Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Problem with LCF meter

Status
Not open for further replies.
hi,
The 'cap waiting timing' indicates that the 628A is running OK.

Check RB6 input pin , you should see a square wave, try it both when in Cap and Ind mode selection.

yes the RB 6 port is giving square wave output in cap and ind mode, I found out that the crystal oscillator I'm using is not 3.276Mhz but its 3.579Mhz as the former is not available here.Can this be a possible reason?View attachment 63778View attachment 63778

another information that the compiler is giving is "controller received command while busy > source LCD' maybe the lcd is sending acknowledgement in wrong time?
 
Last edited:
hi,
That difference in crystal frequency will give an incorrect value reading, but it should display the error value.

On your simulator can you use a signal generator to inject a signal into RB6, try 1KHz or 10KHz.?? This should display on the LCD.

Recheck your wiring against this image.
 
Last edited:
I found an interesting thing.I am using a JHD162A 16*2 LCD based on HD44780 architecture. Now in my simulation I am using LM016L LCD module that was previously working in 130kHz frequency. As soon as I changed the frequency to 3Mhz and the simulation jump-started to work perfectly. But coming to the main part, I could change the frequency of the LCD simulation but what about the hardware? can you tell how I can change the working frequency of LCD display so that it can work in sync with the MCU?? :D
 
I found an interesting thing.I am using a JHD162A 16*2 LCD based on HD44780 architecture. Now in my simulation I am using LM016L LCD module that was previously working in 130kHz frequency. As soon as I changed the frequency to 3Mhz and the simulation jump-started to work perfectly. But coming to the main part, I could change the frequency of the LCD simulation but what about the hardware? can you tell how I can change the working frequency of LCD display so that it can work in sync with the MCU?? :D

The LCD HD44870 doesn't have a sync to PIC frequency, the PIC determines the control of the LCD using the program in the PIC and its delays.

To get accurate results in the hardware you must use a 3.2768MHz crystal, if you use a different frequency you will have to change the program.
 
I'm using MPLAB X ide with MPASM 5.23 compiler. Please let me know what change do I need to make in the .asm file. I found that __CONFIG h'3F21' relates to some external crystal.
 
Hi guys ihave made this LCF 2 time there was big mitake in PCB diagram
i have modifide and now its working
ilike to shear with others
 

Attachments

  • LCF.rar
    516.8 KB · Views: 249
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top