Problem with I2C prototol (adafruit BNO055)

[jacu97]

Hi everyone, my name is Javier.

I'm implementing an I2C master on a PYNQ-Z1 board from Xilinx. I'm using it to read from an adafruit BNO055 and I'm having a lot of troubles. The discussion for this it's here:

https://forums.xilinx.com/t5/General-Technical-Discussion/I2C-problem-with-BNO055/m-p/1011547

I would be pleased to find a solution, or at least some more ideas to try. Beforehand thank you.

[o_o]

Hi Jacu,

I haven't read the whole thread, but I see many snapshots from simulation data, and not a single one of the real bus. To be able to help you, please export the data from the bus, along with what it is supposed to be.

We usually use Saleae Logic analyzers, they are excellent, but an oscilloscope output could also work.

Simply compare the actual protocol on your bus with the Bosch protocol, (page 93 of the current datasheet)

https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BNO055-DS000.pdf


PS: I do see your last post about "spikes" during the ACK. This is normal, when the SDA transitions from being host-controlled to being slave-controlled, this happens. Only the status during rising edge of the SCL matters.