Arduino MIDI controller: using more than 4 inputs

Forum 2005-2010 (read only) Software Interfacing
1

Hey guys,

I'm working on a MIDI controller that uses the 6 analog inputs and 2 or 4 digital ones on the duemillanove. I got my basic setup working but now I find that it won't read more than 4 inputs.
Is that maybe a restriction on the arduino board? Or is it down to not having enough power (I use the power from the USB)? Or the script?

// Arduino MULTI MIDI CC script

//ARRAYS FOR ANALOG
int inputsAnalog[] = {0, 1, 2, 3, 4, 5};
int channelsAnalog[] = {1, 2, 3, 4, 5, 6};
int lastAnalogs[]= {0, 0, 0, 0, 0, 0};

//ARRAYS FOR DIGITAL
int inputsDigital[] = {4, 7, 8, 12, 13};
int channelsDigital[] = {1, 2, 4, 5, 6, 7};
int lastDigital[]= {LOW, LOW, LOW, LOW, LOW, LOW};

//ANALOG SMOOTHING
int analogSmooth = 2;
long time = 0;
long debounce = 200;
int previous = LOW;

void setup()
{
Serial.begin(9600);
}

void loop()
{
for (int i=0; i<2; i++)
{
doReadAnalog(i, inputsAnalog, channelsAnalog_, lastAnalogs*);
 } *_

* for (int i=0; i<2; i++)*
* {*
doReadDigital(i, inputsDigital_, channelsDigital*);
}
}
void doReadAnalog(int i, int input, int channel, int lastAnalog)
{
int readingAnalog = 0;
readingAnalog = analogRead(input)/8;
if (abs(readingAnalog-lastAnalog) > analogSmooth)
{
lastAnalogs = readingAnalog;
controlChange(channel, 10, readingAnalog); // Send CC10*
* }
}
void doReadDigital(int i, int input, int channel)
{
int readingDigital = 0;
readingDigital = digitalRead(input);*_

_ if(lastDigital != readingDigital)
* {
if(readingDigital == HIGH && previous == LOW && millis() - time > debounce)
{
controlChange(channel, 11, 0);
}else{
controlChange(channel, 11, 127);
}
lastDigital = readingDigital;
}
}
// Send a MIDI control change*
void controlChange(byte channel, byte controller, byte value)
{
* midiMsg(channel+0xB0, controller, value);
}
// Send a general MIDI message*
void midiMsg(byte cmd, byte data1, byte data2)
{
* Serial.print(cmd, BYTE);
Serial.print(data1, BYTE);
Serial.print(data2, BYTE);
}*_

2

Do you mean four digital inputs or 4 (out of the six) analog inputs? If you have run out of pins, you can use some of the well-known multiplexing techniques to expand the number of inputs.

3

no I'm not running out of pins, it's when I connect more than 2 pins, either digital or analog, it doesn't read them somehow.

4

Did you ever figure this out?
It sounds like it would be easy to reproduce. I'm embarking on an arduino midi controller project and looking for the gotchas.

thanks, matt