multiple 7219 and 7 segment displays: trouble

guydb

this is driving me nuts...
I want to drive three separate dual 7 segment displays using 3 separate 7219 drivers (why? because the displays have to be in different locations but need to be controlled by one common stamp and because the have to be as independent of each other as possible and because the required number combinations would make the program way to long to use a single 7219 to drive 6 displays...and probably because I'm a poor coder).
The problem: for some odd reason only one dual display will light up. I've tested the circuit and separately all 3 drivers and displays work, it's just when I use them all together that 2 out of 3 refuse to function.
Here's the sample program I'm using: it should display figures 39, 17 and 34 on the three separate displays (I'm using a BS2SX). Possible redundancies have been added out of desperation. I hope somebody can tell me what I'm doing wrong (I've used Stamp controlled 7219 drivers and display in the past without any problem, but always in a single configuration.)

' {$STAMP BS2sx}

DATA_n CON 2
CLK CON 1
Load CON 0

DATA_n2 CON 5
CLK2 CON 4
Load2 CON 3

DATA_n3 CON 15
CLK3 CON 14
Load3 CON 13

decode CON 9
brite CON 10
scan CON 11
switch CON 12

temp CON 15

initmax VAR Byte
initmax2 VAR Byte
initmax3 VAR Byte

index VAR Nib
index2 VAR Nib
index3 VAR Nib

odd VAR index.BIT0


DIRS = %1111110000000111 'pins 0,1,2,3,4,5,13,14,15 as outputs

FOR index = 0 TO 7
LOOKUP index,[noparse][[/noparse]scan,1,brite,6,decode,$03,switch,1],initmax
SHIFTOUT DATA_n,CLK,MSBFIRST,[noparse][[/noparse]initmax]
PAUSE 200
IF odd = 0 THEN noLoad
PULSOUT Load,15

NoLoad:
NEXT

FOR index2 = 0 TO 7
LOOKUP index2,[noparse][[/noparse]scan,1,brite,6,decode,$03,switch,1],initmax2
SHIFTOUT DATA_n2,CLK2,MSBFIRST,[noparse][[/noparse]initmax2]
PAUSE 200
IF odd = 0 THEN noLoad2
PULSOUT Load2,15

NoLoad2:
NEXT

FOR index3 = 0 TO 7
LOOKUP index3,[noparse][[/noparse]scan,1,brite,6,decode,$03,switch,1],initmax3
SHIFTOUT DATA_n3,CLK3,MSBFIRST,[noparse][[/noparse]initmax3]
IF odd = 0 THEN noLoad3
PULSOUT Load3,15

NoLoad3:
NEXT



blank1:
SHIFTOUT DATA_n,CLK,MSBFIRST,
SHIFTOUT DATA_n,CLK,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load,15
SHIFTOUT DATA_n,CLK,MSBFIRST,
SHIFTOUT DATA_n,CLK,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load,15
PAUSE 1000

thirtynine:
SHIFTOUT DATA_n,CLK,MSBFIRST,
SHIFTOUT DATA_n,CLK,MSBFIRST,[noparse][[/noparse]9]
PULSOUT Load,15
SHIFTOUT DATA_n,CLK,MSBFIRST,
SHIFTOUT DATA_n,CLK,MSBFIRST,
PULSOUT Load,15

PAUSE 2000

blank2:
SHIFTOUT DATA_n2,CLK2,MSBFIRST,
SHIFTOUT DATA_n2,CLK2,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load2,15
SHIFTOUT DATA_n2,CLK2,MSBFIRST,
SHIFTOUT DATA_n2,CLK2,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load2,15
PAUSE 200

seventyone:
SHIFTOUT DATA_n2,CLK2,MSBFIRST,
SHIFTOUT DATA_n2,CLK2,MSBFIRST,[noparse][[/noparse]7]
PULSOUT Load2,15
SHIFTOUT DATA_n2,CLK2,MSBFIRST,
SHIFTOUT DATA_n2,CLK2,MSBFIRST,
PULSOUT Load2,15
PAUSE 2000

blank3:
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
SHIFTOUT DATA_n3,CLK3,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load3,15
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
SHIFTOUT DATA_n3,CLK3,MSBFIRST,[noparse][[/noparse]temp]
PULSOUT Load3,15
PAUSE 2000

thirtyfour:
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
PULSOUT Load3,15
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
SHIFTOUT DATA_n3,CLK3,MSBFIRST,
PULSOUT Load3,15
PAUSE 2000

END

bsparky

Not sure if this is your problem ,but when you are setting up your displays you have a pause command in your loops, but not in the third you don't need them. You might check out my completed project "Dart Display" 2nd or third page back. I'm controling to seperate 3 diget displays useing one max 7219, wire is cheaper than 7219 at $10.00 apiece. Not hard just changing the numbering in your loop. How far apart are your displays? Good luck.

guydb

thank you for your suggestions, but as usual, after phrasing the problem and giving it another thought I saw that my initialization procedure was then problem...works fine now.
I got 2 maxim samples and bought a 3rd one, so it's OK. the displays are in separate rooms.
thanks
guy