Built-in project · no microcontroller

555 tone

A 555 astable drives a piezo straight from the output pin, no board and no button. There is no microcontroller in it: the simulator solves the 5 parts as a circuit, so it runs the moment you press Run, and nothing needs compiling.

Runs in your browser. Free, and no account needed.

555 tonelive0.000 s 0.00x
Click to open it in the editor
The circuit itself, running here on the simulator. Press what can be pressed; click anything else to open it in the editor.

How it works

There is no microcontroller in this one, so nothing is compiled: the simulator solves the circuit itself. The file in the editor is the notes that come with it.

sketch.ino
// Mokxi: a 555 astable driving a piezo.
// There is no microcontroller here. Press Run and the simulator solves the
// circuit itself.
//
// f = 1.44 / ((R1 + 2 R2) C) = 1.44 / ((1k + 9.4k) x 100nF), about 1.4 kHz.
// Change R2 or C1 in the properties panel and the pitch moves with them.

Parts list

7 parts, plus the jumper wires. Every one is in the editor's parts bin.

How it is wired

5 connections, pin by pin, read from the circuit itself. Each line is one set of pins joined together, by a jumper wire or a breadboard strip.

  • 5 V: Resistor, 1k Ω pin 2; NE555 timer pin RESET; NE555 timer pin VCC
  • Ground: NE555 timer pin GND; Capacitor, 100 nF pin 2; Piezo speaker pin 2
  • NE555 timer pin TRIG; NE555 timer pin THR; Resistor, 4.7k Ω pin 2; Capacitor, 100 nF pin 1
  • NE555 timer pin OUT; Piezo speaker pin 1
  • NE555 timer pin DIS; Resistor, 4.7k Ω pin 1

Change it and keep it

Open it in the editor, change the circuit or the code, and keep your version in a free account.