'----------------------------------------------------- 'PUBLIC DOMAIN '----------------------------------------------------- ' 'MIDIBEATCLKIN 'dr.mabuse ' '***************************************************** '* MIDI-In interrupt or polled (set by conditional) * '* MIDI-Out polled * '* Timer interrupts provide 1mS timestamp * '***************************************************** ' ' PSIM-1 (Programmable Synthesizer Interface Module) ' Module: PSIM-1 REV1b ' Processor Type: Basic Micro - Basic Atom Pro24M ' 'DESCRPTION (by dr.mabuse) ' this is a very preliminary '1st experiment' with MIDI IN system realtime messages ' it may, perhaps be useful for synchronizing analog sequencers or ADSR's to a MIDI system 'Converts MIDI beat clock (system realtime F8) to pulses at 4 subdivisions of the bar - tested at tempo 20 thru 255BPM 'all pulses are one 32nd note wide 'CVout1 = one pulse per 16th note 'CVout2 = one pulse per 8th note 'CVout3 = one pulse per quarter note 'CVout4 = one pulse per Bar of 4/4 'no MIDI out is transmitted 'Be sure that you enable MIDI beat clock (NOT MID time code)on your sequencer/synthesizer/drum box's MIDI output 'Pulses are set to appx 10V (ARP compatible) in this code 'see code comments to adjust pulse amplitude to 5V ' ' ' MIDI INTERFACE Program Developed by Dave Brown ' Built with code pieces from Grant Richter & Brice Hornback ' Date: April 18, 2004 ' History: 0.1 Added DAC & led initialization, 1 mS timer ' functionality, stop led blinks when MIDI data ' received, run led blink at 0.5 seconds for ' health indicator ' 0.0 Initial release of MIDI input and output routines ' ' ' ' '***************************************************** ' ' Basic Micro Atom Pro-24M Configuration ' Note: P0 is I/O 0 and NOT pin 0 on the microprocessor ' P0 - Analog IN-1 (0-5 VDC) ' P1 - Analog IN-2 (0-5 VDC) ' P2 - Analog IN-3 (0-5 VDC) ' P3 - Analog IN-4 (0-5 VDC) ' P4 - START button (momentary normally open switch) ' P5 - STOP button (momentary normally open switch) ' P6 - I2C/SDA (reserved) - J3 Pin 1 ' P7 - I2C/SDL (reserved) - J3 Pin 2 ' P8 - AUX (Digital I/O - no buffering) ' P9 - STOP LED ' P10 - RUN LED (line 50) ' P11 - DAC - LOADDACS ' P12 - DAC - SERDATA ' P13 - DAC - CLOCK ' P14 - RXD (reserved) - J5 Pin 1 (MIDI) ' P15 - TXD (reserved) - J5 Pin 2 (MIDI) ' '***************************************************** ' ' ### CONDITIONAL COMPILING OPTION ### ' Set POLLED or INTERRUPT driven MIDI input ' 'Comment out next line for polled mode IM_FLAG CON 1 'Defined for interrupt mode 'Commented for polled mode ' '***************************************************** ' 'Defined Variables LOADDACS CON 11 'Pin OUT to DAC LOADDACS SERDATA CON 12 'Pin OUT Serial Data to DAC (16-bit) CLOCK CON 13 'Pin OUT to Clock DAC STOPLED CON 9 'Red LED RUNLED CON 10 'Green LED BSTART CON 5 'Start Button BSTOP CON 4 'Stop Button AUX CON 8 'AUX Jack (unbuffered) ' NOTEOFF CON $80 'MIDI note off command NOTEON CON $90 'MIDI note on command MIDICHAN VAR NIB MIDINOTE VAR BYTE MIDIVEL VAR BYTE ' MIDIDATA VAR BYTE 'MIDI data variable for subroutines I_DATA VAR BYTE 'MIDI data variable for interrupt routine STATUS VAR BYTE 'MIDI status data RPTR_S VAR BYTE 'Received data start pointer (first data in buffer) RPTR_E VAR BYTE 'Received data end pointer (last data in buffer+1) RBUFNUM VAR BYTE 'Number of bytes in received data buffer RDATAF VAR BYTE 'Received data flag 1=data, 0=no data RBUFL CON 32 'Receive buffer length RBUF VAR BYTE(RBUFL) 'Receive buffer data ' PPQ VAR BYTE 'counter for 24 pulses per quarter note TIMECOUNT VAR LONG '1 mS timer count TURNOFF VAR LONG 'Time to turn off stop led ' RAWDAC1 VAR WORD 'Raw DAC data 1 RAWDAC2 VAR WORD 'Raw DAC data 2 RAWDAC3 VAR WORD 'Raw DAC data 3 RAWDAC4 VAR WORD 'Raw DAC data 4 ' DAC1V VAR WORD 'DAC value to be sent to DAC channel DAC2V VAR WORD 'DAC value to be sent to DAC channel DAC3V VAR WORD 'DAC value to be sent to DAC channel DAC4V VAR WORD 'DAC value to be sent to DAC channel ' ADC1 CON 0 ADC2 CON 1 ADC3 CON 2 ADC4 CON 3 ' ADC1V VAR WORD 'Input A/D buffer channel 1 ADC2V VAR WORD 'Input A/D buffer channel 2 ADC3V VAR WORD 'Input A/D buffer channel 3 ADC4V VAR WORD 'Input A/D buffer channel 4 ' '***************************************************** ' 'Initialize PSIM DIRS = %0111110000000000 'Configure Pins: 1=output, 0=input OUTS = %0111111111111111 'Configure state: 1=high, 0=low ' 'Initialize serial hardware and ports 'These next 6 commands need to be in this order! LET SCR3=%00000000 'Reset Serial Control Register LET SMR=%00000000 'Set Serial Mode Register ' Asynchronous ' 8 bits ' Parity disabled ' Even parity (disabled) ' 1 stop bit ' Multiprocessor mode disabled ' BRR clock source direct LET BRR=15 'Set Bit Rate Register for 31500 baud PAUSEUS 100 'Let BRR settle for 50 uS LET SCR3=%00110000 'Set Serial Control Register ' Transmit or receive interrupts disabled ' Transmit and receive enabled ' Multiprocessor interrupt disabled ' Transmit end interrupt disabled ' Internal baud rate generator LET PMR1=%00001110 'Set Port Mode Register ' P17 general I/O port ' P16 general I/O port ' P15 general I/O port ' P14 general I/O port ' TXD output ' P10 general I/O port ' 'setup timerw for 1 millisecond interupts LET TMRW=%10001000 'Set Timer Mode Register to enable count LET TCRW=%10110000 'Set Timer Control Register ' TCNT cleared by compare match ' /8 internal clock LET TIERW=%01110000 'Set Timer Interrupt register to disable overflow interrupt LET TSRW=%01110000 'Set Timer Status Register to default LET TIOR0=%10001000 'Set Timer I/O Regiseter 0 to default LET TIOR1=%10001000 'Set Timer I/O Register 1 to default LET GRA=2000 'Set General Register A ' 16 MHz clock /8 = 2 MHz ' 2000 counts = 1 millisecond interrupt ' 'Initialize variables LET RPTR_S=0 'Initialize receive start pointer LET RPTR_E=0 'Initialize receive end pointer LET RBUFNUM=0 'Set receive buffer to empty LET MIDICHAN=0 'Set MIDI channel to 0 LET MIDIVEL=$40 'Set default velocity LET TIMECOUNT=0 'Set real time counter to 0 LET TURNOFF=0 'Set time to turn off to TIMECOUNT ' ONINTERRUPT TIMERWINT_IMIEA, CALCTIME #IFDEF IM_FLAG ONINTERRUPT SCI3INT_RDRF, MIDI_IN_ISR ENABLE SCI3INT_RDRF 'Enable receive interrupt #ENDIF ENABLE TIMERWINT_IMIEA 'Enable timer interrupt ' '***************************************************** 'Main program goes here 'Test with simple loop-through program 'Flash stop led when MIDI received LET DAC1V=0 'Set outputs to 0 LET DAC2V=0 LET DAC3V=0 LET DAC4V=0 GOSUB LOADALLDACS LOW STOPLED 'Initialize leds HIGH RUNLED PPQ=0 MAIN: #IFNDEF IM_FLAG GOSUB CHECK_MIDI 'Poll MIDI input if not interrupt driven #ENDIF IF RBUFNUM<>0 THEN 'Check to see if any MIDI data received GOSUB GET_RBUFFER 'Get data from received buffer HIGH STOPLED ' tell the people we got MIDI! IF MIDIDATA = 0xF8 THEN 'hex F8 is MIDI beat clock, SYSTEM REALTIME MESSAGE. 24 of these critters go by during every QUARTER NOTE IF PPQ = 96 THEN '96 = 24 x 4, PPQ is cleared every BAR of 4/4; 4 quater notes DAC4V = 4095 'send the leading edge of a pulse out of CVout 4; TO CHANGE ALL PULSES TO 5v, SET ALL DAC OUTPUTS TO 2048 INSTEAD OF 4095 GOSUB LOADALLDACS PPQ = 0 'then clear PPQ in order to start over on another bar ENDIF PPQ = PPQ + 1 'increment PPQ every time hex F8 goes by IF (PPQ // 3) = 0 THEN 'SETS PULSE WIDTH... to 3 occurences of hex F8 - thus pulses are one 32nd note wide IF DAC1V <> 0 THEN 'if a pulse is already on on any CV out then turn it off (trailing edge of pulse) DAC1V = 0 ENDIF IF DAC2V <> 0 THEN DAC2V = 0 ENDIF IF DAC3V <> 0 THEN DAC3V = 0 ENDIF IF DAC4V <> 0 THEN DAC4V = 0 ENDIF GOSUB LOADALLDACS ENDIF IF (PPQ // 6) = 0 THEN 'PPQ is divisible evenly by 6 (16th note)send the leading edge of a pulse out of CVout1 DAC1V = 4095 GOSUB LOADALLDACS ENDIF IF (PPQ // 12) = 0 THEN 'PPQ is divisible evenly by 12 (8th note)send the leading edge of a pulse out of CVout1 DAC2V = 4095 GOSUB LOADALLDACS ENDIF IF (PPQ // 24) = 0 THEN 'PPQ is divisible evenly by 24 (quarter note)send the leading edge of a pulse out of CVout1 DAC3V = 4095 GOSUB LOADALLDACS ENDIF ENDIF DISABLE TIMERWINT_IMIEA TURNOFF=TIMECOUNT+20 'Set time to turn off as current + 20 mS ENABLE TIMERWINT_IMIEA ENDIF GOTO MAIN 'End of simple loop through program '***************************************************** ' ' '***************************************************** '******************* SUBROUTINES ********************* '***************************************************** ' #IFNDEF IM_FLAG 'Poll subroutine for received MIDI 'Puts data into input buffer and sets RBUFNUM to number of entries CHECK_MIDI: LET STATUS=SSR IF STATUS & %01000000 THEN 'Data has been received LET MIDIDATA=RDR 'Read Receiver Data Register IF MIDIDATA<>$FE THEN 'Ignore if active status 'Put MIDIDATA into receive buffer 'Check to see if buffer full IF RBUFNUM=RBUFL THEN 'Buffer is full 'Simply loose data ELSE 'Buffer has space LET RBUF(RPTR_E)=MIDIDATA LET RBUFNUM=RBUFNUM+1 'Set RBUFNUM to number of entries LET RPTR_E=RPTR_E+1 'Increment pointer for next entry IF RPTR_E=RBUFL THEN RPTR_E=0 'Wrap pointer at max value ENDIF ENDIF ENDIF ELSE 'No data received 'Check if error IF STATUS & %00111000 THEN 'Error condition LET STATUS=STATUS & %10000111 LET SSR=STATUS 'Reset error bits ENDIF ENDIF RETURN #ENDIF ' 'Get MIDIDATA from receive buffer 'RDATAF=1 if successful, RDATAF=0 if no data in buffer GET_RBUFFER: #IFDEF IM_FLAG 'The interrupt service routine uses the same variables 'Need to ensure they do not change during this routine DISABLE SCI3INT_RDRF #ENDIF 'Check to see if buffer empty IF RBUFNUM=0 THEN 'Buffer is empty RDATAF=0 'Set empty flag ELSE 'Buffer has data LET MIDIDATA=RBUF(RPTR_S) LET RBUFNUM=RBUFNUM-1 LET RPTR_S=RPTR_S+1 IF RPTR_S=RBUFL THEN LET RPTR_S=0 'Wrap pointer at max value ENDIF LET RDATAF=1 'Set data returned flag ENDIF #IFDEF IM_FLAG ENABLE SCI3INT_RDRF #ENDIF RETURN ' 'Subroutine to send MIDIDATA 'Waits until transmitter ready SEND_MIDI: LET STATUS=SSR IF STATUS & %10000000 THEN 'Check transmitter ready 'Ready to transmit LET TDR=MIDIDATA 'Send data to TDR RETURN ELSE GOTO SEND_MIDI ENDIF ' 'Output 3 byte note on sequence NOTE_ON: LET MIDIDATA=NOTEON+MIDICHAN GOSUB SEND_MIDI LET MIDIDATA=MIDINOTE GOSUB SEND_MIDI LET MIDIDATA=MIDIVEL GOSUB SEND_MIDI RETURN ' 'Output 3 byte note off sequence NOTE_OFF: LET MIDIDATA=NOTEOFF+MIDICHAN GOSUB SEND_MIDI LET MIDIDATA=MIDINOTE GOSUB SEND_MIDI LET MIDIDATA=MIDIVEL GOSUB SEND_MIDI RETURN ' 'Add addresses to values (No speed improvement with OR over +) LOADALLDACS: LET RAWDAC1=DAC1V+49152 LET RAWDAC2=DAC2V+32768 LET RAWDAC3=DAC3V+16384 LET RAWDAC4=DAC4V 'Shift out 16 bits mode 4 gotta bang loaddacs pin for each channel 'Skew from channels 1 to 4 = 400 usecs 'Approximately 1 msec execution time for subroutine SHIFTOUT SERDATA,CLOCK,4,[RAWDAC1\16] PULSOUT LOADDACS,1 SHIFTOUT SERDATA,CLOCK,4,[RAWDAC2\16] PULSOUT LOADDACS,1 SHIFTOUT SERDATA,CLOCK,4,[RAWDAC3\16] PULSOUT LOADDACS,1 SHIFTOUT SERDATA,CLOCK,4,[RAWDAC4\16] PULSOUT LOADDACS,1 RETURN ' 'Load buffers with actual A/D values SCANADC: ADIN ADC1, ADC1V ADIN ADC2, ADC2V ADIN ADC3, ADC3V ADIN ADC4, ADC4V RETURN ' ' '***************************************************** '************ INTERRUPT SERVICE ROUTINES ************* '***************************************************** ' 'Interrupt service routine for timer CALCTIME: LET TIMECOUNT=TIMECOUNT+1 'Increment real time count IF TIMECOUNT=TURNOFF THEN 'Value to turn off stopled LOW STOPLED ENDIF IF (TIMECOUNT&$000001FF)=$00000100 THEN TOGGLE RUNLED 'Blink run led at 0.512 second intervals ENDIF RESUME ' ' #IFDEF IM_FLAG 'Interrupt service routine for received MIDI data 'Puts data into input buffer and sets RBUFNUM to number of entries MIDI_IN_ISR: 'Do not check SSR 'Does not function in interrupt mode LET I_DATA=RDR 'Read Receiver Data Register IF I_DATA<>$FE THEN 'Ignore if active status 'Check to see if buffer full IF RBUFNUM=RBUFL THEN 'Buffer is full 'Simply loose data ELSE 'Put data into buffer LET RBUF(RPTR_E)=I_DATA LET RBUFNUM=RBUFNUM+1 'Set RBUFNUM to number of entries LET RPTR_E=RPTR_E+1 'Increment pointer for next entry IF RPTR_E=RBUFL THEN RPTR_E=0 'Wrap pointer at max value ENDIF ENDIF ENDIF RESUME #ENDIF ' 'End of program