empowering creative people

H2OhNo! ATtiny Dev Board / Water Alarm

SKU: DEV-12069

$18.22 AUD, inc GST
$16.56 AUD, exc GST

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H2OhNo! ATtiny Dev Board / Water Alarm
18.22 AUD

SKU: DEV-12069

$18.22 AUD, inc GST
$16.56 AUD, exc GST
Shipping Offer


  • $6.95 Standard (2-4 days, tracked)
  • $8.95 Express (Overnight*, tracked)
  • $3 Economy Post* (3-7 days, no tracking)
  • FREE Pickup (Newcastle only)

Shipping costs may increase for heavy products or large orders.

Exact shipping can be calculated on the view cart page.

*Conditions apply, see shipping tab below.

The H2OhNo! is a water sensor alarm kit that you build yourself. When water is detected across the sense pins an alarm goes off and an LED starts blinking. If you’ve ever had a water heater explode or tried to create submersible electronics you know how important it is to be able to detect when water is around!

Underneath the default function of H2OhNo! is a small but powerful development board for the ATtiny85 microcontroller. The board includes a buzzer, LED, a coin cell battery, and the ability to detect analog and digital sensors. This mixture of parts creates a great low-cost tool to learn how to program and sense things!

This board can be re-programmed to be an Annoy-A-Tron (originally made by Think Geek). Please annoy respectfully, otherwise your board may get demolished.

Note: Please check the hookup guide below for helpful tips and assembly instructions.

Kit Includes:

  • 1x H2OhNo! PCB
  • 1x ATtiny85 (Pre-Programmed)
  • 1x 20mm Coin Cell Battery Holder
  • 1x CR2032 Coin Cell Battery
  • 1x Slide Switch
  • 1x 2kHz Piezo Speaker
  • 1x 8-pin DIP Socket
  • 1x Super Bright Red LED
  • 2x Jumper Wire
  • 1x Capacitor 0.1uF


Documentation and Resources:

Product Comments

Exact shipping can be calculated on the view cart page (no login required).

We deliver Australia-wide with these options:

  • $3 for Small Items (3-7 days, not tracked, only available on selected small items)
  • $6.95 for Standard Post (2-4 days, tracked)
  • $8.95 for Express Post (Overnight for Australia Post Next Day Network, tracked)
  • Pickup - Free! Only available to customers who live in the Newcastle region (only after we email you to notify your order is ready)

International Orders - the following rates are for New Zealand and will vary for other countries:

  • $11.49 for Pack and Track (3+ days, tracked)
  • $16.50 for Express International (2-5 days, tracked)

If you order lots of gear, the postage amount might increment based on the weight of your order.

Our physical address:

Unit 18, 132 Garden Grove Parade
NSW, 2289

Please checkout our customer service page if you have other frequently asked questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.