PIC to LCD wiring problem ? - Electronic Circuits Projects Diagrams Free

pasanlaksiri · 30th September 2007, 08:43 AM

Yester day i bought a 20X4 LCD and this is a schematic for LCD Alarm clock( 20X4 ).

So my prob is

That PIC to LCD wiring is not clear to me.

Plz can some one help me plzzz..

bananasiong · 30th September 2007, 09:01 AM

Have you seen Nigel's site?
http://winpicprog.co.uk

ericgibbs · 30th September 2007, 09:10 AM

hi Pasan,
It would be helpful if you could post the program code, so that we can identify which pin is which.

art-666 · 30th September 2007, 01:04 PM

http://www.thouters.be/PicAlarmClock

coded in Jal downloads http://www.thouters.be/Downloads

pasanlaksiri · 30th September 2007, 02:31 PM

Quote:

Originally Posted by art-666

http://www.thouters.be/PicAlarmClock

coded in Jal downloads http://www.thouters.be/Downloads

Ya thats it

kerelektronik · 30th September 2007, 03:26 PM

i hope you are sure about the lcd's model is hd44780..

ericgibbs · 30th September 2007, 05:01 PM

hi,

The port pin references from the posted site shows this:

Code:

-- pin assignment for the 4-bit (6 PIC I/O pins) interface:
--
-- PIC        HD44870
-- ----------------------
--  5 Gnd      1 Gnd
-- 14 Vcc      2 Vcc
--  5 Gnd      3 Contrast 
--  6 B0      11 D4
--  7 B1      12 D5
--  8 B2      13 D6
--  9 B3      14 D7
-- 10 B4       4 RS D/I_
--  5 Gnd      5 R/W_
-- 11 B5       6 E
--
-- pin assignment for the 8-bit (11 PIC I/O pins) interface:
--
-- PIC        HD44870
-- ----------------------
--  5 Gnd      1 Gnd
-- 14 Vcc      2 Vcc
--  5 Gnd      3 Contrast
-- 17 A0       4 RS D/I_
--  5 Gnd      5 R/W_
--  1 A1       6 E
--  6 B0       7 D1
--  7 B1       8 D2
--  8 B2       9 D3
--  9 B3      10 D4 
--  6 B4      11 D4
--  7 B4      12 D5
--  8 B6      13 D6   (2k2 series resistor for ISP!)
--  9 B7      14 D7   (2k2 series resistor for ISP!)
--

It dosn't seem to make much sense when compared to the circuit.

I'm assuming the 8 bit LCD 16F877 connect list.

Where is the RS line, it says PORTA.1 in the list, also the LCD contrast is grounded??

pasanlaksiri · 30th September 2007, 05:36 PM

Quote:

Originally Posted by kerelektronik

i hope you are sure about the lcd's model is hd44780..

es it is

ericgibbs · 1st October 2007, 07:42 AM

Quote:

Originally Posted by pasanlaksiri

es it is

hi Pasan
Have you compared the table I posted [taken from that website] with your circuit diagram?

It does not match.

pasanlaksiri · 1st October 2007, 07:45 AM

Quote:

Originally Posted by ericgibbs

hi Pasan
Have you compared the table I posted [taken from that website] with your circuit diagram?

It does not match.

Ya it doesn't match. But i can take sme idea from it.

Thanks

ericgibbs · 1st October 2007, 08:01 AM

Quote:

Originally Posted by pasanlaksiri

Ya it doesn't match. But i can take sme idea from it.

Thanks

I would consider using your compiler/assembler to produce the *.hex code from the JAL files,
then using a dis-assembler to get a 'normal' source code listing.

IIRC WinPicPro [Nigel has referred to at time?], no sure, never used a PIC dis''

This should enable you to decide which PIC pins drive which LCD pins.
Also use a 10K pot on the LCD Vo Contrast.

pasanlaksiri · 1st October 2007, 01:36 PM

Quote:

Originally Posted by ericgibbs

I would consider using your compiler/assembler to produce the *.hex code from the JAL files,
then using a dis-assembler to get a 'normal' source code listing.

IIRC WinPicPro [Nigel has referred to at time?], no sure, never used a PIC dis''

This should enable you to decide which PIC pins drive which LCD pins.
Also use a 10K pot on the LCD Vo Contrast.

I think he set that display to MAX Contra.

Thanks for the advice. I'll use Preset

**Nigel Goodwin** · 1st October 2007, 01:45 PM

Quote:

Originally Posted by pasanlaksiri

I think he set that display to MAX Contra.

Thanks for the advice. I'll use Preset

Yes, use the preset - on many LCD's setting it to maximum means it doesn't work (it just gives all black squares).

pasanlaksiri · 1st October 2007, 01:54 PM

Quote:

Originally Posted by Nigel Goodwin

Yes, use the preset - on many LCD's setting it to maximum means it doesn't work (it just gives all black squares).

Yes, I also have 16X2 LCD connected to the PC. When i ground that pin Its shows only black squares

pasanlaksiri · 3rd October 2007, 10:05 AM

I have a serious problem again about Programing the PIC.

When im trying to Program ( main.hex ) the PIC its always faill to verify. My programmer is also working properly.

I set configurations as he said so.

osc hs
watchdog off
powerup on
protection off

But all ways get same error.
Then I and select XT osc. Then its verify the chip. But it doesn't work.

Y really it wont verify the chip? Is it coz of problem in the source codes

Here is the files

ASM

HEX

Thanks guys

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30th September 2007, 08:43 AM	(permalink)
pasanlaksiri	PIC to LCD wiring problem ? Yester day i bought a 20X4 LCD and this is a schematic for LCD Alarm clock( 20X4 ). So my prob is That PIC to LCD wiring is not clear to me. Plz can some one help me plzzz.. __________________ Digital Voltmeter PIC16F877 Audio CD Player My home made 2.1 System Nokia 3310 Lcd & Pic12F629 3 channel IR remote Controller Project using 12F Pic Pasan...

30th September 2007, 09:01 AM	(permalink)
bananasiong	Have you seen Nigel's site? http://winpicprog.co.uk __________________ Superman returns..

30th September 2007, 09:10 AM	(permalink)
ericgibbs	hi Pasan, It would be helpful if you could post the program code, so that we can identify which pin is which. __________________ Eric "Good enough is Perfect" PIC tutorials: Gramo's: www.digital-diy.net/ Bill's: www.blueroomelectronics.com/

30th September 2007, 01:04 PM	(permalink)
art-666	http://www.thouters.be/PicAlarmClock coded in Jal downloads http://www.thouters.be/Downloads

30th September 2007, 03:26 PM	(permalink)
kerelektronik	i hope you are sure about the lcd's model is hd44780..

3rd October 2007, 10:05 AM	(permalink)
pasanlaksiri	I have a serious problem again about Programing the PIC. When im trying to Program ( main.hex ) the PIC its always faill to verify. My programmer is also working properly. I set configurations as he said so. osc hs watchdog off powerup on protection off But all ways get same error. Then I and select XT osc. Then its verify the chip. But it doesn't work. Y really it wont verify the chip? Is it coz of problem in the source codes Here is the files ASM HEX Thanks guys __________________ Digital Voltmeter PIC16F877 Audio CD Player My home made 2.1 System Nokia 3310 Lcd & Pic12F629 3 channel IR remote Controller Project using 12F Pic Pasan...