2 problems of Nucleo-G031K8 using SPI to communicate between Master and Slave

[JFung.1]

Background:

- Using SPI to communicate between 2 MCU (Master and Slave)

- Connection:

      G031K8 (Master) <=> G031K8 (Slave)

               MOSI <=>MISO

               MISO <=> MOSI

               SCK<=> SCK

               NSS <=>NSS

Problem 1: Slave MCU could not receive the data

Master:

- output the Data array by SPI in DMA mode

- output data are correct and checked by Logic analyser

Slave:

- No matter how the SPI setting is, received data are always 0xFF

- SPI DMA have fired event but the data are always 0xFF

- Tried to set both side have CRC, the slave side have CRC error occur but the DMA content are 0xFF

- Tried to use polling method, but same result.

Could anyone advise me what should I check on next step?

Problem 2 – MOSI/MISO pin voltage cut half when using slave side using “Full-Duplex Slave”

- When Slave MCU selected the “Full-Duplex Slave”, The MOSI pin voltage cut half.

- When Slave MCU selected the “Receive Only Slave”, The MOSI pin voltage became normal

(but still have problem of received data by DMA at problem 1)

(Yellow is MOSI/MISO, Blue is NSS)

Full-Duplex Slave:

Receive Only Slave:

Why the Voltage become cut half?

I have tried the GPIO setting but nothing change.

[Mike_ST · Accepted solution]

Hello,

>> - Connection:

>> G031K8 (Master) <=> G031K8 (Slave)

>> MOSI <=>MISO

>> MISO <=> MOSI

You have to connect MOSI of the master to the MOSI of the slave, and  MISO of the master to the MISO of the slave.

[EZHON.1]

connection issue, it's different with the UART communication.

[JFung.1]

Thank you very much.

It is working now.