Hi,
I am trying to set up a SPI communication to the STM32WL's integrated LoRa transceiver. So, I was able get NSS, MOSI and SCK to work, however I won't receive any data on the MISO line.
My code is following:
void SUBGHZSPI_DebugEnable(void) {
RCC->AHB2ENR |= (1U << 0); //enable GPIO-A
GPIOA->MODER &= ~(3U << 8); //reset PA4
GPIOA->MODER |= (2U << 8); //set PA4
GPIOA->MODER &= ~(3U << 10); //reset PA5
GPIOA->MODER |= (2U << 10); //set PA5
GPIOA->MODER &= ~(3U << 12); //reset PA6
GPIOA->MODER |= (2U << 12); //set PA6
GPIOA->MODER &= ~(3U << 14); //reset PA7
GPIOA->MODER |= (2U << 14); //set PA7
GPIOA->AFR[0] &= ~(15U<<16); //reset AF of PA4
GPIOA->AFR[0] |= (13U<<16); //set AF13 of PA4
GPIOA->AFR[0] &= ~(15U<<20); //reset AF of PA5
GPIOA->AFR[0] |= (13U<<20); //set AF13 of PA5
GPIOA->AFR[0] &= ~(15U<<24); //reset AF of PA6
GPIOA->AFR[0] |= (13U<<24); //set AF13 of PA6
GPIOA->AFR[0] &= ~(15U<<28); //reset AF of PA7
GPIOA->AFR[0] |= (13U<<28); //set AF13 of PA7
GPIOA->OSPEEDR |= (3U << 8); //set output speed for PA4 to HIGH speed
GPIOA->OSPEEDR |= (3U << 10); //set output speed for PA5 to HIGH speed
GPIOA->OSPEEDR |= (3U << 12); //set output speed for PA6 to HIGH speed
GPIOA->OSPEEDR |= (3U << 14); //set output speed for PA7 to HIGH speed
}
void SUBGHZSPI_init(void) {
RCC->APB3ENR |= (1<<0); // enable SUBGHZ SPI
SUBGHZSPI->CR1 |= (1 << 9); // SSM
SUBGHZSPI->CR1 |= (1 << 8); // SSI
SUBGHZSPI->CR1 &= ~(7 << 3);
SUBGHZSPI->CR1 |= (1<<3); // baudrate (1MHz)
SUBGHZSPI->CR1 |= (1<<2); // Master
SUBGHZSPI->CR1 &= ~(1<<10); // full-duplex
SUBGHZSPI->CR2 |= (1<<12); // FIFO threshold 8bit
SUBGHZSPI->CR1 |= (1<<6); // enable SPI
}
I call this code in main.c by executing this:
while(1) {
PWR->SUBGHZSPICR &= ~(1 << 15); // NSS low
while (!(SUBGHZSPI->SR & (1 << 1))); // TXE
*(__IO uint8_t*)(&SUBGHZSPI->DR) = 0x13;
while (!(SUBGHZSPI->SR & (1 << 0))); // RXNE
uint32_t status = SUBGHZSPI->DR;
PWR->SUBGHZSPICR |= (1 << 15); // NSS high
}
I can transmit data and can also verify with my logic level analyzer but the MISO line always stays high:
Can anyone help me getting this running? Am I missing anythin?
Thanks in advance
