techristian
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Midi input using portb rx port p16f1784...to many initializing factors !!
Here is my code. It should be simple enough. Get MIDI from the MIDI interface (optoisolator and 220ohm resistor) and display the MIDI information on my 7 segment LEDS. The problem is that there are so many things to set up before I even begin !! Do I have TOO MUCH in my initialization ?? I want to use RX of PORTB for input of MIDI serial data (2 stop bits and 8 bits @ 31,250 ) Is APFCON even needed in config ? I don't see anyone using it. This is running with a 20 mhz crystal, and I have a keyboard plugged into MIDI IN to supply the MIDI data. If I can't get the UART working , I'm tempted to BIT BANG this. That's how frustrating this is. I wrote RAW serial waves way back 30 years ago, but it is only a last resort. This should be accomplished using the USART. This may or may not be my latest code, but it doesn't matter. I have added and subtracted lines of code from this for the past month and I end up back in the same place...going in circles. TXSTA isn't configured here . I know it is supposed to be configured before SPBRG? . I also had BRGH set to 1 and SPBRG set to 27h at one point, but the 20 mhz ~ nicely divides evenly, so it really doesn't matter...I think?
Here is my code. It should be simple enough. Get MIDI from the MIDI interface (optoisolator and 220ohm resistor) and display the MIDI information on my 7 segment LEDS. The problem is that there are so many things to set up before I even begin !! Do I have TOO MUCH in my initialization ?? I want to use RX of PORTB for input of MIDI serial data (2 stop bits and 8 bits @ 31,250 ) Is APFCON even needed in config ? I don't see anyone using it. This is running with a 20 mhz crystal, and I have a keyboard plugged into MIDI IN to supply the MIDI data. If I can't get the UART working , I'm tempted to BIT BANG this. That's how frustrating this is. I wrote RAW serial waves way back 30 years ago, but it is only a last resort. This should be accomplished using the USART. This may or may not be my latest code, but it doesn't matter. I have added and subtracted lines of code from this for the past month and I end up back in the same place...going in circles. TXSTA isn't configured here . I know it is supposed to be configured before SPBRG? . I also had BRGH set to 1 and SPBRG set to 27h at one point, but the 20 mhz ~ nicely divides evenly, so it really doesn't matter...I think?
Code:
#include <p16f1784.inc>
; CONFIG1
; __config 0x3FE2
__CONFIG _CONFIG1, _FOSC_HS & _WDTE_OFF & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_ON & _CLKOUTEN_OFF & _IESO_ON & _FCMEN_ON
; CONFIG2
; __config 0x3FFF
__CONFIG _CONFIG2, _WRT_OFF & _VCAPEN_OFF & _PLLEN_OFF & _STVREN_ON & _BORV_LO & _LPBOR_OFF & _LVP_ON
delay equ 0x7e
BIGdelay equ 0x7f
NUMBER equ 0x7c ; if over 80h or greater next bank
temp equ 0x7d
NUMBERhi equ 0x7b
temp2 equ 0x7a
org 0x0000
goto start
org 0x004
goto dummyINT
start
movlw b'00000000' ;MOVE ZERO TO ACC "W"orking register
movwf NUMBER
movwf NUMBERhi
movwf temp
banksel TRISA; make all outputs
movwf TRISC
movwf TRISD
movwf TRISE
movlw b'10000000'
movwf TRISA ;all outputs except bit 7
movlw b'10001111' ; RB7 is RX input
movwf TRISB ; RB0-3 i/p MIDI Ch.
BANKSEL APFCON1
movlw b'11111111'
movwf APFCON1
movlw b'00000001'
movwf APFCON2
BANKSEL SYNC
movwf SYNC
movlw 0x1
movwf CREN
movwf SPEN
banksel SPBRG
movlw 0x9 ;baud 31250 for MIDI @20MHZ
movwf SPBRG
movlw b'10010000' ; async rx 8 bit
movwf RCSTA
clrw
;3600= 0E10H
BANKSEL 0
goto firstZERO ;display MSB zero at beginning
loop NOP
rxdata btfss PIR1,RCIF ; test for incoming data
goto $-1
movf RCREG,0
movwf NUMBER ;MIDI VALUE IS PASSED TO "NUMBER" FOR DISPLAY ON 7 SEGMENT LEDS
..............................................................DISPLAY BELOW
aftrHI movf NUMBER,0
movwf temp ;copy number to temp here
movlw b'00001111' ;least signifigant digit mask
andwf temp,0
CALL hexTable
movwf temp
andwf b'00111111'
movwf PORTA ;DISPLAY LOW DIGIT
movlw b'01000000'
andwf temp,1
LSRF temp, 1
LSRF temp, 1
LSRF temp, 1
LSRF temp, 0
movwf PORTE
movf NUMBER,0
movwf temp
movlw b'11110000' ;high bit mask
andwf temp, 1
LSRF temp, 1
LSRF temp, 1
LSRF temp, 1
LSRF temp, 0 ;shift right 3 times store in W
CALL hexTable
movwf PORTC
;loop forever
goto loop
hexTable BRW
RETLW b'01110111' ;0
RETLW b'01000001' ;1
RETLW b'00111011' ;2
RETLW b'01101011' ;3
RETLW b'01001101' ;4
RETLW b'01101110' ;5
RETLW b'01111110' ;6
RETLW b'01000011' ;7
RETLW b'01111111' ;8
RETLW b'01001111' ;9
RETLW b'01011111' ;A
RETLW b'01111100' ;B
RETLW b'00110110' ;C
RETLW b'01111001' ;D
RETLW b'00111110' ;E
RETLW b'00011110' ;F
PAUSE movlw 0xA4
MOVWF BIGdelay
D250 movlw 0xFE
movwf delay
l250 decfsz delay,f
goto l250
DECFSZ BIGdelay,f
GOTO D250
return
................................................HIdisplay (3RD DIGIT NOT NEEDED FOR MIDI only 2 hex digits needed)
HIdisplay INCF NUMBERhi,1
firstZERO movf NUMBERhi,0
movwf temp ;copy number to temp here
movlw b'00001111' ;least signifigant digit mask
andwf temp,0
CALL hexTable
movwf PORTD
goto aftrHI
dummyINT retfie
end
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