Duinothrowie

A coin-cell powered ATTiny board with popular peripherals (USB, potmeter, slide/tact switch, piezo buzzer, LED) to jump-start tiny projects.

Description

Me and some friends run into the same problem over and over; you want to create;
- a distributed group of "dumb" nodes that interact together and form something awesome
- a fridge door alarm
- something else that's small, runs on a battery and is inexpensive

BUT
- you don't want to start from scratch
- you don't want to spend evenings soldering the same repetitive stuff
- you don't want to use an existing development board which are usually costly, large, and don't have some simple (user) inputs and outputs

OR

You want to teach people electronics and software development without giving them (1) a development board (2) a starter kit with breadboard, jumpwires and miscellaneous parts.

This is why Duinothrowie was born. It's about the size of a 2032 coin cell, and has a holder for one on the back.

Details

Features:

- Size: 35 x 26 x 8mm

- ATtiny85 Microcontroller with Micronucleus USB-bootloader.

- CR2032 coin cell holder on the back (can run for weeks or even months when using the micro's sleep functions)

- Transistor (NPN in current sink configuration) for switching larger currents

- All peripherals wired so the impact is minimal if you want to connect other devices

- Micro USB connector for power and uploading firmware

- All micro pins and GND and VCC broken out on SMT pads

- 4 mounting holes (3mm) for easy mounting

User input

- Tact switch

- SPST slide switch

- Potentiometer (100K)

User output

- Piezo buzzer

- Bright LED

To be honest, I can't get the bootloader to work properly (it freezes the USB-hub of my MacBook Pro sometimes) and this is a little above my head as well. I'm not sure if this is a software or hardware issue.

I can imagine this being a really nice sub-$10 starter-board for a lot of people (you could essentially use them as throwies!) but that would require perfect operation and meticulous documentation, application examples etc.

Right now, I don't have time to develop this project further; if someone wants to pick this up, or create something similar, feel free to do so.

Files

gve-duinothrowie-v2.sch

EAGLE schematics

sch - 607.32 kB - 12/24/2017 at 16:02

Download

gve-duinothrowie-v2.brd

EAGLE board

brd - 110.05 kB - 12/24/2017 at 16:02

Download

gve-duinothrowie-v2-brd.pdf

Adobe Portable Document Format - 61.35 kB - 12/24/2017 at 16:02

Preview

gve-duinothrowie-v2-sch.pdf

Adobe Portable Document Format - 33.19 kB - 12/24/2017 at 16:02

Preview

Components

1 × ATtiny85 Microcontroller

1 × Bourns 3314J-1-204E potmeter

2 × BZX84 3.6V Zener

1 × Hirose ZX62-AB5PA Micro USB

1 × KSSG23J12 Piezo buzzer

Discussions

Gregor wrote 04/15/2018 at 15:13

The bootloader is programmed by ISP; after that, USB programming works. It just crashes my MacBook Pro's keyboard (USB hub) sometimes :)

Are you sure? yes | no

Elliot Williams wrote 01/10/2018 at 15:33

Very nice idea, sad to see it not working (yet). I think you've hit on a great use case and basic solution. USB is not the friend of the minimal hack, however. I wonder if you wouldn't have it working right now if you allowed for SPI/ISP programming?

Are you sure? yes | no

Duinothrowie

Description

Details