problem with the counter up down

[isaac ang]

i am doing a counter up down following the link

 

http://www.engineersgarage.com/microcontroller/8051projects/up-down-counter-using-AT89C51-circuit

but it doesn’t work and the pin21 to27 seems to be outputs

is it because i missed out on something or is there anything i have to change with the coding

ps: i am still new to 8051 , i will be thankful if someone can help me out

 

thanks

[Sagar]

are you using the same schematic as mentioned there ?

the method implemented there is called as persistence of vision. so your project might be working and 7 segment leds are glowing with very less intensity. (although transistors are used there to increase source current this shouldn’t be happening). try using red gelatin or glass type material to overlay 7 segment.

[isaac ang]

i change the display and now all four is displaying 9999

but when i try to press the up or down switch it won’t respond 

after a short time the display just goes off by itself

 

btw i used keil to create the hex file

[isaac ang]

sry i found out i did the hex file wrongly

but after i fixed the hex file

the display still doesn’t display anything

it seem there is a warning :

”   *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS

            SEGMENT: ?PR?DELAY?PROGRAM_TO_MAKE_A_UP_DOWN_COUNTER       “

i tried adding “interrupt 0” behind “void delay()”

and the warning was solved

but when i burn it into my ic the burner’s buzzer triggers’ 

it couldn’t work when i put it into the circuit 

 

can anyone tell what is wrong and what am i suppose to do

[isaac ang]

the counter somehow manage to work

but the digit jumps too far, for example from 1 to 4

can anyone tell me how to stabilize it

and let it go by the count 0-1-2-3-4…

[Author]

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