SPI Maximum speed
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Re: SPI Maximum speed
Note the crystal doesn't really matter; the ESP32 normally uses a PLL to derive the CPU frequency from this, then divides the CPU frequency by an applicable number to get the 80MHz APB clk.
- Vader_Mester
- Posts: 300
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Re: SPI Maximum speed
Why did I forget about the GPIO MUX?anakyr wrote:I'm 100% sure that I have a 40MHz crystal. Check attachment too. I will try first to include SPI_DEVICE_NO_DUMMY in order to ignore this checking, as the error message in red is saying. If it doesn't work, I will go to the registers
You can route your SPI directly to pins without using the GPIO MUX matrix, so with it you can achieve higher speeds. I think all your answers are in fact in the red warning message.
Code: Select all
task_t coffeeTask()
{
while(atWork){
if(!xStreamBufferIsEmpty(mug)){
coffeeDrink(mug);
} else {
xTaskCreate(sBrew, "brew", 9000, &mug, 1, NULL);
xSemaphoreTake(sCoffeeRdy, portMAX_DELAY);
}
}
vTaskDelete(NULL);
}
Re: SPI Maximum speed
Thanks a lot for the answers. Using this dummy flag I was able to produce 40 MHz at the MOSI.
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