Configuring I2C on SAMD21 using the SARA AFF 412

Hi all,

I’m using the SARA AFF 412 to develop the code for a custom PCB.
On that PCB I’m using a SAMD21 as well in combination with the Ublox M8Q GPS module.

For this project, I’m not able to use the Arduino libraries or setup for communication across I2C and SPI. Furthermore the entire code will be written in normal C.
I’ve tried multiple configurations to connect the GPS module to the MCU but so far I haven’t had any success yet.

I used the datasheet from microchip as well as Ublox for all the registers and addresses, but so far I haven’t been able to get a solid connection going.
I’m monitoring the outputs on a logic analyzer.

Does anybody have any experience using these methods and if so an example I can take a look at?


Hi Dave,

If you’re not going to use the arduino framework I recommend you use ASF instead, there are a lot of examples available with ASF and scanners. If you get this working porting the library should be fairly straightforward.


Hi Thom,

I wont be using the Arduino framework indeed.
ASF would be my latest choice if I could since it will reduce the amount of flexibility.

I will use it if I cannot get it to work otherwise but I thought maybe someone came across a similar issue or has done a similar project that could guide me to right solution.