Programmable MIDI Controller Foot-Switch

The programmable MIDI controller foot-switch utilizes:

•  a stereo jack-socket, which also acts as the on/off switch, and associated 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 Diagram
•  a programme switch, a 4-way DIP switch (shown in Table 1) which selects the MIDI programme at power-on, and associated LED,

The programmable MIDI controller foot-switch requires:

• a 1/4 inch (6.35mm) Mono Foot Pedal
• a 9v battery or equivalent power source

Programming the unit:

At power-on, if the programme switch is simultaneously held on, then the unit will enter programme mode. The DIP switch positions are read and the unit will operate as shown in Table 1.

The switch position is stored internally in the EEPROM and will continue to operate in this mode, even if power is removed, until reprogrammed.

Normal Mode:

At power-on the DIP switch positions are read and the unit will operate in a MIDI channel as shown in Table 3. Also the EEPROM is read and the unit operates in the previously programmed pedal mode.

Note that at power-on, if the programme switch is ignored then the unit operates as previously programmed.

MIDI Pedal Functions:

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.

Start Pedal:

The start pedal sends a MIDI start code when the foot-switch is pressed. This can be used to control the start time of a MIDI hardware/software sequencer, allowing a musician hands free operation.

Start/Stop Pedal:

When Start/Stop  pedal is operated it sends a MIDI start code when the foot-switch is pressed for the first time and then a MIDI stop code when pressed a second time. Then the Start, Stop sequence is repeated with each alternate pressing of the foot-pedal switch. This can be used to control the start/stop time of a MIDI hardware/software sequencer, allowing a musician hands free operation.

Start/Continue/Stop Pedal:

When Start/Continue/Stop  pedal is operated it sends a MIDI start code when the foot-switch is pressed for the first time and then a MIDI continue code when pressed a second time and then a MIDI stop code when pressed for the third time. Then the Start, Continue,Stop sequence is repeated with each alternate pressing of the foot-pedal switch. This can be used to control the start/continue/stop time of a MIDI hardware/software sequencer, allowing a musician hands free operation.

Portamento Pedal (Time 0-7):

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. Table 2 shows the portamento time values associated with portamento time values of 0-7.

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 portameno effect then the sliding becomes haphazard as any note from the first chord could slide to any note of the second.

TOM SCARFF
1 Martello Court
Portmarnock
Dublin
Ireland.

Email: tscarff@eircom.net