Short update on the IR sensing equipment

Hey all! It's been a while - mostly due to the fact that my subsystem is waiting on the most important parts - VIBRATIONAL MOTORS!

We've purchased them from a US company, but there were a couple of complications in the purchasing bureaucracy that has led their shipping to be delayed. In the mean time, though, I've been learning JavaScript for use in NodeJS, which is what we'll be using in the LeapMotion interface. The source I have been using is Eloquent Javascript, quite a useful resource, and I'll be moving on to Node soon enough :)

Furthermore, I've been prototyping the infrared ("IR") sensors that Ray had left over from some design units from the last couple of years. These work quite well in terms of voltage - an Arduino can easily deal with them. However, there were problems we encountered in the process.

Firstly, the IR emitter itself is not strong. The receiver was not able to pick up the response from it very well. Instead, we substituted an IR LED. This was able to give a much stronger response that we could read from the Arduino. Next, the ambient light of a room can affect the response, and thus needs to be taken account in the code. Lastly, the colour of the object being put in front of the sensor matters as well - black is not a good colour for IR sensing as it absorbs so much of it!

Thus, we used a bit of a hack to work out if it was close to something or near something. See the short code snipped below:

#define IRreceive A1 
int IRinitial;
void setup() { 
Serial.begin(9600); 
pinMode(IRreceive, INPUT); 
delay(100); 
IRinitial = analogRead(IRreceive); 
} 

void loop() { 
long IR; IR = analogRead(IRreceive);
 Serial.print("NUMBER: ");
 Serial.println(abs(IRinitial - IR)); 
}

The initial read of the IR sensor is used to assess the ambient light of the room. This is then used to compare to response we receive from the sensor. The response to most colours is usually higher. However, for black, it does not sense that it has been put close to the IR receiver until it is pretty much covered - in which case it will give an even lower response. Thus the need for the in abs the code.

Once the motors have come in, I'll be working on making these IR sensors send information to them and hopefully emulate some sort of haptic feedback.