Basic Stamp Midi
Basic Stamp II MIDI input/output
This program demonstrates how to get MIDI output using a Basic Stamp IIsx.
The circuit connected to the Basic Stamp is shown below. The +5v power source for the circuit below comes from the DIP pin #21. The program uses I/O pin #8 (DIP pin #13) for the MIDI output, but you can change the program to use any output pin for MIDI out. The buffer op-amp does not seem to be necessary.
The primary function used in this program is the serout function. The first parameter to serout is the output pin (0-15,16). The second parameter is the baude mode which is set to the value 2,500,000/31,250 - 20 = 60. Where 31,250 is the data bit rate of the MIDI serial protocol.
'{$STAMP BS2SX}
''
'' Programmer: Craig Stuart Sapp
'' Creation Date: Sun 07-11-1999
'' Last Modified: Tue 07-13-1999
'' Filename: cout.bsx
'' Syntax: Basic Stamp IIsx
''
'' Description: This program sends out the MIDI note middle C
'' once every second. The note remains on for
'' 1/2 of a second, and then is turned off for
'' 1/2 of a second.
'' The MIDI note-on message is [$90, 60, 127], where
'' $90 = 144 = MIDI note-on command
'' 60 = Middle C as a MIDI note number
'' 127 = attack velocity (very loud)
'' The MIDI note-off message is [$90, 60, 0], where
'' $90 = a MIDI note-on command unless velocity is 0
'' 60 = the MIDI key to turn off
'' 0 = attack velocity of zero (i.e., turn note off)
''
'' The MIDI Output Circuit connected between 5v power and pin 8 is:
'' +5V to 220 Ohm to MIDI 2; MIDI 4 to 220 Ohm to a pin.
''
outpin con 8 ' output pin on which to send MIDI data
baudmode con 60 ' baude mode for serout: (2500000/31250)-20 msec
' note that this value should be 12 for BS2.
' Serial rate for MIDI is 31,250 data bits/sec.
outpause con 0 ' pause time in units of 0.4 millisec between bytes
' on the BS2, units are 1.0 millisec
' According to BASIC Stamp Programming Manual v1.9, page 208:
' "Unused pins that are not connected to circuitry should be set to output"
' to minimize power consumption.
' which is done here:
DIRS = %1111111111111111
' Don't set pins connected to input circuitry to be output, or you can
' damage the Basic Stamp.
top:
serout outpin, baudmode, outpause, [$90, 60, 127]
pause 493
serout outpin, baudmode, outpause, [$90, 60, 0]
pause 492
goto top:
' Note that the pause times of 493 and 492 are the values
' needed (found empirically) to get a total period of
' 1000 milliseconds for the loop. A three-byte MIDI message
' takes about 1 millisecond to send.
(http://devices.sapp.org/micro/stamp2sx/cout/cout.bsx)
----
result var word
tabval var word
tabval2 var word
input 1
noteon var word
rcheck
high 0
pause 1
RCTIME 0,1,result
if result < 223 and result > 0 then send
goto rcheck
send: lookdown result,<=[1,2,8,15,20,25,33,37,45,49,54,62,67,73,78,85,93,98,103,
110,117,122,129,135,140,145,152,158,164,170,175,182,188,194,200,205,213,220,225],tabval
serout 7, $8000+12, [144,tabval+20,127] 'the resistor value won't be the same
gosub send2 ' every time, so you gotta
serout 7, $8000+12, [128,tabval+20,127] ' pick the highest value that it shows up
return ' as through trial n error to make your table
send2: high 0
pause 1
RCTIME 0,1,noteon
if noteon > 225 then send3
lookdown noteon,<=[1,2,8,15,20,25,33,37,45,49,54,62,67,73,78,85,93
,98,103,110,117,122,129,135,140,145,152,158,164,170,175,182,188,194,200,205,213,220,225],tabval2
if tabval2=tabval then send
return
send3:
noteon = result ' this takes care of an unacceptable value from the POT
return ' measurement...
' this code could be much more elegant, but it works... lemme know if you do something
' cool w/it.
' thanks to Jon Radenberg's basic stamp2 "knob box" for the inspiration for this project
' http://www.geopath.com/~jraden/knobs.html
----
' MIDI CODE TX
' Programs to emit MIDI CODE from a BSII starting from the
' reading of three pots and four buttons
' DESCRIPTION:
' It is a console to send out MIDI code with four
' buttons for the emission of note_on code and three pots
' for the emission of control-change code (Main Volume - Bread and
' Expression) .A selection button
' allows, by means of successive pulsations to select among those
' analogical entrances with the pots and the digital inputs from the buttons in
' in two banks of four buttons.The midi code emission is always made in the one
' channel 0 and the notes correspond the C3 (36) from now on.
' The selection recycles among 5 steps: 1) four low buttons, 2) four high buttons.
' 3) pot 1, 4) Joystick with two pots, 5) 3th Pot and joystick
' Roberto Gomez [robby@abaconet.com.ar]
'
'
'HARDWARE:
'P0 Joystick vertical pot
'P1 Joystick Horizontal pot
'P2 3th Pot
'
'P4 Joystick Led
'P5 3th pot led
'P6 First four buttons led
'P7 Seconds four buttons led
'P8 Input button 1
'P9 Input button 2
'P10 Input button 3
'P11 Input button 4
'P12 Selection button
'P13 MIDI Output
'P14 LCD Clock Only for debug
'P15 LCD Data
'VARIABLES:
Display data 0,1,2,4,8,12
Pot1 con 0
Pot2 con 1
Pot3 con 2
LedPot1 con 4
LedJoy con 5
LedBan1 con 6
LedBan2 con 7
Pul1 con 8
Pul2 con 9
Pul3 con 10
Pul4 con 11
Selec con 12
Midiout con 13
ClkLcd con 14
DataLcd con 15
Nota var byte
Not1 var byte
Not2 var byte
Seleccion var nib 'Selector position
x var nib
y var word
VarBut var byte 'Button command var
TipoMens var byte 'Mensage type
Dato var byte
cuenta var word
ValPot var byte(3)
Control var nib
Leds var nib
Sel var bit
z var nib
c var byte
boton var nib
'INICIALITATION:
DIRS=%1110000011110000
'The start is in the first four buttons bank
Seleccion=0
VarBut=0
Dato=$24 'First note
serout Midiout,12,[$FA] 'Send Start (FAH)
Main:
loop:
Button Selec,0,255,0,VarBut,1,accion
Seleccion = Seleccion + 1
if Seleccion > 5 then otra
read display+seleccion,c
OutB = c 'Correspondig led on
pause 1000
goto loop
otra: Seleccion = 0:goto loop
Accion: Pause 2000
Seleccion = Seleccion - 1 'First Selection = 0
Loopot: Branch Seleccion,[Accion1,Accion2,Pote1,Joy,JoyPot]
Accion1:
x=8
Loop1: Button x,0,255,0,VarBut,1,boton1
x=x+1
if x>12 then accion1
goto loop1
boton1:
x=x-8
Branchon: Branch x,[Notaon1,Notaon2,Notaon3,Notaon4,main]
goto main
Branchoff1: Branch x,[Notaoff1,Notaoff2,Notaoff3,Notaoff4,main]
goto main
Notaon1:
Nota = $24
gosub EnvPulon
goto Levanta1
Notaoff1:
Nota =$24
gosub EnvPulOff
goto accion1
Notaon2:
Nota = $25
gosub EnvPulon
goto Levanta1
Notaoff2:
Nota =$25
gosub EnvPulOff
goto accion1
Notaon3:
Nota = $26
gosub EnvPulon
goto Levanta1
Notaoff3:
Nota =$26
gosub EnvPulOff
goto accion1
Notaon4:
Nota = $27
gosub EnvPulon
goto Levanta1
Notaoff4:
Nota =$27
gosub EnvPulOff
goto accion1
Accion2:
x=8
loop2: Button x,0,255,0,VarBut,1,boton2
x=x+1
if x>12 then accion2
goto loop2
Boton2:
x=x-8
Branch x,[Notaon5,Notaon6,Notaon7,Notaon8,main]
goto main
Branchoff2: Branch x,[Notaoff5,Notaoff6,Notaoff7,Notaoff8,main]
goto main
Notaon5:
Nota = $28
gosub EnvPulon
goto Levanta2
Notaoff5:
Nota =$28
gosub EnvPulOff
goto accion2
Notaon6:
Nota = $29
gosub EnvPulon
goto Levanta2
Notaoff6:
Nota =$29
gosub EnvPulOff
goto accion2
Notaon7:
Nota = $2A
gosub EnvPulon
goto Levanta2
Notaoff7:
Nota =$2A
gosub EnvPulOff
goto accion2
Notaon8:
Nota = $2B
gosub EnvPulon
goto Levanta2
Notaoff8:
Nota =$2B
gosub EnvPulOff
goto accion2
Pote1:
'3th Pot
TipoMens = $B0
Control = 7 'Main Volumen
x=2
High Pot3
Pause 1
RCtime Pot3,1,cuenta
If cuenta > 300 then bien
cuenta = 300
Bien: ValPot(x) = cuenta - 300
If NOT ValPot(x)>127 then Sigue1
ValPot(x)=127
sigue1: gosub EnvPot
goto Reci
Joy:
'Joystick Pot
TipoMens = $B1 'Canal 2
Control = 10 'Pan Controller
x=0
High Pot1
Pause 1
RCtime Pot1,1,cuenta
If cuenta > 300 then bien1
cuenta = 300
bien1: ValPot(x) = cuenta - 300
If NOT ValPot(x)>127 then Sigue2
ValPot(x)=127
sigue2: gosub EnvPot
TipoMens = $B2 'Canal 3
Control = 11 'Expression Controller
x=1
High Pot2
Pause 1
RCtime Pot2,1,cuenta
If cuenta > 300 then bien2
cuenta = 300
bien2: ValPot(x)=cuenta - 300
If NOT ValPot(x)>127 then Sigue3
ValPot(x)=127
sigue3: gosub EnvPot
goto Reci
JoyPot:
TipoMens = $B1
Control = 10
x=0
High Pot1
Pause 1
RCtime Pot1,1,cuenta
If cuenta > 300 then bien3
cuenta = 300
bien3: ValPot(x) = cuenta - 300
If NOT ValPot(x)>127 then Sigue4
ValPot(x)=127
Sigue4: gosub EnvPot
TipoMens = $B2
Control = 11
x=1
High Pot2
Pause 1
RCtime Pot2,1,cuenta
If cuenta > 300 then bien4
cuenta = 300
bien4: ValPot(x) = cuenta - 300
If NOT ValPot(x)>127 then Sigue5
ValPot(x)=127
Sigue5: gosub EnvPot
TipoMens = $B0
Control = 7
x=2
High Pot3
Pause 1
RCtime Pot3,1,cuenta
If cuenta > 300 then bien5
cuenta = 300
bien5: ValPot(x) = cuenta - 300
If NOT ValPot(x)>127 then Sigue6
ValPot(x)=127
Sigue6: gosub EnvPot
Reci:
C=IN12
If C=0 then main
goto loopot
EnvPulon:
serout Midiout,12,[$93,Nota,64]
'Debug "NOTAON:",hex Nota,13
Return
EnvPuloff:
serout Midiout,12,[$83,Nota,64]
'Debug "NOTAOFF:",hex Nota,13
Return
EnvPot:
serout Midiout,12,[TipoMens,Control,ValPot(x)]
'Debug hex ?TipoMens ,? ValPot(x),13
Return
Levanta1:
z=x+8
NoLev1: Button z,1,255,0,VarBut,0,NoLev1
Branch x,[Notaoff1,Notaoff2,Notaoff3,Notaoff4,main]
Levanta2:
z=x+8
NoLev2: Button z,1,255,0,VarBut,0,NoLev2
Branch x,[Notaoff5,Notaoff6,Notaoff7,Notaoff8,main]
end
----
it was a laser-based interactive midi instrument I built for the burning man arts festival.
I have a number of boards put together that do multiple switches into the midi output.
(http://www.zenchemical.com/burningman/congruence)
----
MIDI output
Very easy to wire up. Use the Stamp II "serout" command, with baud rate number of 12 (which corresponds to the MIDI rate of 31250 baud). You need to know something about the format of MIDI commands (look here and here). You'll be sending three or four bytes down the line in this sort of format:
SEROUT 15,12,0,[144,60,80]
The numbers in the square brackets are a MIDI note-on message
144 = "This is a note-on, on MIDI channel 1"
60 = "Middle C"
80 = "Medium loud"
MIDI input
Well, I did once establish that it is possible, but it is extremely unreliable. Wiring it up is a little more complicated too, as it involves an optoisolator chip and a few other components. The problem is that the Stamp, having no interrupt, will miss bytes unless you are there at the right moment to catch them with the SERIN command. Then you will have to write a MIDI parser to determine what the received bytes mean.
(http://mrogalsky.web.wesleyan.edu/otherthings/voltage-midi/stampMIDI.html)
----
' BASIC Stamp II "MIDI LightHarp"
' with 6 photocells, Nat. Semi. 1 of 8 multiplexer CD4051BCN, and
' Nat. Semi. ADC0831
' based on Parallax A/D application notes
' Matt Rogalsky April 1996
CS con 0 ' chip select is pin 0
ADCdata con 1 ' ADC data out is pin 1
CLK con 2 ' ADC clock is pin 2
MUXa con 3 ' MUX channel select lines
MUXb con 4
MUXc con 5
threshold var byte ' threshold below which a photocell
threshold = 100 ' will send a MIDI note-on message
AD0 var byte ' to hold data shifted in from ADC
AD1 var byte ' for each of 6 photocells
AD2 var byte
AD3 var byte
AD4 var byte
AD5 var byte
flag0 var byte ' flags to indicate if photocell was triggered
flag1 var byte
flag2 var byte
flag3 var byte
flag4 var byte
flag5 var byte
key0 var byte ' MIDI note numbers assigned to photocells
key1 var byte
key2 var byte
key3 var byte
key4 var byte
key5 var byte
key0 = 60 ' 60 = middle C
key1 = 62 ' 62 = D
key2 = 64 ' 64 = E
key3 = 65 ' 65 = F
key4 = 67 ' 67 = G
key5 = 69 ' 69 = A
high CS ' deselect ADC to start
loop: ' MAIN LOOP
do0:
gosub select0
gosub sample0
do1:
gosub select1
gosub sample1
do2:
gosub select2
gosub sample2
do3:
gosub select3
gosub sample3
do4:
gosub select4
gosub sample4
do5:
gosub select5
gosub sample5
goto loop
' **** send MIDI note-ons on MIDI channel 1, using Stamp pin 15 ********
' note-on velocity is a constant of 80
note0:
serout 15,12,0,[144,key0,80]
flag0 = 0
goto do1
note1:
serout 15,12,0,[144,key1,80]
flag1 = 0
goto do2
note2:
serout 15,12,0,[144,key2,80]
flag2 = 0
goto do3
note3:
serout 15,12,0,[144,key3,80]
flag3 = 0
goto do4
note4:
serout 15,12,0,[144,key4,80]
flag4 = 0
goto do5
note5:
serout 15,12,0,[144,key5,80]
flag5 = 0
goto do0
' ******* sample photocells 0-5, after selecting MUX channel *****
sample0:
low CS ' activate ADC
shiftin ADCdata,CLK,msbpost,[AD0\9] ' shift in data
high CS ' deactivate ADC
if AD0 < threshold and flag0 = 1 then note0
if AD0 > threshold then flag0high
return
sample1:
low CS
shiftin ADCdata,CLK,msbpost,[AD1\9]
high CS
if AD1 < threshold and flag1 = 1 then note1
if AD1 > threshold then flag1high
return
sample2:
low CS
shiftin ADCdata,CLK,msbpost,[AD2\9]
high CS
if AD2 < threshold and flag2 = 1 then note2
if AD2 > threshold then flag2high
return
sample3:
low CS
shiftin ADCdata,CLK,msbpost,[AD3\9]
high CS
if AD3 < threshold and flag3 = 1 then note3
if AD3 > threshold then flag3high
return
sample4:
low CS
shiftin ADCdata,CLK,msbpost,[AD4\9]
high CS
if AD4 < threshold and flag4 = 1 then note4
if AD4 > threshold then flag4high
return
sample5:
low CS
shiftin ADCdata,CLK,msbpost,[AD5\9]
high CS
if AD5 < threshold and flag5 = 1 then note5
if AD5 > threshold then flag5high
return
' ************* select channels 0-5 of MUX *************
select0:
low MUXa
low MUXb
low MUXc
return
select1:
high MUXa
low MUXb
low MUXc
return
select2:
low MUXa
high MUXb
low MUXc
return
select3:
high MUXa
high MUXb
low MUXc
return
select4:
low MUXa
low MUXb
high MUXc
return
select5:
high MUXa
low MUXb
high MUXc
return
' ****************** set flags high ******************
flag0high:
flag0 = 1
goto do1
flag1high:
flag1 = 1
goto do2
flag2high:
flag2 = 1
goto do3
flag3high:
flag3 = 1
goto do4
flag4high:
flag4 = 1
goto do5
flag5high:
flag5 = 1
goto do0
----
' "green lunchbox" general purpose voltage to midi controller
' based on Parallax A/D application notes
' Matt Rogalsky December 1997
' select 1 of 16 multiplexer (MC14067)
' and read data from ADC0831
' pins 0,1,2 are used to control the ADC chip
' pins 3,4,5,6 are used to select the MUX channel
' results are sent out (reduced to 7 bits from 8) as
' controllers 20-35 on midi channel 1
' latest value is only sent if it is different from the
' previous one
CS con 0 ' chip select is pin 0
ADCdata con 1 ' ADC data out is pin 1
CLK con 2 ' ADC clock is pin 2
AD0 var byte ' to hold data shifted in from ADC
AD1 var byte ' for each of 16 channels
AD2 var byte
AD3 var byte
AD4 var byte
AD5 var byte
AD6 var byte
AD7 var byte
AD8 var byte
AD9 var byte
AD10 var byte
AD11 var byte
AD12 var byte
AD13 var byte
AD14 var byte
AD15 var byte
pAD0 var byte ' to hold previous data shifted in from ADC
pAD1 var byte ' for each of 16 channels
pAD2 var byte
pAD3 var byte
pAD4 var byte
pAD5 var byte
pAD6 var byte
pAD7 var byte
pAD8 var byte
pAD9 var byte
pAD10 var byte
pAD11 var byte
pAD12 var byte
pAD13 var byte
pAD14 var byte
pAD15 var byte
high CS ' deselect ADC to start
loop: ' MAIN LOOP
do0:
gosub select0
gosub sample0
do1:
gosub select1
gosub sample1
do2:
gosub select2
gosub sample2
do3:
gosub select3
gosub sample3
do4:
gosub select4
gosub sample4
do5:
gosub select5
gosub sample5
do6:
gosub select6
gosub sample6
do7:
gosub select7
gosub sample7
do8:
gosub select8
gosub sample8
do9:
gosub select9
gosub sample9
do10:
gosub select10
gosub sample10
do11:
gosub select11
gosub sample11
do12:
gosub select12
gosub sample12
do13:
gosub select13
gosub sample13
do14:
gosub select14
gosub sample14
do15:
gosub select15
gosub sample15
goto loop
' *** send MIDI CC 20 on MIDI channels 1-16, using Stamp pin 15 ***
cc0:
serout 15,12,0,[176,20,AD0]
pAD0 = AD0
goto do1
cc1:
serout 15,12,0,[176,21,AD1]
pAD1 = AD1
goto do2
cc2:
serout 15,12,0,[176,22,AD2]
pAD2 = AD2
goto do3
cc3:
serout 15,12,0,[176,23,AD3]
pAD3 = AD3
goto do4
cc4:
serout 15,12,0,[176,24,AD4]
pAD4 = AD4
goto do5
cc5:
serout 15,12,0,[176,25,AD5]
pAD5 = AD5
goto do6
cc6:
serout 15,12,0,[176,26,AD6]
pAD6 = AD6
goto do7
cc7:
serout 15,12,0,[176,27,AD7]
pAD7 = AD7
goto do8
cc8:
serout 15,12,0,[176,28,AD8]
pAD8 = AD8
goto do9
cc9:
serout 15,12,0,[176,29,AD9]
pAD9 = AD9
goto do10
cc10:
serout 15,12,0,[176,30,AD10]
pAD10 = AD10
goto do11
cc11:
serout 15,12,0,[176,31,AD11]
pAD11 = AD11
goto do12
cc12:
serout 15,12,0,[176,32,AD12]
pAD12 = AD12
goto do13
cc13:
serout 15,12,0,[176,33,AD13]
pAD13 = AD13
goto do14
cc14:
serout 15,12,0,[176,34,AD14]
pAD14 = AD14
goto do15
cc15:
serout 15,12,0,[176,35,AD15]
pAD15 = AD15
goto do0
' ****** sample photocells 0-15, after selecting MUX channel *****
sample0:
low CS ' activate ADC
shiftin ADCdata,CLK,msbpost,[AD0\9] ' shift in data
high CS ' deactivate ADC
AD0 = AD0 >> 1 ' divide by 2
if AD0 <> pAD0 then cc0 ' if new value, send as cc
return
sample1:
low CS
shiftin ADCdata,CLK,msbpost,[AD1\9]
high CS
AD1 = AD1 >> 1
if AD1 <> pAD1 then cc1
return
sample2:
low CS
shiftin ADCdata,CLK,msbpost,[AD2\9]
high CS
AD2 = AD2 >> 1
if AD2 <> pAD2 then cc2
return
sample3:
low CS
shiftin ADCdata,CLK,msbpost,[AD3\9]
high CS
AD3 = AD3 >> 1
if AD3 <> pAD3 then cc3
return
sample4:
low CS
shiftin ADCdata,CLK,msbpost,[AD4\9]
high CS
AD4 = AD4 >> 1
if AD4 <> pAD4 then cc4
return
sample5:
low CS
shiftin ADCdata,CLK,msbpost,[AD5\9]
high CS
AD5 = AD5 >> 1
if AD5 <> pAD5 then cc5
return
sample6:
low CS
shiftin ADCdata,CLK,msbpost,[AD6\9]
high CS
AD6 = AD6 >> 1
if AD6 <> pAD6 then cc6
return
sample7:
low CS
shiftin ADCdata,CLK,msbpost,[AD7\9]
high CS
AD7 = AD7 >> 1
if AD7 <> pAD7 then cc7
return
sample8:
low CS
shiftin ADCdata,CLK,msbpost,[AD8\9]
high CS
AD8 = AD8 >> 1
if AD8 <> pAD8 then cc8
return
sample9:
low CS
shiftin ADCdata,CLK,msbpost,[AD9\9]
high CS
AD9 = AD9 >> 1
if AD9 <> pAD9 then cc9
return
sample10:
low CS
shiftin ADCdata,CLK,msbpost,[AD10\9]
high CS
AD10 = AD10 >> 1
if AD10 <> pAD10 then cc10
return
sample11:
low CS
shiftin ADCdata,CLK,msbpost,[AD11\9]
high CS
AD11 = AD11 >> 1
if AD11 <> pAD11 then cc11
return
sample12:
low CS
shiftin ADCdata,CLK,msbpost,[AD12\9]
high CS
AD12 = AD12 >> 1
if AD12 <> pAD12 then cc12
return
sample13:
low CS
shiftin ADCdata,CLK,msbpost,[AD13\9]
high CS
AD13 = AD13 >> 1
if AD13 <> pAD13 then cc13
return
sample14:
low CS
shiftin ADCdata,CLK,msbpost,[AD14\9]
high CS
AD14 = AD14 >> 1
if AD14 <> pAD14 then cc14
return
sample15:
low CS
shiftin ADCdata,CLK,msbpost,[AD15\9]
high CS
AD15 = AD15 >> 1
if AD15 <> pAD15 then cc15
return
' ********** select channels 0-15 of MUX ***********
select0:
low 3
low 4
low 5
low 6
return
select1:
high 3
low 4
low 5
low 6
return
select2:
low 3
high 4
low 5
low 6
return
select3:
high 3
high 4
low 5
low 6
return
select4:
low 3
low 4
high 5
low 6
return
select5:
high 3
low 4
high 5
low 6
return
select6:
low 3
high 4
high 5
low 6
return
select7:
high 3
high 4
high 5
low 6
return
select8:
low 3
low 4
low 5
high 6
return
select9:
high 3
low 4
low 5
high 6
return
select10:
low 3
high 4
low 5
high 6
return
select11:
high 3
high 4
low 5
high 6
return
select12:
low 3
low 4
high 5
high 6
return
select13:
high 3
low 4
high 5
high 6
return
select14:
low 3
high 4
high 5
high 6
return
select15:
high 3
high 4
high 5
high 6
return