Why does spi_trans not finish?
Posted: Thu Sep 19, 2019 10:58 amHi,
i want to send a specific 32bit command via SPI (using the IDF).
The code below works (oscilloscope shows it) but I need to have cpha = 1.
So the working code is:
spi_config.interface.cpha = 0; // <- infinite loop in spi_trans if I switch to 1 here, 0 works
and not working, but I need:
spi_config.interface.cpha = 1;
This does not work and spi_trans never finishes. On the oscilloscope the stream of transmission is endless. I am a bit confused why this is the case ? How can I send a simple 8Bit command with cpha = 1? What am I missing ?
Thanks for your help.
Kind regards
Frank
i want to send a specific 32bit command via SPI (using the IDF).
The code below works (oscilloscope shows it) but I need to have cpha = 1.
So the working code is:
spi_config.interface.cpha = 0; // <- infinite loop in spi_trans if I switch to 1 here, 0 works
and not working, but I need:
spi_config.interface.cpha = 1;
This does not work and spi_trans never finishes. On the oscilloscope the stream of transmission is endless. I am a bit confused why this is the case ? How can I send a simple 8Bit command with cpha = 1? What am I missing ?
Thanks for your help.
Kind regards
Frank
Code: Select all
static void spi_master_write_slave_task(void *arg)
{
while(true){
ESP_LOGI(TAG, "start write");
spi_trans_t trans = {0};
uint32_t data = 0xAAFFAA55;
trans.mosi = &data;
trans.bits.val = 0;
trans.bits.cmd = 0;
trans.bits.mosi = 32;
spi_trans(HSPI_HOST, trans);
ESP_LOGI(TAG, "end write");
vTaskDelay(1000 / portTICK_RATE_MS);
}
}
Code: Select all
void app_main(void)
{
ESP_LOGI(TAG, "init spi");
spi_config_t spi_config;
spi_config.interface.val = SPI_DEFAULT_INTERFACE;
spi_config.intr_enable.val = SPI_MASTER_DEFAULT_INTR_ENABLE;
spi_config.interface.bit_tx_order = 0;
spi_config.interface.bit_rx_order = 0;
spi_config.interface.cpol = 0;
spi_config.interface.cpha = 1; // <- infinite loop in spi_trans if I switch to 1 here, 0 works
spi_config.intr_enable.val = SPI_MASTER_DEFAULT_INTR_ENABLE;
spi_config.mode = SPI_MASTER_MODE;
spi_config.clk_div = SPI_2MHz_DIV;
spi_config.event_cb = NULL;
spi_init(HSPI_HOST, &spi_config);
xTaskCreate(spi_master_write_slave_task, "spi_master_write_slave_task", 4096, NULL, 10, NULL);
}