Switch and Controller MIDI Foot Pedals
This unit converts up to 8 variable potentiometer and up to 9 switch
foot-pedals to an associated MIDI control signal. This unit will work with one,
two or up to all 17 inputs, at the same time.
The Switch and Controller MIDI Foot Pedal utilizes:
- A Printed Circuit Board (PCB),
- A pre-programmed 16F877 PIC,
- 8 inputs for variable potentiometer foot pedals,
- 9 inputs for switch type foot-pedals,
- A power-on LED,
- A 4-way DIP switch which selects the MIDI channel at power-on, see Table
3
- a MIDI 5-pin DIN output socket, see Circuit
Schematic Diagram
The Switch and Controller MIDI Foot Pedal also requires:
Operation:
At power-on the DIP switch positions are read and the unit will operate in a
MIDI channel as shown in Table 3.
MIDI Pedal Switch Functions:
|
Switch Input Selections |
MIDI Pedal Functions |
| 1 |
Sustain |
| 2 |
Sostenuto |
| 3 |
Soft Pedal |
| 4 |
Legato |
| 5 |
Hold 2 |
| 6 |
Portamento |
| 7 |
Start |
| 8 |
Stop |
| 9 |
Continue |
|
Table 1 |
Sustain Pedal:
The sustain pedal is also known as the Damper Pedal. When operated it sends
out a controller value of CC64. When the pedal is pressed ON the unit outputs a
value of 127, when released OFF the unit outputs a value of 0. Tone-generators
without the 'half-damper' implemented will interpret a value between 0 and 63 as
OFF and a value of 64 to 127 as ON.
Sostenuto Pedal:
The sostenuto pedal is a type of selective sustain pedal found on acoustic
grand-pianos. Pressing down the pedal, sending controller value CC66 with a
value of 127, while holding notes on the keyboard will cause these notes to be
sustained after you release them. Any notes played after pressing the pedal will
not sustain. When the pedal is released it sends out controller value CC66 with
a value of 0.
Soft Pedal:
The soft pedal works in two simultaneous ways. When the pedal is pressed,
sending out controller value CC67 with a value of 127, the sound should be
slightly softened in terms of volume and there should be a noticeable difference
in the tone-colour of the sound. When the pedal is released it sends out
controller value CC67 with a value of 0.
Legato Pedal:
When the legato pedal is pressed, sending out controller value CC68 with a
value of 127, playing a different note changes the pitch of the current note
without re-triggering the attack phase of the envelope of the sound. When the
pedal is released it sends out controller value CC68 with a value of 0.
Hold 2 Pedal:
The hold 2 pedal is another type of sustaining pedal used fro sounds with two
sustain phases in their envelopes. When the pedal is pressed it sends out
controller value CC69 with a value of 127, when the pedal is released it sends
out controller value CC69 with a value of 0.
Portamento Pedal :
Portamento or glide is a synthesiser effect. It is mainly used for
synthesiser leads and sound effects. The effect is a regular sliding from one
note to another, in a similar way to pitch bend, but in this case it is the time
taken rather than the distance that has to be specified.
Portamento uses two separate controllers. Controller CC5 is used to set the
portamento Time, how long it takes to change the pitch by a semitone, which has
a range of 0-127. The portamento time value is associated with the
variable potentiometer value fed to controller input 8.
When the portamento pedal is pressed it sends out controller value CC65 with
a value of 127. When the pedal is released it sends out controller value CC65
with a value of 0.
The portamento effect does not require the playing to be legato, the pitch
will always slide from the last note played, however long you pause between the
two.
If chords are played with the portamento effect then the sliding becomes
haphazard as any note from the first chord could slide to any note of the
second.
Start Pedal:
When the Start pedal is operated it sends a MIDI start code when the
foot-switch is pressed. This can be used to control the start/stop
time of a MIDI hardware/software sequencer, allowing a musician hands free
operation.
Stop Pedal:
When the Stop pedal is operated it sends a MIDI stop code
when the foot-switch is pressed. This can be used to control the
start/continue/stop time of a MIDI hardware/software sequencer, allowing a
musician hands free operation.
Continue Pedal:
When the Continue pedal is operated it sends a MIDI continue code
when the foot-switch is pressed. This will continue a MIDI sequence from
where it was stopped with the stop pedal. This can be used to control the
start/continue/stop time of a MIDI hardware/software sequencer, allowing a
musician hands free operation.
MIDI Pedal Controller Functions:
|
Controller Input Selections |
MIDI Pedal Functions |
| 1 |
Volume |
| 2 |
Modulation |
| 3 |
Breath Control |
| 4 |
Pitch |
| 5 |
Balance |
| 6 |
Pan |
| 7 |
Expression |
| 8 |
Portamento Time |
|
Table 2 |
|
DIP Switch Selections |
MIDI Channels |
| 4 |
3 |
2 |
1 |
| on |
on |
on |
on |
1 |
| on |
on |
on |
off |
2 |
| on |
on |
off |
on |
3 |
| on |
on |
off |
off |
4 |
| on |
off |
on |
on |
5 |
| on |
off |
on |
off |
6 |
| on |
off |
off |
on |
7 |
| on |
off |
off |
off |
8 |
| off |
on |
on |
on |
9 |
| off |
on |
on |
off |
10 |
| off |
on |
off |
on |
11 |
| off |
on |
off |
off |
12 |
| off |
off |
on |
on |
13 |
| off |
off |
on |
off |
14 |
| off |
off |
off |
on |
15 |
| off |
off |
off |
off |
16 |
|
Table 3 MIDI Channels |
TOM SCARFF
1 Martello Court
Portmarnock
Dublin
Ireland.
Email: tscarff@eircom.net
|
