Issue with L89-H R2.0 on iMX8MP via I2C – "0x54 read not alive--19" Error

IoT Modules GNSS Module
1

Hello Team,

We are currently working with the L89-H R2.0 GNSS module and have successfully tested it on a Raspberry Pi 5 using the I2C interface along with the sample code provided by Quectel. We are able to receive NMEA messages without any issue on the RPi5 setup.

However, when we connect the same L89-H R2.0 module to an i.MX8MP-based board via the I2C bus and run the same sample binary, we encounter the following error:

0x54 read not alive–19

We have verified the I2C bus on the i.MX8MP board is functional and connected correctly. The device appears at the correct I2C address (0x50), but the communication fails with the above error.

Could you please help us understand what this error means and what could be causing it on the i.MX8MP board, even though the same setup works on the Raspberry Pi 5?

Any guidance or debug tips would be appreciated.

Thanks & regards,
prem.

2

Hi team,
Any inputs on this query.

3

Hi prem0919,

I’ve done some research, and the 0x54 read not alive (-19) error likely indicates an I2C bus communication failure or timeout. The -19 error code corresponds to the Linux system error “No such device.” This suggests an I2C connectivity problem.

Could you:
Confirm there was no concurrent access blocking the module?
Check signal integrity with an oscilloscope?

BR,
June