Help Needed:Using 3 PIC 16f877A in a circuit

G

gurunz

New Member

• Apr 19, 2009

• #1

hi all, recently i made a project call dart board automatic calculator that calculate the score of dart throw. I use 3 pic since i need 64 inputs. I use a oscillator for each PIC (total 3) and a 9v power supply and a 5 v power regulator. Everything fine in simulation but when i applied on real circuit, the calculation become unstable and sometimes lcd display nonsense. I tried all the solution i know but still cant solve it. Please someone help me

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Apr 19, 2009

• #2

You've done something wrong - simulators aren't real life, so doesn't mean it will really work.

But you haven't posted either the FULL circuit diagram, or the source code - so no one can offer any advice on what you've done wrong.

 

G

gurunz

New Member

• Apr 20, 2009

• #3

**broken link removed**

This is my schematic.Hope someone can help me find what wrong and give advice. Thanks alot

 

gramo

New Member

• Apr 20, 2009

• #4

Not that I really want to look at it, but you should probably put your code up too..

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Apr 20, 2009

• #5

Sorry, but that is really horrible!.

You only need one PIC, you can multiplex 64 keys easily and simply on two 8 bit ports, you're making it FAR more complicated than it needs to be.

Check my tutorials, which show how to mutiplex 16 keys on a single port.

 

G

gurunz

New Member

• Apr 20, 2009

• #6

hmmmm
im confused...
if i use 1 PIC, how could i connect all 45 input to a single pic???
sshould i used encoder to be the medium between the switches and PIC???

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Apr 20, 2009

• #7

gurunz said:

hmmmm
im confused...
if i use 1 PIC, how could i connect all 45 input to a single pic???
sshould i used encoder to be the medium between the switches and PIC???

Click to expand...

Multiplexing - check my tutorial like I said - two 8 bit ports gives you 64 possible keys.

No encoder required.

 

blueroomelectronics

Well-Known Member

• Apr 20, 2009

• #8

A matrix keypad is one way.

 

G

gurunz

New Member

• Apr 20, 2009

• #9

do u mean that a single switch has to be connected to some pins???
for example SW1(means switch no1)
"when SW1 on"

if portb = 00000001
if portc = 00000001 then ......

do u mean that i should program like the above???

 

S

SPDCHK

Member

• Apr 20, 2009

• #10

For the third time "Refer to Nigel's tutorials", i.e. click and READ everything.