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LCD not working

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wfv8812

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Right now i was trying to build a digital capacitance meter. After i connect all the component to the project board, the LCD was not working. There have voltage supply 5V at the pin2 when check with the multimeter but the LCD just not on and the LCD was working when connect to my friend circuit.

Below is my circuit diagram.

Please help me.....
Thank You.
 

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Your schematic doesn't show anything obvious. Can you post a photograph of your completed unit?
 
Are you still having problems with this?

Most of the time the lcd will power up, but with a row of 'blocks' on row 1. this means power is getting to it, but it has not been configured properly. If it is completely blank (even as you turn the pot from zero to full scale) then this would indicate something more serious
 
Hi,
Have you noticed that the schematic connections on the LCD go 1 2 3 4 6 5 etc and not 1 2 3 4 5 6 as expected?

Maybe they are transposed in your build?

Just a thought............Al
 
Are you still having problems with this?

Most of the time the lcd will power up, but with a row of 'blocks' on row 1. this means power is getting to it, but it has not been configured properly. If it is completely blank (even as you turn the pot from zero to full scale) then this would indicate something more serious

My one was not shown the row of the block, the light also not showing up. The lcd just completely off and not respond. But in the simulation of proteus, this circuit was showing it can work.
 
Are you sure you are wiring to the correct pins? They should be labelled 1 at one end and 14 (or 16) at the other depending on if it has a backlight. Apart from that, jsut power the backlight on its own - it should still work without any software intervention. Aside from that, if it is all wired correctly, it sounds broke. Go back and put it in your friends circuit and see if it still works
 
Sometimes on your control signals, just the way you have it soldered can throw a phase shift onto a pin. Try taking a .01uf cap and place it across each one of the control signals to ground while it is running and see if it causes the characters to show up.
 
Today, i had try connect the pin 15 & 16 and the backlight of the LCD was on, but it still don have anything, the row of the block. What should i do ?

Is there have any different from the parallel LCD and the normal LCD?
 
I am not an expert in assembly, I usually do all my code in PBP but the only thing that caught my eye is your R/W on Port RB1, you have it set to read and cleared to write.
See line 197 as an example
Code:
BCF      PORTB, 1	; Clear R/W to write
I am 99.9% sure it should be the opposite.
PORTB,1 should be = 0 to read and 1 to Write.

Maybe an expert can confirm!
 
Wfv8812,

You are not getting much response here, I would suggest you validate your code on
Microchip Forum as for your circuit, if you followed it precisely I think it is ok.

Would be nice if when you do get your answer that you post it here to complete the thread.

Mike
 
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