See this PureData (Pd) instrument with input from an LDR controlled 555

Hi, i made a simple musical (erhem) instument with Pure Data (aka. Pd). I also built an electronics component of it, which is a 555 timer chip, who's blinking is responds to the ambient lighting conditions.

An light-dependant-resistor (LDR) controls the blinking behaviour of the 555, an Arduino reads the chip (there is also a LED as an indicator), and sends it over serial to Pure Data's comport -object. The Pd instruments uses the pulse data to modulate a sine-wave oscillator. A sawtooth oscillator is mixed in for a good measure.

Here is a little video

The Arduino code is as simple as

const int inputPin = A0;

void setup() {
  pinMode(inputPin, INPUT);

void loop() {
  int v;
  v = analogRead(inputPin);