Thanks for your replies! Yes, we already checked the frequency on a spectrum analyzer and it looked good. And yes, we have a full ground plane under the crystal. And today, I removed the 40 MHz crystal and soldered a 26 MHz crystal taken from an ESP-01 on the board. Now, even scanning did not work a...

No suggestions?

Hi, we have developed a custom board based on the ESP32 (ESP32D0WDQ5, revision 0) and are facing major problems with Wifi and Bluetooth. We are not able to connect to a station or to create an access point at all. The only thing that is working is scanning for networks. For example, this project (ht...

So, today I had access to the oscilloscope again and this time I added "portYIELD_FROM_ISR" to my ISR handler so that I got the following: static void IRAM_ATTR isr_handler(void* args) { gpio_num_t gpio_num = (gpio_num_t) args; xQueueSendFromISR(intr_queue, &gpio_num, NULL); portYIELD_FROM_ISR(); } ...

I tried it a while ago and caused an exception.

Hi Angus, it is basically the GPIO example. I did a measurement again, the exact delay is 16 us. #include "esp_log.h" #include "esp_intr_alloc.h" #include "driver/gpio.h" #include "freertos/FreeRTOS.h" #include "freertos/portmacro.h" #include "freertos/queue.h" #include "freertos/task.h" #define GPI...

Hi, we are doing some stuff with an external RF transceiver and need to respond to its interrupts as fast as (technically) possible. Writing into a queue in order to handle the interrupt in another task takes way too much time (about 13 us). Setting a bit and polling this bit in another task within ...