Hx8357b stm32 driver driver#

It seems that you should operate this device exclusively in 8 bit mode and simply send two bytes. That is it is not valid to change the frame from 16 to 8 bit in the middle of a transaction. This selection has to be made before enabling Sent or received is either 8-bit or 16-bit. You do not specify the specific STM32 part, so it is not possible to provide a specific user manual reference, there are at least two SPI peripheral variants across the range of STM32 parts, so it is not possible to be definitive for your part, but documentation for the STM32F1xx and STM32F2xx SPI_DR states (my emphasis):Дepending on the data frame format selection bit (DFF in SPI_CR1 register), the data If( rx_count > 0 & LL_SPI_IsActiveFlag_RXNE( spi ) ) If( tx_count > 0 & LL_SPI_IsActiveFlag_TXE( spi ) ) LL_SPI_SetRxFIFOThreshold( spi, LL_SPI_RX_FIFO_QUARTER_FULL ) LL_SPI_SetRxFIFOThreshold( spi, LL_SPI_RX_FIFO_HALF_FULL ) void spi_transmit_receive( SPI_TypeDef* spi, uint8_t* tx, uint8_t* rx, uint16_t size ) I was hoping for some ideas on what issues there could be. I'm having issues trying to run the code in debug mode due to the SPI peripheral (maybe I'm missing something) and can't output values using printf (don't have access to a UART interface).

Hx8357b stm32 driver driver#

The driver I wrote does not reflect this and is always reading a 0 from the SPI DR register. Clearly, the last 8 bits on the MISO line is 0b01110011 which is the expected data. In the image, I am probing the SCLK and MISO lines. Using an oscilloscope I was able to verify the 2 bytes were correctly transmitted and the SPI slave device responds with a byte.

I'm testing the SPI driver by writing 2 bytes to the MOSI line and listen for 1 byte on the MISO line. I'm trying to write an SPI driver using the stm32 LL libraries (for the STML4 system).