# Fix code error **URL:** \ **Category:** Programming\ **Created:** [May 3, 2012, 9:23pm UTC](https://forum.arduino.cc/t/fix-code-error/101942 "2012-05-03T21:23:35Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 3, 2012, 9:23pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/1 "2012-05-03T21:23:35Z")
Hello, I have a code found on the net, wich i wanted to use as a basic to create my own code for my purpose. But i can't get the buggs out. Here is my code. Can please someone tellme what i'm doing wrong? ```cpp int ledPin = 13; int Basedrum  = 0; int Snare = 1; int Tom1 = 2; int Tom2 = 3; int Tom3 = 4; int Hihat = 5; int Crash = 6; int Ride = 7; byte val = 0; byte val2 = 0; byte val3 = 0; byte val4 = 0; byte val5 = 0; byte val6 = 0; byte val7 = 0; byte val8 = 0; int statePin = LOW; int THRESHOLD = 20; void setup() { pinMode(ledPin, OUTPUT); Serial.begin(115200); }   void loop() {   val = analogRead (Basedrum);      val2 = analogRead(Snare);   val3 = analogRead(Tom1);   val4 = analogRead(Tom2);   val5 = analogRead(Tom3);   val6 = analogRead(Hihat);   val7 = analogRead(Crash);   val8 = analogRead(Ride);         if (val > THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 36, val);     midi_note_off(0, 36, val);     delay(100);   }     if (val2 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 38, val2);   midi_note_off(0, 38, val2);   delay(100);   }     if (val3 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 40, val3);   midi_note_off(0, 40, val3);   delay(100); }       if (val4 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 43, val4);   midi_note_off(0, 43, val4);   delay(100); }     if (val5 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 45, val5);   midi_note_off(0, 45, val5);   delay(100); } if (val6 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 47, val6);   midi_note_off(0, 47, val6);   delay(100); } if (val7 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 49, val7);   midi_note_off(0, 49, val7);   delay(100); } if (val8 >= THRESHOLD) {     statePin = !statePin;     digitalWrite(ledPin, statePin);     midi_note_on(0, 51, val8);   midi_note_off(0, 51, val8);   delay(100); }   } ``` Thanks a lot!!! ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 3, 2012, 9:26pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/2 "2012-05-03T21:26:14Z")
(deleted) ---
**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\ **Post date:** [May 3, 2012, 9:27pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/3 "2012-05-03T21:27:47Z")
It stops at this line:- ```arduino    midi_note_on(0, 36, val); ``` and says > sketch\_may03a:47: error: 'midi\_note\_on' was not declared in this scope That means it has no idea what that function midi\_note\_on is, it is not defined anywhere in the sketch. Are you missing some sort of library? Or missing the definition of this function. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 7, 2012, 9:12pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/4 "2012-05-07T21:12:29Z")
Thanks a lot for your help! How do i " define" midi\_note\_on and Midi\_note\_off ? I try to understand the language and read examples from other programmers, but i can't find a rule that explains me to define that. Short version of what i want to create actually: === two shoes, each a FSR sensor sending to arduino uno with XBees. === On the arduino uno a display with two buttons to controll ( increase or degrease drumpreset like Accoustic and house/techno for example )or a touchscreen with those functions. === A Xbees receiver by my drummudule. Ik know what i want, but i don't have the Knowledge to programming :~ I think it's posible, but i need some help to get it done 🙂 Who wants to help as a challenge to make my project to work? any help is appreciated! ---
**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\ **Post date:** [May 7, 2012, 10:01pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/5 "2012-05-07T22:01:15Z")
To send a MIDI message you need to use:- ```arduino void noteSend(int cmd, int data1, int data2) {   cmd = cmd | midiChannel;  // merge channel number   Serial.write(cmd);   Serial.write(data1);   Serial.write(data2); } ``` Having first set ```arduino Serial.begin(31250);      // MIDI speed ``` In the setup() and have defined midiChannel as a global variable and set it to what channel you want. Note channel 0 is what MIDI software calls channel 1. > How do i " define" midi\_note\_on and Midi\_note\_off ? To play a note use:- ```arduino noteSend(0x90, note, vol); ``` and to stop it use:- ```arduino noteSend(0x80, note, 0x00); ``` or ```arduino noteSend(0x90, note, 0x00); ``` Where note is the MIDI note number and vol is the volume of that note. ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 5, 2021, 7:48pm UTC](https://forum.arduino.cc/t/fix-code-error/101942/6 "2021-05-05T19:48:14Z")
Closed on May 5, 2021, 7:48pm UTC