SPI master and slave loop back test, but the slave is receive 0x00 bytes at all

[huaminhtuan]

Hi everyone,

I am using NRF52832 and I use SPI as communication protocol. I check my SPI master by connect its MOSI and MISO pins together, and it works correctly. Now I want to check my SPI slave. I connect SPI slave and SPI master as below:

SPI master------SPI slave
MOSI-------------MOSI
MISO-------------MISO
SCK--------------SCK
CSN--------------CSN

When I send the string "Nordic is the best" from SPI master to SPI slave, all slave bytes received i s 20 0x00 bytes. Can you help me please? Thanks for reading!

[Jørgen Holmefjord]

Are you sure you connected the correct pins? Do you use the spi and spis examples in the SDK? Which SDK version are you using? Are you trying this with two nRF52 DKs?

[huaminhtuan]

I have checked pins, they are correct and I am using SDK 13.0.0. I have only 1 PCA10040, nRF52832 board, and I create 1 SPI master 0 and 1 SPI slave 1.

[Jørgen Holmefjord]

What is the slave device? Which pins are you using on the PCA10040? Have you checked the SPI lines with a logic analyzer to see if it is actually sending anything?

[huaminhtuan]

hi Jørgen Holmefjord,

I set up SPIM0 as master and SPIS1 as slave and I use pins below

SPI master------SPI slave
p13 MOSI-------------MOSI p17
p14 MISO-------------MISO p18
p12 SCK--------------SCK p16
p11 CSN--------------CSN p15

I also check SPI lines with a oscilloscope and it work correctly.

[Jørgen Holmefjord]

Have you modified the PCA10040 board? Note that P0.13-P0.18 is used for buttons and LEDs, and might not work with other peripherals without modification to the board and application. Could you upload your code for debugging?