A few little led throwies.

My new PSoC dev kit just arrived. This should be fun!

Well thankfully all the modules are finished, now just need to mount the led and sensor units and install!

Videos and pictures to follow.

Getting there, only 8 to go. Down to about 12 minutes a board now.

…28 to go.

Well things are hotting up round here with the impending start of the GI festival. With each passing day I get roped into assisting with more and more shows!
There’s some wonderful stuff coming up, including A Typical Root, Vestiges Park and the Beer and Pub Project. See the previews at Glasgow Internationa

Guilherm asked to see a schematic for the IR sensors, so i’ve knocked a quick one up in Eagle for anyone else who’s interested. In the circuit, in its most basic form, the IR led is always on, connected to 5volts with a suitable resistor for the IR diode you are using in relation to the power supply.The IR sensor is connected in the same way, i found a 10k resistor worked in this case, but play arround with different values as it will affect is performance.

Both the IR led and sonsor should be connected to ground.

Between the resistor and the sensor, a jumper wire is connected to what ever you are using to read the sensor. This can be an analogue comparitor connected to an led circuit, or in my case in the videos below. an analogue input on the Arduino, either directly or via a demultiplexor.

Simple arduino code to read sensor and send to serial/USB.

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

void loop()
{
Serial.println(analogRead(5));
delay(20);
}

Simple Arduino code to read sensor and switch on an LED connected to Pin 8:

//works between 200 and 300 threshold with 5mm perspex.
//direct light triggers sensor and sensor only works with perspex when inverted, trigger = off.
int ledPin = 8;      // LED connected to digital pin 9
int analogPin = 5;   // potentiometer connected to analog pin 3
int threshold = 300;

void setup()
{
pinMode(ledPin, OUTPUT);   // sets the pin as output
Serial.begin(9600);
}

void loop()
{

if (analogRead(analogPin) < threshold) {
digitalWrite(ledPin, LOW);  // turn LED ON
} else {
digitalWrite(ledPin, HIGH);
Serial.println(analogRead(analogPin));
}

}

In this code, the led is switched on when the sensor value exceeds a certain reading, but could be adapted to dim an LED using PWM very easily. At the moment i have 16 sensors connected via two 4051 demultiplexor IC’s, connected to two analogue inputs on the arduino, and several digital pins to control which pins are read on the 4051. The Arduino then pumps the sensor readings out to a TI 5940 led controller as PWM signals to control the LED’s.

Hope this helps  Guilherm!

I’ve been playing arround with ideas for an interactive touch screen LED surface for a while now, mainly using capacitive touch sensor’s and infra red proximity sensors, both of which are cheap and relatively simple to implement, especially on prototyping enviroments like arduino.

While the sensor stuff isn’t too exciting too look at just yet, since all I’m doing is reading the returned sensor data through the Serial Monitor, I thought I’d post up a sample of the LED matrix that the sensors will end up being used to control.

Grab yourself a beer and some popcorn, and prepare yourself for a mildly interesting video of a scrolling wave pattern… and then Conways “Game of Life”, which is a slightly modified version of of the example from Andrew on the Arduino forums.