[SOLVED]No output on LCD screen of green bee project.

comnwrt:                      	;send command to LCD
	MOV LCDDATA, A		;copy reg A to port1
	CLR RS			;RS=0 for command
	CLR RW			;R/W=0 for write
	SETB E			;E=1 for high pulse
	MOV R3,#50
REG_3:	
	MOV R4,#255
	DJNZ R4,$
	DJNZ R3,REG_3
	CLR E			;E=0 for H-to-L pulse 
	RET


datawrt:                    ;write data to LCD
      MOV LCDDATA, A    ;copy reg A to port1 
      SETB RS            ;RS=1 for data
      CLR RW      		;R/W=0 for write
      SETB E			;E=1 for high pulse
	  MOV R3,#50
REG_4:
	MOV R4,#255
	DJNZ R4,$
	DJNZ R3,REG_4
	
    CLR E			;E=0 for H-to-L pulse
    RET    


lcddelay:			;Delay routine for LCD
	MOV R3, #50   
here2:MOV R4, #255  
here3:DJNZ R4, here3 ;stay until R4 becomes 0
	DJNZ R3, here2
     RET

as u see here itz only mention in d coment part.

can you attach the code here?

sir here is d file .......u asked.

the code is fine.. in the schematic, P0.0 is connected to D7 i guess and P0.7 connected to D0. which means they are inverted or connected wrongly. Please make them
P0.0 to D0
to
P0.7 to D7

I am sure you will see what you want on LCD.

r u sure sir, coz some hs advice me b4 dat. oky den i will chk it. n reply u very soon.

the code is fine.. in the schematic, P0.0 is connected to D7 i guess and P0.7 connected to D0. which means they are inverted or connected wrongly. Please make them
P0.0 to D0
to
P0.7 to D7

I am sure you will see what you want on LCD.

Ajay

Thanks a lot Ajay sir :-). u noticed d exact pt. i changed connection n my LCD starts working !dance ............ i chk out no of results on it. den i discoverd uC is nt fetching out updates 4m ADC. i think der is som problem in connection in between ADC n uC. i dnt know wht exactly happening wid it. after connecting every sensors 2 ADC , itz showng default values on LCD. n also d mode change is nt working , means itz nt showing d actuators status . even at ambient condition uC showing d exteam high(HOT) n extream low(cold) contion results. it think der is prob in P1 n P3 section. i need some more research on it 2 find out the exact fault.

1. Default

2. LOWest values

3.High

4.Higher

5.Extream condition


i will reply 2 thread wid my next researchs......

till den bye gdnt.

Hey,
Sorry for coming in so late. I am a bit busy cos of an internship I have just got and it is a disaster of sorts!
Coming to the project, firstly I must say am so happy to see it working feels great!!!

I did not understand what exactly is the problem u are facing now?
Regarding the mode switch please check if the interrupt code is right. Starting from the masking/ unmasking to the ISR.
Regarding the sensors, are all of them behaving like this or just the temp sensor? Does the o/p vary (fluctuate) by itself without you changing the temp around the LM35?
First tell me have you checked each sesnor's voltage o/p individually? Do they give you correct outputs? If yes then have you checked the o/p of the ADC for each sensor individually in stand alone mode?
I have not been following your progress here that is why I am asking. If you have done both these things and got the exact o/p then there seems to be a serious mistake in my code!

hello amit ,
good 2 see u alfter long tim..... n belated happy holi......

coming to the project.
1.i hv chked every sensors manualy......n de r working perfectly, i m getting exact voltage output on multimeter according 2 the atmospheric condition.
2. i hv nt chk d ADC ouput 4 sensors in stand alone mode.
3. i m using AT89c52 , insted of using AT89s52.....means i m using preceder one.
4.o/p of LCD is nt fluctuating, itz showing values constantly. whn turn off ckt n on it again itz showing another o/p constanly, bt nt varing timly i mean to say itz nt showing d intant readings of sensors.
5. if i turn off d power only to ADC ckt(nt d Uc ckt) , den in disply itz showing

and if i on d ADC ckt , itz showing d defalut value.
Note: Itz also d same o/p if i only give power 2 uC ckt without interfacing the ADC wid uC ckt.

so i hv no idea whr is d fault........i hv tried my best 2 expalin d things....i hope u will reply me soon

Hey. Thanks and happy holi to you too.
See you should always go step by step otherwise detecting the error will be a herculean task. Now you know the sensors are right. Next you need to know if your ADC is working! Have you tested it? Do you know what kind of o/p is it giving? Do this:
1. Run the ADC in stand alone mode. Connect 1 sensor to it (LM35 should be the easiest) Give the requisite control signals and check the digital o/p. Is it matching to the analog i/p?
2.This way check all the 4 i/p pins of the ADC that you are using. If it works fine till here then please try the other 3 sensors also individually (at any 1 i/p pin should suffice).
3. If this is also right then check the look up table. For any 1 of the digital o/p you got what is the value stored in the LUT which will be displayed?

You said the screen does not change at all after the data is 1st displayed, right? Look at it closely, can you see the cursor moving below at regular intervals?
Have you been able to correct the problem with the mode display switch?

hello amit..

i also feel d same, need 2 chk every sensor in stand alone mode. bt i hv never done dis b4, i dnt hv any bred board only i hv a multimeter, so i vh no iead hw 2 run ADC in stand alone mode.

If this is also right then check the look up table. For any 1 of the digital o/p you got what is the value stored in the LUT which will be displayed?

I ddnt get u on d over quote, n Wht is dat Look up Table.

You said the screen does not change at all after the data is 1st displayed, right? Look at it closely, can you see the cursor moving below at regular intervals?

yes i hv noticed dat cursor is moving.....bt itz nt showing d even room temp. dis all above readings at room temp, each tim i On d whole ckt it shows a different value.....
and abt the mode display der is another disscussion is going on in the forume chk out this link, and also reply 2 dis thread der also..as i m closeing disscussion here.

http://www.8051projects.net/forum-t19717-last.html