Sounds like a task well suited for the RMT peripheral using DMA. That's a good suggestion. I tried and the RMT peripheral does sample the signal nicely. However, we are using the ESP32 which doesn't support DMA for the RMT peripheral, so we can only sample a max of 512 cycles (high/low) which is no...

chegewara wrote: ↑

Mon Sep 23, 2024 2:42 am

Did you try to do sampling on second core, or even better to use second core only for sampling task?

How would I do this? The work is done in the input capture interrupt callback (as set by "mcpwm_capture_channel_register_event_callbacks"). How would I set which CPU this is done on?

Hi, We have an ESP32 project which uses Bluedroid to implement some services (BLE, plus a Bluetooth classic serial port). The BLE advertises some services, and also we support connections for a BT classic serial port. We also have a data sampling task which has to (periodically) sample from a digita...

I have finally found a solution to this problem. I have been able to add extra compiler flags with (for example): target_compile_options(${COMPONENT_LIB} PRIVATE -Wunused-function -Werror) However, it didn't work for some errors (such as unused function) because the ESP-IDF build system had already ...

Hi. Thanks for the reply. Yes, I think you are correct. I'm guessing that there is some small noise in the signal which causes the edge capture input to trigger several times when it is close to the threshold, e.g. instead of just Low -> High, it goes Low -> High -> Low -> High. Each of these captur...

Hi, I've set up my ESP32 (WROVER board) to capture the rising and falling edges from a signal which is varying between 2 KHz and 4 KHz. I want to capture edge times and also whether the edge was rising or falling. I have the code working, but the edge value ( event_data->cap_edge ) in the interrupt ...

@davidribeiro Interesting result... I suspect SYSCON.saradc_ctrl2.meas_num_limit isn't implemented, which is why it is reserved (i.e. the ADC will always reset after N samples due to hardware limitations). FIX / WORKAROUND: I have found a hacky work-around which is working well for us so far: * Modi...

Any update to this? Has anyone had success by setting "SYSCON.saradc_ctrl2.meas_num_limit = 0" as @ESP_Sprite suggested?

This did not work for me - the ADC "conversion done" callback doesn't occur if the bit is set to 0.

I have tried setting this bit to 0 (by modifying the code in adc_ll.h ), but then the ADC didn't work at all (at least, when using the ADC API, I did not receive the "on_conv_done" callback). It may be worth experimenting some more. However, the TRM does say that the 0 value for this bit is reserved...

UPDATE: I found this in esp32\include\hal\adc_ll.h : #define ADC_LL_DEFAULT_CONV_LIMIT_EN 1 #define ADC_LL_DEFAULT_CONV_LIMIT_NUM 10 These settings are used to set bits in register APB_SARADC_CTRL2_REG: APB_SARADC_MAX_MEAS_NUM (8 bit) APB_SARADC_MEAS_NUM_LIMIT (1 bit). According to comments in the ...