MIDI

I would like to know it also. would  like to know the routines for 31.25kbaud serial comunication

The hardware USART library in the contributors section will handle the 31.25kbaud rate.   You will need to set the values in the setup sub, like the Rx, Tx pins, and  the SPBRG, BRGH bits.  Checking the UART/USART section of the device data sheet, table values are given for the SPBRG and BRGH bits.  Use those bits which will give the least amount of error for your speed and osc.

The header file will need to be copied/pasted into a blank "xxxx.h" file in the include folder.

What is in your program in line 30?

It's right out of the posting for the usart:

'Filename: test_usart.txt
'A program to test serial communications

'Chip model
#chip 16F690, 8
#config INTRC_OSC_NOCLKOUT, WDT_OFF

#include "usart.h"
'Hardware USART constants

'Main routine
ADOFF 
dir PORTC.7 out
SetupSerial '9600 baud, 8/N/1 no flow control

Main: 
SET PORTC.7 ON
TransmitSerial_Print("Please type in a character ")
Transmitserial(13)
Transmitserial(10)
Loopx:
Character = ReceiveSerial
If flags.gotnewdata OFF then GOTO Loopx
TransmitSerial_Print("Message received, you entered a: ")
TransmitSerial(Character)
Transmitserial(13)
Transmitserial(10)
Set flags.gotnewdata OFF
SET PORTC.7 OFF
wait 25 ms
goto Main 

Line 30 is the "wait 25 ms"

Here;s the usart.h:

' Filename: usart.h
' Hardware USART routines for Great Cow BASIC
' Steve Bell

' February 3, 2007

'Subs
' sub SetupSerial Setup serial port with baudrate 9600 for 8Mhz clock
' sub ReceiveSerial(data) Receive data from serial port into byte data
' sub TransmitSerial(data) Transmit data to serial port
' sub TransmitSerial_Print(PrintData$) Transmit a string to the serial port

'Hardware USART constants
#define GOTNEWDATA 0 'bit that indicates new data received

sub SetupSerial
ADOff 'make port digital
DIR PORTB.7 OUT
DIR PORTB.5 IN
SPBRG = 12 ' this value is for 9600 baud with brgh bit = 0 P16F690
TXSTA = b'00100000' 'note, bit 2 is BRGH
RCSTA = b'10010000' 'enable serial port and reception
SET FLAGS.GOTNEWDATA OFF
end sub

sub TransmitSerial(xmitdata)
LoopTransmit:
IF PIR1.TXIF OFF THEN goto LoopTransmit 'check if transmitter is busy
TXDATA = xmitdata
' CalcParity(TXDATA) 'calculate parity
' rotate ParityByte RIGHT 'get parity bit into status.c
' SET TXSTA.TX9D OFF 'set parity bit to zero
' IF STATUS.C = 1 THEN SET TXSTA.TX9D ON 'if status.c is one, set parity bit
TXREG = TXDATA 'transmit data
end sub

sub TransmitSerial_Print(PrintData$)
PrintLen = PrintData(0)
if PrintLen = 0 then exit sub
'Write Data
for SysPrintTemp = 1 to PrintLen
TransmitSerial(PrintData(SysPrintTemp))
next
end sub

sub CalcParity(Temp) 'calculate even parity bit, data starts in paritybyte
'result is in Lsb of ParityByte
Paritybyte = Temp 'get data for parity calculation
rrf Paritybyte,W 'rotate
xorwf Paritybyte,W 'compare all bits against neighbor
movwf Paritybyte 'save
rrf ParityByte,F 'rotate
rrf ParityByte,F 'rotate
xorwf ParityByte,F 'compare every 2nd bit and save
swapf ParityByte,W 'rotate 4
xorwf ParityByte,F 'compare every 4th bit and save
end sub

function ReceiveSerial 'check if data received, and if so, return data
IF PIR1.RCIF OFF THEN GOTO endreceiveserial
IF RCSTA.OERR ON THEN ErrSerialOverr 'if overrun error occured, handle error
IF RCSTA.FERR ON THEN ErrSerialFrame 'if framing error occurred, handle error
' for non-parity just use this below
ReceiveSerial = RCREG
SET FLAGS.GOTNEWDATA ON
GOTO successreceiveserial
' for parity checking use this
' ParityBit = RCSTA.0 get received parity bit and save
' RxData = RCREG get received data
' CalcParity(RxData)
' rotate ParityByte RIGHT get parity bit into status.c
' IF STATUS.C = ParityBit THEN
' SET FLAGS.GOTNEWDATA ON indicate got new data
' ReceiveSerial = RxData
' GOTO successreceiveserial
' END IF
' ErrSerlParity then parity is different, error
endreceiveserial:
ReceiveSerial = 0 
successreceiveserial:
end function

sub ErrSerialOverr 'error because OERR overrun errr bit is set
'this code simply clears and continues
SET RCSTA.CREN OFF
SET RCSTA.CREN ON
end sub

sub ErrSerialFrame 'error because FERR framing error bit is set
movf RCREG,W 'discard received data that has error
movf RCREG,W
movf RCREG,W
end sub

sub ErrSerlParity 'error because parity bit is not correct
end sub

I have no erros compiling your code, just copy usart.h to GCBASIC/include folder and used the #include this way:

#include <usart.h>

I don't know if the library or the code works, but it compiles Ok for me. Hope it's just the #include issue.

If I change the include statement as you indicate, I now get these errors:

midi-serial.gcb (14): Error: Syntax Error
midi-serial.gcb (18): Error: Array/Function TRANSMITSERIAL_PRINT has not been declared
midi-serial.gcb (18): Error: Syntax Error
midi-serial.gcb (19): Error: Array/Function TRANSMITSERIAL has not been declared
midi-serial.gcb (19): Error: Syntax Error
midi-serial.gcb (20): Error: Array/Function TRANSMITSERIAL has not been declared
midi-serial.gcb (20): Error: Syntax Error
midi-serial.gcb (24): Error: Array/Function TRANSMITSERIAL_PRINT has not been declared
midi-serial.gcb (24): Error: Syntax Error
midi-serial.gcb (25): Error: Array/Function TRANSMITSERIAL has not been declared
midi-serial.gcb (25): Error: Syntax Error
midi-serial.gcb (26): Error: Array/Function TRANSMITSERIAL has not been declared
midi-serial.gcb (26): Error: Syntax Error
midi-serial.gcb (27): Error: Array/Function TRANSMITSERIAL has not been declared
midi-serial.gcb (27): Error: Syntax Error

I've installed GCBasic on 2 PC's this week and I get the same result on both, so perhaps I've missed something. I used the installer then copied the files from the update.zip into the GCBasic folder.

...Dave

I have that problem sorted out. I had my suart.h file in the include/lowlevel folder where the original was. Moving it to the include folder solved the compile problem.

Now I'll modify it to work for 31250 baud.

I made the following changes to usart.h to work with a 20MHz 16F877A:

sub SetupSerial
ADOff 'make port digital
DIR PORTC.7 IN
DIR PORTC.6 OUT
SPBRG = 9 ' this value is for 31250 baud with brgh bit = 0 P16F877A 20MHz
TXSTA = b'00100000' 'note, bit 2 is BRGH
RCSTA = b'10010000' 'enable serial port and reception
SET FLAGS.GOTNEWDATA OFF
end sub

Using the following code, I'm able to display data coming from a midi controller keyboard:

'Filename: test_usart.txt 
'A program to MIDI communications 

'Chip model 
#chip 16F877A, 20 
#config OSC =HS
#config WDT = OFF 

#include <usart.h> 
'Hardware USART constants 

'Main routine 
 
SetupSerial '31250 baud, 8/N/1 no flow control

'LCD connection settings
#define LCD_IO 4 
#define LCD_DB4 PORTB.4 
#define LCD_DB5 PORTB.5 
#define LCD_DB6 PORTB.6 
#define LCD_DB7 PORTB.7 
#define LCD_RS PORTB.0 
#define LCD_RW PORTB.1
#define LCD_Enable PORTB.2

'Show opening message
CLS
PRINT "MIDI Light"
locate 1,0
PRINT "Controller"

Wait 5 s
CLS 

Main: 
 

Loopx: 
Character = ReceiveSerial 
If flags.gotnewdata OFF then GOTO Loopx 

If Character <> 254 then
LCDHex(Character)
Print ","

end if
clearflag:
Set flags.gotnewdata OFF   
 
goto Main 

It seems to regularly send a byte value of 254, which I'm ignoring.

Now I'm working on checking for Note On/ Note Off commands and getting the next two data bytes to process and toggle a port bit to control an LED based on the note pressed.

I'm making progress.....

I can capture the Note On commands and display it and the next 2 data bytes that go with it:

'Filename: test_usart.txt 
'A program to MIDI communications 

'Chip model 
#chip 16F877A, 20 
#config OSC = HS, WDT = OFF, LVP = OFF, CP = OFF
#config BODEN = OFF
 

#include <usart.h> 
'Hardware USART constants 

'Set up Key map
#define C1 PORTD.1
DIR C1 Out

Set C1 Off

'Main routine 
 
SetupSerial '31250 baud, 8/N/1 no flow control

'LCD connection settings
#define LCD_IO 4 
#define LCD_DB4 PORTB.4 
#define LCD_DB5 PORTB.5 
#define LCD_DB6 PORTB.6 
#define LCD_DB7 PORTB.7 
#define LCD_RS PORTB.0 
#define LCD_RW PORTB.1
#define LCD_Enable PORTB.2

'Show opening message
CLS
PRINT "MIDI Light"
locate 1,0
PRINT "Controller"

Wait 5 s
CLS

CLS
Main: 
 

    Loopx: 
    Character = ReceiveSerial 
    If flags.gotnewdata OFF then GOTO Loopx 
        locate 0,0
        Print(Character)
       
        If Character > 143 and Character < 160 then 'if Keyon, get rest of data
            locate 1,0
            Print("                ")
            locate 1,0
            Print(Character)
            Print ","

            Set flags.gotnewdata OFF
            Loopx1: 
            Character2 = ReceiveSerial 
            If flags.gotnewdata OFF then GOTO Loopx1
                Print(Character2)
                Print ","

                Set flags.gotnewdata OFF
           
            Loopx2: 
            Character3 = ReceiveSerial 
            If flags.gotnewdata OFF then GOTO Loopx2
            Print(Character3)

end if

clearflag:
Set flags.gotnewdata OFF

 
goto Main 

Now I need to turn a port bit on or off depending on the values. As soon as I add another if statement before the Endi If, I get compile errors for lines that compile fine before I add another if statement.

Is there a limit to the number of if statements? It also only wants a single End If no matter how many If's there are.

Any input on how to streamline the reception of the 3 data bytes and then be able to test and toggle data port bits would be appreciated.

I've been able to get it to work using Case statements and have it working for decoding 8 keys for now.