ESP32 Forum

jgustavoam wrote: ↑

Tue Feb 14, 2023 8:45 pm

Hi Xiaolab,

If you don't have another frequency counter or oscilloscope frequency meter, you won't be able to calibrate because you won't have a reference measurement.
The ESP32 oscillator has some limitations in the resolution of the generated signal adjustment. So you can't rely on that signal alone.
When you have a reference measurement for the calibration, the fit is empirical. Increase or decrease the variable value until you get a measurement closer to the reference value.

Thanks Gustavo.

Hi, very good code, thanks a lot.
I have the same question as it was asked around 3 times but I have not found an answer/response to that questions: I also need to measure two frequencies at the same time. Is it possible to use two input pins or what need to be doubled or is it possible at all? A code snipped for a second counter would be very nice.

Dear jgustavoam

I have programmed an DOIT ESP32 with your Frequency Counter program everything works well I can get the Frequency readout on the Serial Console. and change Frequency as well.
I just have a problem with the attached serial LCD. I have changed the address in your program to 0x27, however I dont get anything on the display. I have downloaded a simple program to the ESP32 and here does the LCD work well. The wiring hasn't been changed, so I need a push in the right direction in order to get it to work.
Are there anything I shall be aware of regarding the IDE configuration?

Thank you in advance and best regards

Peter

Hello!! Thanks a lot for this project, it's awesome ! "Best Frequency Meter ever made with ESP32" Indeed!!

However if we want to change the sampling time, "sample_time", something is missing in the equation of the frequency.

Indeed the correct equation is :
"
frequency = ((pulses + (multPulses * overflow)) / 2.0)* 1e6/sample_time ; // Calculation of frequency
"

And of course for a sample_time of 1s, 1e6/sample_time equal one.

Thanks again!!

Dear Gustava,

Problem solved. In the code was #define LCD_I2C_OFF and it should have been #define LCD_I2C_ON. Everything is working now after the change.

All the best

Peter

PeterEH wrote: ↑

Wed Oct 11, 2023 7:28 pm

Dear Gustava,

Problem solved. In the code was #define LCD_I2C_OFF and it should have been #define LCD_I2C_ON. Everything is working now after the change.

All the best

Peter

even with the LCD_I2C_ON I am not getting the display. I get only squares. But with other software lcd is working with the same connection.

Hi Sairam,

I recommend checking these items
1) Your display is LCD 16 char x 2 lines + I2C PCF8574?
2) Check the I2c Interface lines:
#define I2C_SDA 21 // LCD I2C SDA - GPIO_21
#define I2C_SCL 22 // LCD I2C SCL - GPIO_22
3) Which PCF8574 module are you using? What is the I2C address?
LiquidCrystal_PCF8574 lcd(0x3F);
4) Run the tests with I2C scanner:
viewtopic.php?t=4742

Hi you have created a best frequency meter ever in the internet. My requirements are, apart from getting frequency, I need to get duty cycle from the given code. But I can't figured out from where I can got this. Please help me to get the DUTY CYCLE as well.

Thank you in Advance

Hi Tuku,
To measure the Duty cycle, it will require many changes to the code. I am currently unavailable to help you. Sorry.

I am waiting for ur availability. I need it urgently. BTW I can wait some days . Otherwise can you pls tell where to search for in the code.. I will try my best