Hi,
My project is not compact, but very accurate and stable.
In fact, it uses one external DVM.

https://www.elektormagazine.com/labs/es ... -voltmeter

Hi , this is my suggestion. Generate 32768 Hz with LED PWM. And then connect this pin to RTC External Clock input. It's possible? I think so. It's accurate? I don't know. Arduino Code : long frequencia = 32768; // frequencia em Hz long canal = 1; // canal gerador de sinal long resolBits = 2; // bits...

Hi Kfine, I tested the pulse count using the ESP32 64-bit timers and actually found some delay caused by the interruptions ( up to 2.5us) See this Arduino code. I think you can make some changes to measure external intervals. https://esp32.com/viewtopic.php?f=2&t=15753 /* Measures the frequency of a...

Hi Aidin,
Your Scope is inadequate do capture the signal generated by the your program!!
The ESP32 clock ís too fast to your 20 MHz scope. Test with another fastest scope.
The irregular image is normal, because you are using under sampling frequency.

Hi, The highest frequency you can produce with the ESP32 is 80 Mhz. Internally, there are many frequency options of 160, 240, 560 Mhz or WIFI. But so far, I find it impossible to drive more than 80 MHz to the outside world. I2S0 Clock (master clock) up to 80MHz derived from APLL clock https://esp32....

Hi, I made some changes to improve accuracy and stability of the readings. Unfortunally, the interrupt handler function delays the count. So, the maximum accurate frequency reading is about 98 KHz. But bellow that frequency, the accuracy is very satisfactory. Minimum frequency is about 8 Hz. Enjoy i...

Hi, This code (part of sketch) was tested and running OK. Comments in portuguese. #include "driver/pcnt.h" // Biblioteca de pulse count #define PCNT_FREQ_UNIT PCNT_UNIT_0 // Unidade de Pulse Count 0 #define PCNT_H_LIM_VAL 10000 // Limite superior de contagem 32767 #define PCNT_INPUT_SIG_IO 4 // Puls...

Hi , I found this project: https://github.com/smurf0969/ESP32_ESP8266_WiFi_Speaker_OLED In the I2S example of IDF firmware: https://github.com/espressif/esp-idf/blob/master/examples/peripherals/i2s/main/i2s_example_main.c #define I2S_BCK_IO (GPIO_NUM_13) connect to PCM5102 BCK ( serial clock) #defin...

Hi Jakobsen,
I'm glad if my experiments helped you.

Commodore 64 was my first computer! I have C64 and C128 until today!
Regards,
Gustavo

Hi Jacobsen, " APLL control looks like some IP hooked up on internal I2C " You are wrong. APLL clock is configured by dividers that controlled by registers. Only that. I think it is possible to fine adjust frequency on the fly. But I don't know if it is real. You will certainly have some jitters whe...