Go Down

Topic: Please help me with midi output from ir distance sensor! (Read 948 times) previous topic - next topic

jimpendo

Hi Everyone.

I'm are doing an lighting installation for an event in Sydney this coming friday, and kinda freakin because a component of the work is using an arduino, and naturally I jumped right in with the "ive seen others do it, so Im sure I can" attitude... always a positive attitude to take imo.

We have 5 prox sensors running into an arduino uno, which is spitting out midi over tx and through a midi-usb converter and into the computer, which is controlling madrix for the lights.

So basically... you can see from the code below what I am starting with (full credit to Noah Stahl whos code this essentially is). The next thing I need to is add in 4 more sensors.. can i do that just by defining them at the start and then mirroring the code below?

Secondly, the sensors are very jumpy, so I need to do some mad smoothing, I have looked around on how to do that but i'm at a bit of a loss...

And thirdly, we just need one more control (just a note change or anything like that, not continuous controll) that fires once every two minutes, how would I do that do you think?

Heres the code i'm working with:

Code:
//  Noah Stahl
//  5/25/2011
//  http://arduinomega.blogspot.com
//  Arduino Mega 2560
//This sketch is used to test the Sharp Long Range Infrared Sensor.
//The sensor output is attached to analog pin 15. Once the distance
//is calculated, it is printed out to the serial monitor.

#define sensorIR 1               //Must be an analog pin
float sensorValue, inches, cm;    //Must be of type float for pow()

void setup() {
  Serial.begin(31250);
 
}

void loop() {
  sensorValue = analogRead(sensorIR);
  inches = 4192.936 * pow(sensorValue,-0.935) - 3.937;
  //cm = 10650.08 * pow(sensorValue,-0.935) - 10;
  delay(100);
 
Serial.write(0xb0); // CC message for channel 1
  Serial.write(0x5); // or what ever CC number you want to write to
Serial.write(int(inches) & 0x7f); // keep the inches from going over 127
}

And here is our installation website http://digitalwattle.co.nz/
There is a sweet test video if you want to see what we are doing!

Thanks to anyone who replies, I have to say I'm loving this community, will chuck the arduino logo on our sponsors list on our installation lightbox!

Cheers,

James

AWOL

#1
May 24, 2012, 08:10 am Last Edit: May 24, 2012, 08:17 am by AWOL Reason: 1
The simplest way is not to replicate code, but to use a for loop.
Make sensorIR an array, and in "loop" have a for loop that addresses each in out pin in turn.
Smoothing could be any number of algorithms, and the best will depend on the sensor.
Try a rolling average over, say 10 readings.

Another technique, which uses less memory, is to keep a ruuning value, and for each new reading, multiply the running total by, say 9/10 and add 1/10th of the new reading.

Please do not cross post - I have deleted the other thread on this subject.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

KingOfSka

Are you using SHARP IR sensors ? if so did you put a bypass capacitor as suggested on the datasheet ?

daatse

the third question should look something like i hope this helps

Code: [Select]

#define delay 120 //(in seconds)
#define duration 2 //(duration of tone in seconds)
unsigned long time;
unsigned long prevtime;
unsigned long starttone;
boolean tone = False;

time = millis()
if (time-prevtime>=(delay*1000))
{
Serial.write(0x90); //note on on channel 0
Serial.write(0x3C); // middle C (not 100% sure)
Serial.write(0x45); // velocity
Prevtime = time;
starttone = time;
tone = TRUE;
}

if (time-tonetime>=(duration*1000)&&tone==TRUE)
{
Serial.write(0x80) ;// note off
Serial.write(0x3C); // middle C
Serial.write(0x45); // velocity (does't matter what you fill in here)
tone=FALSE;

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy