An annoying little thing, really
Here's a tiny pcb that you can stash somewhere and annoy people. Where's that chirping coming from?
It uses an LED, piezo buzzer, ATTINY13 Atmel microcontroller, a very small amount of Arduino code, and a coin cell battery that should last about a week.
Battery life could be improved, with longer sleep times.
The device has but one function: sleep, then wake up periodically and blink and chirp, then go back to sleep.
You can program the chip using a pogo pin programmer, like this one from Sparkfun
| Board ID | Part Number | Description | Sources |
|---|---|---|---|
| IC1 | ATTINY13A-SU | SMT Atmel Attiny 13a | Mouser |
| LED1 | HT-121UYG-4739 | 0603 20ma bright yellow SMT LED | Mouser |
| SG1 | PKMCS0909E4000-R1 | 9MM square 4KHz piezo buzzer, SMT | Mouser |
| R1 | 1M | 0603 1 Meg ohm SMT resistor | Mouser, Newark, Digikey |
| R2 | 1300 | 1206 1.3K ohm SMT resistor | Mouser, Newark, Digikey |
| CR-2032 | CR-2032 | 3.3v lithium battery | Mouser, Amazon |
| Holder | BAT-HLD-001 | SMT battery holder | Mouser |
Eagle CAD files are in /board in case you want to iterate
You can also order these from OshPark
