8x8 Scrolling LED display (Simple example)

[wellyboot]

Hi again, Thanks for your replys, have made a couple of alterations

1st) I noticed when the digits 1st came onto the display on the right hand side column, the left hand side column some of the LEDs lit very dimmly when they should have been off.
I have modified the 'LOOP' section of code as follows to fix this problem and speed up the scrolling a bit too.

LOOP:
FOR scroll = 0 TO 35
FOR scan = 0 TO 15
PORTC = 1
FOR counter = 0 TO 7
PORTB = leddata [counter]
PAUSEUS 1500
PORTB = 0
PORTC = PORTC * 2
NEXT
NEXT
FOR counter = 0 TO 34
leddata [counter] = leddata [counter+1]
NEXT
NEXT
GOTO START
END


2) I have improved the look of the characters in the eeprom locations as follows:

eeprom 0,[%00111110,%01010001,%01001001,%01000101,%00111110] '0
eeprom 5,[%00000000,%01000010,%01111111,%01000000,%00000000] '1
eeprom 10,[%01000010,%01100001,%01010001,%01001001,%01000110] '2
eeprom 15,[%00100001,%01000001,%01000101,%01001011,%00110001] '3
eeprom 20,[%00011000,%00010100,%00010010,%01111111,%00010000] '4
eeprom 25,[%00100111,%01000101,%01000101,%01000101,%00111001] '5
eeprom 30,[%00111100,%01001010,%01001001,%01001001,%00110000] '6
eeprom 35,[%00000001,%01110001,%00001001,%00000101,%00000011] '7
eeprom 40,[%00110110,%01001001,%01001001,%01001001,%00110110] '8
eeprom 45,[%00000110,%01001001,%01001001,%00101001,%00011110] '9

3) I have noticed that if the LM35 is too close to the PIC IC the output is higher than normal resulting in a higher temperature being displayed, the PIC IC is cold so i have no idea why this is happening. I have soldered my LM35 onto 3 wires about 4cm's from the board which seems to have corrected the problem.

Hope this covers all the bugs!

[wellyboot]

Hello

Have posted a working example of the above project on youtube:

[valdirdf]

please, it sends the project of the clock and code source.

Hi again, Thanks for your replys, have made a couple of alterations

1st) I noticed when the digits 1st came onto the display on the right hand side column, the left hand side column some of the LEDs lit very dimmly when they should have been off.
I have modified the 'LOOP' section of code as follows to fix this problem and speed up the scrolling a bit too.

LOOP:
FOR scroll = 0 TO 35
FOR scan = 0 TO 15
PORTC = 1
FOR counter = 0 TO 7
PORTB = leddata [counter]
PAUSEUS 1500
PORTB = 0
PORTC = PORTC * 2
NEXT
NEXT
FOR counter = 0 TO 34
leddata [counter] = leddata [counter+1]
NEXT
NEXT
GOTO START
END


2) I have improved the look of the characters in the eeprom locations as follows:

eeprom 0,[%00111110,%01010001,%01001001,%01000101,%00111110] '0
eeprom 5,[%00000000,%01000010,%01111111,%01000000,%00000000] '1
eeprom 10,[%01000010,%01100001,%01010001,%01001001,%01000110] '2
eeprom 15,[%00100001,%01000001,%01000101,%01001011,%00110001] '3
eeprom 20,[%00011000,%00010100,%00010010,%01111111,%00010000] '4
eeprom 25,[%00100111,%01000101,%01000101,%01000101,%00111001] '5
eeprom 30,[%00111100,%01001010,%01001001,%01001001,%00110000] '6
eeprom 35,[%00000001,%01110001,%00001001,%00000101,%00000011] '7
eeprom 40,[%00110110,%01001001,%01001001,%01001001,%00110110] '8
eeprom 45,[%00000110,%01001001,%01001001,%00101001,%00011110] '9

3) I have noticed that if the LM35 is too close to the PIC IC the output is higher than normal resulting in a higher temperature being displayed, the PIC IC is cold so i have no idea why this is happening. I have soldered my LM35 onto 3 wires about 4cm's from the board which seems to have corrected the problem.

Hope this covers all the bugs!

[GoldStar]

Wow, that is really cool. I was expecting the source code to be at least a full screen full. Good work, I have this one added to favorites

[t_mask17]

Ma'am/ Sir

I would like to see your circuit diagram or schematic diagram for your temperature sensor also the source code for this item...

I'm a newbie in PIC and I would like to use PIC16f877a

Hope you could help me pls

[wellyboot]

Hi


Take a look at the 3rd post for circuit diagram (without LM35 sensor)
take a look at 5th post for code, and 7th post for modification to code

also this line (27th) in the code:

ADCON1 = %10000101 'AN0 ANALOG I/P + right justify result

needs changing to:

ADCON1 = %10001110 'AN0 ANALOG I/P + right justify result

this will set AN0 only to analog and the rest of portA to digital, this where you connect a LM35 temperature sensor output.

I believe this code should work with a 16F877 aswel but not 100% sure

[baco1978]

Hi,

i really like the idea of a scrolling temperature display.

could somebody post the hexfile?
in the lite version the 16F872 isn't supported

thanks

[krish69]

dear wellyboot,

thanks a lot for share this application with the members..
can u modify it to a scrolling clock or both scrolling clock+thermometer??
i really need one to built...
waiting for ur reply

thanks
krish69