgraded to the Pico.)  I want to get that program working on the Pico.  I'm first trying a simple I2C Wire Scanner program, but it says "No I2C devices found".  Also tried same program on a SparkFun Thing Plus RP2040 with same results (using QWIIC connectors this time.)

Connections:

Pico	   DS3231 Real Time Clock
Gnd--------Gnd
3.3V-------3.3V
I2C0 SDA---SDA
I2C0 SCL---SCL

#include <Wire.h>
void setup() {
  Wire.begin();
  Serial.begin(9600);
  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("Unknow 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);           // wait 5 seconds for next scan
}
2

Your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advice on) your project :wink: See About the Installation & Troubleshooting category.

Please don't use code tags for the normal text in your post. We now have to scroll all the way to the right to be able to read the full message.

3

Show that code as it might be fixable.