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ESP32C3 > SPI2 > stuck on while
Posted: Thu Dec 05, 2024 9:45 pm
by BugSimpson
Good evening,
I currently have the problem that when I want to send a byte via the SPI interface, it gets stuck in the first while loop.
just why?
What other condition must exist?
Code: Untitled.c Select all
void spiWriteByte(uint8_t data)
{
int timeout = 0;
//spi->dev->mosi_dlen.usr_mosi_dbitlen = 7;
REG_WRITE( SPI_MS_DLEN_REG, 7 );
//spi->dev->data_buf[0] = data;
REG_WRITE( SPI_Wn_REG(0), data );
//spi->dev->cmd.update = 1;
REG_SET_BIT( SPI_CMD_REG, SPI_UPDATE_bm );
//while (spi->dev->cmd.update);
while ( REG_READ( SPI_CMD_REG ) & SPI_UPDATE_bm )
{
delay(100);
}
//spi->dev->cmd.usr = 1;
REG_SET_BIT( SPI_CMD_REG, SPI_USR_bm );
while ( REG_READ( SPI_CMD_REG ) & SPI_USR_bm )
{
delay(100);
}
}
Re: ESP32C3 > SPI2 > stuck on while
Posted: Fri Dec 06, 2024 12:41 am
by MicroController
As per the TRM, the update bit is a "WT" (write-to-trigger) only bit. It doesn't represent a state which can be read.
Re: ESP32C3 > SPI2 > stuck on while
Posted: Fri Dec 06, 2024 8:26 am
by BugSimpson
As per the TRM, the update bit is a "WT" (write-to-trigger) only bit. It doesn't represent a state which can be read.
ah okay, i see it
I took these examples from the Arduino code for spi where it waits for the bit
Code: Untitled.c Select all
spi->dev->cmd.update = 1;
while (spi->dev->cmd.update);
or am I misunderstanding that?
original arduino code:
Code: Select all
void spiWriteByte(spi_t *spi, uint8_t data) {
if (!spi) {
return;
}
SPI_MUTEX_LOCK();
spi->dev->mosi_dlen.usr_mosi_dbitlen = 7;
#if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32
spi->dev->miso_dlen.usr_miso_dbitlen = 0;
#endif
#if CONFIG_IDF_TARGET_ESP32C6 || CONFIG_IDF_TARGET_ESP32H2
spi->dev->data_buf[0].val = data;
#else
spi->dev->data_buf[0] = data;
#endif
#if CONFIG_IDF_TARGET_ESP32C2 || CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3 || CONFIG_IDF_TARGET_ESP32C6 || CONFIG_IDF_TARGET_ESP32H2
spi->dev->cmd.update = 1;
while (spi->dev->cmd.update);
#endif
spi->dev->cmd.usr = 1;
while (spi->dev->cmd.usr);
SPI_MUTEX_UNLOCK();
}
Re: ESP32C3 > SPI2 > stuck on while
Posted: Fri Dec 06, 2024 1:40 pm
by MicroController
If that Arduino code does work but you only keep getting the value back you just wrote... Did you power up and un-reset the SPI peripheral first?
Re: ESP32C3 > SPI2 > stuck on while
Posted: Fri Dec 06, 2024 3:38 pm
by BugSimpson
you mean the clock for the spi unit and the reset mode disabled?
yes, I did that.
As you already said that this is a "WT" bit, why do you poll it?