topic Re: Communication between SJA1124 and Raspberry PI in Other NXP Products

Communication between SJA1124 and Raspberry PI

Khaled_tn — Tue, 01 Aug 2023 12:19:14 GMT

Hello, I am trying to send SPI frames to the evaluation board SJA1124EVB from my raspberry PI, I followed the Quick Start Guide of the board and I :
- Powered the board with 12V
- Made all the necessary SPI wiring(SCK, SDO, SDI, SPI chip select input #0)
- Provided a 2MHz clock for the board from an external oscillator
-Send SPI frames for the board using the software NXP_SJA1124_Example_App provided in the NXP website(SJA1124_Init, Lin_Init, SJA1124_GetStatus, ...)

when running the script my oscilloscope shows the frames in SDI, also shows a normal functionning of the L_INH0, a normal SCK but I for the SDO I am receinving a weird signal (not noise) as if it is not in the good level or not enough amplified.
You can find the signal SDO received.
Can you help to figure out what I may forgot or what could be wrong ?
Thanks

Re: Communication between SJA1124 and Raspberry PI

ErikaC — Tue, 01 Aug 2023 18:52:27 GMT

Hello,

Could you attach a picture of your oscilloscope with the clock signal and the SDI signal, as well as you could check that there is VDD voltage (3.3V / 5V), P3V3 (3.3V) and P5V0 (5V) as reference voltages, to check the operation of the board?

Re: Communication between SJA1124 and Raspberry PI

Khaled_tn — Wed, 02 Aug 2023 08:43:56 GMT

Hello Erica, thanks you for responding.
So you will find the signals SCK, SDI and the CLK ,concerning VDD I checked it's 3.3V, as for P3V3 and P5V0 they are both 0V

Re: Communication between SJA1124 and Raspberry PI

ErikaC — Wed, 02 Aug 2023 18:44:32 GMT

Hello,

You should measure P3V3 (3.3V) and P5V0 (5V). Otherwise, SJA1124 and other components on the boards can be damaged. Do you have another SJA1124EVB to check it? Because I do not see errors with the signals and the steps you are following.

Regards

Re: Communication between SJA1124 and Raspberry PI

Khaled_tn — Thu, 03 Aug 2023 15:54:57 GMT

Hello again,

I realized that I had to apply a 3.3V in the VDD (J3-2) pin to the board, even though I had already measured 3.3V in it.
That made me get response to my SPI frames that I've sent, although the frames I am receiving are identical to the ones I am sending even when calling "SJA1124_GetStatus" function that reads the Interruptions registers.

for example, after calling the SJA1124_Init, I've sent the frame {0x10, 0x83, 0, 0, 0, 0} to read the interruptions registers I've received the Identical frame from the SDO pin from the board. (Image attached)

Do you have any idea haw should normally the board responds to the SPI frames (through the SDO pin)?
Thanks.