Charlie-plexing

[Demon]

I used the wiring above for pins D.1, D.2 and D.3 on a 16F877 and it didn't work as expected.

I get 3 LEDs blinking faintly instead of a single one. It seems as if the current loops over to the unused pin and comes back.

I'll have to check out your thread. I must be missing something.

' Blink 6 LEDs connected to Port D.1, D.2 and D.3 in charlie-plex manner

'   PIC             16F877      ext osc 20MHz
'   PBP             v2.60c
'   MPASM           v5.49
'   MCS+            v2.1.0.7
'   U2 programmer   v4.32

asm
 __config _HS_OSC & _WDT_OFF & _PWRTE_OFF & _BODEN_ON & _LVP_OFF & _CPD_OFF & _WRT_OFF & _DEBUG_OFF & _CP_OFF
endasm

DEFINE OSC 20
ADCON1 = 7                  ' Set Ports to digital
TRISA = %00000000           ' Set all Ports to output 
TRISB = %00000000
TRISC = %00000000
TRISD = %00000000
TRISE = %00000000
PORTA = %00000000           ' Set ports OFF
PORTB = %00000000
PORTC = %00000000
PORTD = %00000000
PORTE = %00000000
    pause 100
mainloop:
    TRISD = %11111001       ' Enable pins D.1 and 2
    PORTD = %00000100       ' Turn ON pin D.2 --> D.1
    pause 500
    PORTD = %00000010       ' Turn ON pin D.1 --> D.2
    pause 500

;    TRISD = %11110101       ' Enable pins D.1 and 3
;    PORTD = %00001000       ' Turn ON pin D.3 --> D.1
;    pause 500
;    PORTD = %00000010       ' Turn ON pin D.1 --> D.3
;    pause 500

;    TRISD = %11110011       ' Enable pins D.2 and 3
;    PORTD = %00000100       ' Turn ON pin D.2 --> D.3
;    pause 500
;    PORTD = %00001000       ' Turn ON pin D.3 --> D.2
;    pause 500

    TRISD = %11111111       ' All pins disabled
    pause 500
    goto mainloop
End

Robert

[Boater]

Hi AvionicsMaster1
No big deal, someone on here reckons that mistakes are not mistakes but learning opportunities and I think he's right having had plenty of learning opportunities myself.
Still getting them.
Using your idea to copy and paste |OR Demon, thanks.
Thanyou to Richard for keeping us right and for introducing me to the lookup command which has led me onto writing my code in decimal and hex.
Having great fun with them, well this is a hobby and hobbies are supposed to be fun.
The following code is for a set of traffic lights on the roads as part of a 1/76 scale model railway.

'****************************************************************
'*  Name    : Four Way Traffic Lights                           *
'*  Author  : Jim Hagan                                         *
'*  Date    : 10/07/2016                                        *
'*  Version : 1.0                                               *
'*  Notes   : For 16F84A                                        *
'****************************************************************
 #CONFIG
    __CONFIG _XT_OSC & _CP_OFF
#ENDCONFIG
  'Defines
   DEFINE OSC 4          'Tell PBP3 expected system clock frequency
  'Aliases
   LEDS1 var PORTB        'Assign name LEDS1 to PORTB
   LEDS2 VAR PORTA        'Assign name LEDS2 to PORTA
   'Variables
   i var byte
   'Initialize
   TRISB = $0            'Set PORTB to Output
   TRISA = $0
   'Program Code
START
   gosub REDGREEN
   gosub REDAMBER
   gosub GREENRED
   gosub AMBERRED
   goto START
REDGREEN
   LEDS1 = $61            'LEDS 0, 5 and 6 on PORTB On
   LEDS2 = $08            'LED 3 on PORTA On
   pause 3000             'Puts lights on for 3 seconds
   for i = 1 to 10
   LEDS1 = $0
   LEDS2 = $0
   next i
   return
REDAMBER
   LEDS1 = $D3             'LEDS 0, 1, 4, 6 and 7 on PORTB On
   LEDS2 = $04             'LED 2 on PORTA On
   pause 2000              'Puts lights on for 2 seconds
   for i = 1 to 10
   LEDS1 = $0
   LEDS2 = $0
   next i
   return
GREENRED
   LEDS1 = $C              'LEDS 2 and 3 on PORTB On
   LEDS2 = $03             'LEDS 0 and 1 on PORTA On
   pause 3000
   for i = 1 to 10
   LEDS1 = $0
   LEDS2 = $0
   next i
   return
AMBERRED
   LEDS1 = $9A              'LEDS 1, 3, 4 and 7 on PORTB On
   LEDS2 = $06              'LEDS 1 and 2 on PORTA On
   pause 2000
   for i = 1 to 10
   LEDS1 = $0
   LEDS2 = $0
   next i
   return
   end

Regards
Jim