I2C hardware or Software not working on STM32F103C8T6 with "generic STM32F103 series" selected

[nikisalli]

using a normal I2C scanner code, i keep getting random addresses detected. i tried with another core (roger's core) with the same hardware and code and it works but when i switch to the stm32duino core it doesn't work anymore.

code:
`#include <Wire.h>

void setup() {
Serial1.begin(115200);
Wire.begin();
Serial1.println("\nI2C Scanner");
}

void loop() {
byte error, address;
int nDevices;

Serial1.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) {
  Serial1.print("I2C device found at address 0x");
  if (address < 16) 
    Serial1.print("0");
  Serial1.println(address, HEX);

  nDevices++;
}
else if (error == 4) {
  Serial1.print("Unknown error at address 0x");
  if (address < 16) 
    Serial1.print("0");
  Serial1.println(address, HEX);
}    

}
if (nDevices == 0)
Serial1.println("No I2C devices found");
else
Serial1.println("done");

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

[fpistm]

Linked #217

[nikisalli]

Isn't there a temporary fix i can use? Because from what i see it's like six months it is broken

[LMESTM]

@nikisalli Hi - please find a proposed patch to fix the scan issue - let me know if you can test on your side.

[nikisalli]

@LMESTM i just tested your patch on the bluepill (stm32f103c8t6) and it works flawlessly

[LMESTM]

@nikisalli thanks for the quick feedback and testing !

[fpistm]

Fixed with #301