There is an example of pre-transfer callback in \esp-idf\examples\peripherals\spi_master There is also a post-transfer callback as well that you can setup to tell you when the transfer is complete. http://esp-idf.readthedocs.io/en/latest/api-reference/peripherals/spi_master.html Thanks for the repl...

I have been able to write code that sends out SPI data using DMA... however I can not figure out how to get it to interrupt me to tell me its done with the transfer, right now it waits for completion.....

I used this code for my example https://github.com/natanaeljr/esp32-SPIbus

RichardS.

Ah, the Arduino SDK uses its own drivers, unfortunately I don't really know how those work. Also, moved this topic to the Arduino subforum. No problem, I have figured it out by writing my own driver for it within the Arduino IDE, I found someone with some fairly simple code to control the SPI... ht...

BTW I have both I2S peripherals running with DMA at the time of this test.

And it is using the Arduino IDE also.

RichardS

Oscilloscope :=)

I did something like for testing:

uint8_t i = 0x55;
while(1) {
hspi->transfer(i);
}

there were gaps every 8 bits...

You are saying it should be fluent? If I sent say...

uint8_t array[100];
int i = 0;
while(++i != 100) {
hspi->transfer(array);
}

no gaps??

RichardS

There are very few things you can safely call in an ISR, as it runs outside of the task context. Most notably, FreeRTOS functions ending in FromISR can be called, and the standard way of dealing with this is to have a semaphore or queue plus a thread blocking on that. The ISR can then put something...

Right now it seems when I send SPI data it send in chunks of 8 with a gap in between.

I need a continuous stream of data no breaks or gaps,

Also, can the ESP32 send data in formats longer than 8 bits?

RichardS

Can I2S0 be used instead of I2S1??

I have swapped and it seems not to work...

RichardS