Two microcontroller modules
Sound alarm controller is complete, mounted and connected.

This simple unit controls three sound signals; beep, siren and buzzer. Each sound signal will only be given once when a new alarm is triggered, the input must remain clear for at least four seconds for that signal to rearm. A beep is given every six minutes if an alarm is active, as a reminder. The sound LED flashes when a sound alarm is active; once for signal 1 (beep), twice for signal 2 (siren) and three times for signal 3 (buzzer), this flashing pattern is repeated.

Table of content



  1. 100 ms siren
  2. One second siren
  3. Three seconds buzzer



  1. Signal: Beep
  2. Signal: Siren pulse
  3. Signal: Buzzer pulse


  1. Siren
  2. Buzzer
  3. Sound LED
  4. Heartbeat signal

D-Sub 9-pin

  1. GND
  2. 5v
  3. Trigger signal: Beep
  4. Trigger signal: Siren pulse
  5. Trigger signal: Buzzer pulse
  6. Siren output
  7. Buzzer output
  8. Sound LED
  9. Heartbeat signal

Schematic drawing

Sound alarm circuit
Schematic drawing for the sound alarm controller; with AVR ATtiny2313. LEDs not included.

Source code


Simple unit to control three sound signals, written with BASCOM-AVR.

Master Releases

0 0 0 v1.0 Visual Basic 5 months ago

Image gallery

Parts list

Project: Sound alarm control unit by Thomas Jensen is licensed under CC BY-SA 4.0 with attribution required.

Similar resources

  •   Created Jul 22, 2006
  •   Last modified 5 days ago
  • Project status: Scrapped