Brian Cooke

> I did not see a change that could be added from issue #336 so I could be missing something there. There is no PR or changes for fixing [raspberrypi/pico-sdk#336](https://github.com/raspberrypi/pico-sdk/issues/336)...

@jomoengineer There are a few different Raspberry Pi Pico Arduino Cores available at the moment. Which one did you use? The scan bus example in pico-examples doesn't scan I2C addresses...

> I have an actual Raspberry Pi Pico: > [https://www.raspberrypi.org/products/raspberry-pi-pico/](url) Yes. I meant something different. Above you mentioned you installed Arduino IDE and Pico Board support. Which Pico Board support...

If I understand the code correctly, the Raspberry Pi Pico Arduino core linked to above uses a special bit-banged 0-byte write for scanning the I2C bus. See [here](https://github.com/earlephilhower/arduino-pico/blob/1.1.0/libraries/Wire/Wire.cpp#L261-L262) and [here](https://github.com/earlephilhower/arduino-pico/blob/1.1.0/libraries/Wire/Wire.cpp#L198-L247)....

If you would like to scan the I2C bus using a 1-byte write to see if it works you could give [this](https://github.com/fivdi/rp2040-tests/tree/master/i2c/bus_scan_issue_278) a try. Note that this example assumes that...

> I am using the 'i2c.c code that was posted previously and I have the '3rd thing to try' code implemented. This was the correct thing to do. > Should...

I am now the proud owner of a Grove 16 x 2 LCD and did some tests with it. If an attempt is made to read a byte from the...

> Also, with the code changes that were suggested, a PCF8574 based LCD no longer worked with either the bus_scan or the lcd_1602_i2c example . I ended up re-cloning the...

> It is a long shot, however this might be related to [raspberrypi/pico-sdk#708](https://github.com/raspberrypi/pico-sdk/issues/708) even though in that case the hang in `i2c_read_blocking` happens for any size of data transfer, not...

I've seen similar issues with serial communication when the internal calibrated RC oscillator is used as a clock source. The the internal calibrated RC oscillator provides an approximate 8.0MHz clock...