Tach Project (binary counting)...
Hello Everyone! I'm progressing with my Tach project. I finally have all the parts
I need at least :) Things had been progressing until I ran into this bug...
The Circuit:
I'm using a 16F877 and a Max7219. I have each individual segment attached
to the anode of a discreet LED. The cathodes are all connected common to DIGO
of the Max7219. I have 8 LED's total connected (using the DP's output too).
The Code:
I've taken code written for the Basic Stamp 2 and modified it to work with my
PicBasic Pro / hardware setup. The final version will have 32 LED controlled
by Max7219 & 16F877. Code is listed below.
The Problem:
The code will count binary up to 14. When it reaches 15 (f) or 00001111 it
completely halts and all the LED's turn off. I thought it was pulling too
much current so I ran the shiftout function with %1111111111111111/16 which
turned on all the LED successfully so I'm guessing this is not an issue of
drawing too much current.
Request:
Anyone have PicBasic Pro Code that supports the Max7219 driving LED's and
not Digits? Ideally with the 16f877 and the microcontroller. If not, I can
remap the I/O pins.
I've explored modifying the scan limit, decode mode, intensity, shutdown
mode etc. still no favorable results.
Thank you for your time,
Netjammer-
Code:
' =========================================================================
include "modedefs.bas"
' -----[ Program Description ]---------------------------------------------
' Counting binary from 0 to 1111 (want to go to 11111111 but routine halts
'& LED's turn off
' -----[ Revision History ]------------------------------------------------
' -----[ I/O Definitions ]-------------------------------------------------
'symbol MAX_Data = PORTC.5 'line for data input connected to RC5
'symbol MAX_Clk = PORTC.3 'CLK line connected to pin RC3
'symbol MAX_Load = PORTA.3
symbol DOUT = PORTC.5 'line for data input connected to RC5
symbol CLK = PORTC.3 'CLK line connected to pin RC3
symbol Load = PORTA.3 'line for Load connected to RA3
' -----[ Constants ]-------------------------------------------------------
IsLow CON 0
IsHigh CON 1
' -----[ Variables ]-------------------------------------------------------
DIG0 VAR Word
DIG1 VAR Word
DIG2 VAR Word
Value VAR byte
Ken VAR byte
' -----[ EEPROM Data ]-----------------------------------------------------
' -----[ Initialization ]--------------------------------------------------
Dig0 = $0100
Dig1 = $0200
Dig2 = $0300
Value = 0
Ken = 0
' -----[ Program Code ]----------------------------------------------------
Begin:
GOSUB DecodeMode
GOSUB ShutDownMode
GOSUB ScanLimit
GOSUB Intensity
Continue:
'the for next loop is set up to cause each digit to count up
'sequentially from 1 to 100
FOR Ken = 0 TO 100
PAUSE 500
Dig0 = Dig0 | Value
Dig1 = Dig1 | Value
Dig2 = Dig2 | Value
'first digit least significant
LOW Load
SHIFTOUT DOUT, CLK, MSBFIRST,[Dig0\16]
HIGH Load
PAUSE 40
'second digit
' LOW Load
' SHIFTOUT DOUT, CLK, MSBFIRST,[Dig1\16]
' HIGH Load
' PAUSE 40
'third digit
' LOW Load
' SHIFTOUT DOUT, CLK, MSBFIRST,[Dig2\16]
' HIGH Load
' PAUSE 40
Value = Value + 1
Dig0 = $0100
' Dig1 = $0200
' Dig2 = $0300
NEXT
Value = 0
Dig0 = $0100
' Dig1 = $0200
' Dig2 = $0300
GOTO Continue
END
' -----[ Subroutines ]-----------------------------------------------------
'Decode mode for no decoding to BCD
'Least sig nibble:
'0 = no decode
'1 = decode digit 0
'F = decode digits 0-3
'FF = decode digits 0-7
DecodeMode:
LOW Load
' SHIFTOUT DOUT, CLK, MSBFIRST,[$090F\16]
SHIFTOUT DOUT, CLK, MSBFIRST,[$0900\16]
HIGH Load
RETURN
'Set shutdown mode so device is active
ShutDownMode:
LOW Load
SHIFTOUT DOUT, CLK, MSBFIRST,[$0C01\16]
HIGH Load
RETURN
'Set scan limit mode for three digits
ScanLimit:
LOW Load
' SHIFTOUT DOUT, CLK, MSBFIRST,[$0B02\16]
SHIFTOUT DOUT, CLK, MSBFIRST,[$0B00\16]
HIGH Load
RETURN
'Set intensity of LEdDs
'LSNibble 0 = min intensity and F = max intensity
Intensity:
LOW Load
SHIFTOUT DOUT, CLK, MSBFIRST,[$0A09\16]
HIGH Load
RETURN
