Not working with Portenta H7 - M8Q - i2c

[Jens1985]

Subject of the issue

Try to get Example3 working.
Connect to the Ublox module using Wire port fails.
With i2c Scanner from Arduino Playground i2c Scanner i found the Address of the ublox.

Portenta H7 is on newest Bootloader.
Same Code work fine on MKR NB 1500.

Here the Serial read from Example-Change i2c Address
SparkFun Ublox Example Press a key to change address to 0x3F Address change failed. Beginning an I2C scan. Scanning... I2C device found at address 0x42 ! done

Any Ideas?

[PaulZC]

Hi @Jens1985 ,

This sounds horribly similar to this issue. I'm beginning to suspect there is a common 'weakness' in the Arduino core I2C code.

Please try:

• Running the bus at 100kHz.
• Removing all pull-up resistors from the bus. the u-blox module has its own internal resistors. You can safely cut the I2C pull-up split-pad links on any SparkFun u-blox breakouts you are using.

I don't have a Portenta H7 and so cannot replicate the issue here...

I'm closing this as this is almost certainly a hardware issue - and not an issue with this library.

Best wishes,
Paul