Hi Team,
I have taken on a project where I am attempting to use a Reed switch fitted to a bicycle wheel to send midi messages to QLab (Figure 53 show control software) to control the output of LED lights.
The Basic idea being that as a user pedals the bike faster, More lights will light up.
So far I have managed to find a tutorial that shows building a Bike speedometer, Which I have successfully done.
I am now attempting to add to the code so I can use the speed read out to generate Midi messages to send to the control computer Via Hairless MIDI.
My end goal is to get the Arduino spitting out a new MIDI Note on command as the bike passes a certain speed threshold, keeping that note on until the bike passes back below the speed threshold. I also want to have up to ten individual thresholds so I can have 10 channels of lights which come on as the bike gets faster and faster. Again all turning back off as the bike passes back below the threshold.
I am getting messages out of the Arduino but they seem not to be responsive to the speed.
I also get MIDI Messages on channels that I have not mentioned at all and at various velocities, Unsure of why this is.
Here is my code, It compiles and uploads but currently doesn't do what I am aiming for.
Am I going down the right path here?
//calculations
//tire radius ~ 13.5 inches
//circumference = pi*2*r =~85 inches
//max speed of 35mph =~ 616inches/second
//max rps =~7.25
#include <MIDI.h>
MIDI_CREATE_DEFAULT_INSTANCE();
#define reed A0//pin connected to read switch
//storage variables
int reedVal;
long timer;// time between one full rotation (in ms)
float mph;
float radius = 13.5;// tire radius (in inches)
float circumference;
int maxReedCounter = 100;//min time (in ms) of one rotation (for debouncing)
int reedCounter;
void setup(){
reedCounter = maxReedCounter;
circumference = 2*3.14*radius;
pinMode(reed, INPUT);
// TIMER SETUP- the timer interrupt allows precise timed measurements of the reed switch
//for more info about configuration of arduino timers see http://arduino.cc/playground/Code/Timer1
cli();//stop interrupts
//set timer1 interrupt at 1kHz
TCCR1A = 0;// set entire TCCR1A register to 0
TCCR1B = 0;// same for TCCR1B
TCNT1 = 0;
// set timer count for 1khz increments
OCR1A = 1999;// = (1/1000) / ((1/(16*10^6))*8) - 1
// turn on CTC mode
TCCR1B |= (1 << WGM12);
// Set CS11 bit for 8 prescaler
TCCR1B |= (1 << CS11);
// enable timer compare interrupt
TIMSK1 |= (1 << OCIE1A);
sei();//allow interrupts
//END TIMER SETUP
Serial.begin(9600);
}
ISR(TIMER1_COMPA_vect) {//Interrupt at freq of 1kHz to measure reed switch
reedVal = digitalRead(reed);//get val of A0
if (reedVal){//if reed switch is closed
if (reedCounter == 0){//min time between pulses has passed
mph = (56.8*float(circumference))/float(timer);//calculate miles per hour
timer = 0;//reset timer
reedCounter = maxReedCounter;//reset reedCounter
}
else{
if (reedCounter > 0){//don't let reedCounter go negative
reedCounter -= 1;//decrement reedCounter
}
}
}
else{//if reed switch is open
if (reedCounter > 0){//don't let reedCounter go negative
reedCounter -= 1;//decrement reedCounter
}
}
if (timer > 2000){
mph = 0;//if no new pulses from reed switch- tire is still, set mph to 0
}
else{
timer += 1;//increment timer
}
if (mph > 25){ // If we have received a message
MIDI.sendNoteOn(42, 127, 1); // Send a Note (pitch 42, velo 127 on channel 1)
delay(1000); // Wait for a second
MIDI.sendNoteOff(42, 0, 1); // Stop the note
}
if (mph > 15){ // If we have received a message
MIDI.sendNoteOn(50, 127, 1); // Send a Note (pitch 42, velo 127 on channel 1)
delay(1000); // Wait for a second
MIDI.sendNoteOff(50, 0, 1); // Stop the note
}
if (mph = 0){
MIDI.sendNoteOff(42, 0, 1);
MIDI.sendNoteOff(50, 0, 1);
}
}
void displayMPH(){
Serial.println(mph);
}
void loop(){
//print mph once a second
displayMPH();
delay(1000);
}
I am super new to the Arduino world so forgive me if I have completely come at this from the wrong direction...
Any suggestions/ pointers about what I am trying to do would at this point be super apprciated,
Have a great day!
