Hi everyone,
Again with STM32F, i have to interface an STM32F101 with an STM32L05 via SPI, the STM32L is configured as master , the STM32F1 as slave, using 8 bytes buffering with RX and TX DMA. The test code is simple, master send those 8 bytes and the slave must respond by sending back those 8 bytes...For master things are good i can receive and send data no problem at all. For the slave well, it receive right data , but it only send them back right at the third read mean :
--First transmission
MOSI : 0xAA 0x01 0x07 0x01 0x01 0x01 0x01 0x01
MISO: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
Normal, and as expected
--2nd transmission
MOSI : 0xAA 0x01 0x07 0x01 0x01 0x01 0x01 0x01
MISO: 0x00 0x01 0x07 0x01 0x01 0x01 0x01 0x01
0xAA is missing on the MISO
--3rd transmission
MOSI : 0xAA 0x01 0x07 0x01 0x01 0x01 0x01 0x01
MISO: 0xAA 0x01 0x07 0x01 0x01 0x01 0x01 0x01
Correct data out of the slave !!
i can't see what's seems to be the problem
anyone had a similar problem before, please advice.