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Coin Cell Challenge Entries

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97 projects
538
4
7
Coin cell powered 555 timer with ultraviolet LED coated with glow in the dark paint to mimic a firefly.
Project Owner Contributor

Fireflies

Jux CrowJux Crow

356
6
5
A gift tag for the holiday season including a 7x10 LED matrix, which can show a personal text message.
Project Owner Contributor

Happy Holidays gift tag

CFCF

7.2k
91
105
Ever since I have my own company I wanted to have a PCB business card. What not add an OLED display to it?
Project Owner Contributor

Electrocard

Michael TeeuwMichael Teeuw

1.3k
14
12
A drink coaster which changes color based on a cups temperature
Project Owner Contributor

Thermal Coaster

Ray OlsenRay Olsen

6.5k
58
50
A low cost ultra-low-power small-sized high accuracy temperature logger for use in scientific research.
Project Owner Contributor

Low-cost/power/size temperature logger

NikosNikos

808
3
6
The business card of a common singing bird.
Project Owner Contributor

Chiffchaff Card

Adam AntokAdam Antok

819
4
4
A battery powered, periodic infrared beacon for a geocaching puzzle
Project Owner Contributor

Low power IR beacon

piotrb5e3piotrb5e3

5.1k
73
72
whowhow. whowhow. - formally known as purple rider
Project Owner Contributor

K.I.T.T. - KNIGHT RIDER badge/brooch

davedarkodavedarko

44.4k
265
212
Multi-year always-on LED replacements for gaseous tritium light sources
Project Owner Contributor

TritiLED

Ted YapoTed Yapo

303
6
11
Here I have a Maker Gummi Bear that can be worn as an electronic badge. It contains LEDs and is powered by a single coin cell battery.
Project Owner Contributor

Maker Gummi Bear

RachelRachel

47.7k
174
107
This project using an ESP8266 to find the password of a WiFi access-point with PBC enabled.
Project Owner Contributor

WiFi cracker ESP8266(PBC)

Sagar NaikSagar Naik

1.9k
21
28
Small sized 555 timer based piano.
Project Owner Contributor

555 piano

Alexander RyzhkovAlexander Ryzhkov

731
6
12
PlexChar it's a mini led matrix board with tiny controller
Project Owner Contributor

PlexChar

Alexander RyzhkovAlexander Ryzhkov

26k
89
110
If you like happy, easy to build projects, this is not for you. This project is only for people who like to be miserable and frustrated.
Project Owner Contributor

An Unfortunate SMD Project

MakersBoxMakersBox

342
4
4
Small and cheap LED lights that turn on when its dark. Powered by a coin cell battery.
Project Owner Contributor

Tiny moon lights

Prof. FartsparkleProf. Fartsparkle

919
4
2
Silicon Laboratories inc. sell MCU named Busy Bee, I decided to give it a try by transforming one in desperate firefly.
Project Owner Contributor

desperate firefly

JacquesJacques

862
10
7
CR2032 Coin Cell LCD Projector. Digispark Attiny85 module, LCD panel harvested from ebay mp3 player.
Project Owner Contributor

Coin Cell LCD Projector

ChallengingStage888ChallengingStage888

752
7
6
Lorentz dreams about metal horses
Project Owner Contributor

pic-o-matic

Robert MatejaRobert Mateja

13.7k
625
90
wearable UV Index & weather sensor
Project Owner Contributor

UV-badge

x-labzx-labz

1.8k
14
13
Small battery for your ESP8266 devices.
Project Owner Contributor

Coin Battery Shield for D1 Mini

deʃhipudeʃhipu

341
1
4
Animate the famous SuperMario's mushroom
Project Owner Contributor

Mushroom on wheels

PixJuanPixJuan

37.8k
184
125
Mesh of sensors, zigbee, custom RF, BT, wifi, all to MQTT Gateways on Raspberry Pi with database, dashboard and webapps.
Project Owner Contributor

Home Smart Mesh

WassimWassim

12.4k
24
15
This project describes the use of a coin cell for powering the Esp8266 by building a remote control for Phillips Hue Lights
Project Owner Contributor

Solved: Esp8266 powered by coin cell

GelstronicGelstronic

385
2
2
Hateful electrons with fearless mosfets join forces against elements
Project Owner Contributor

picoSTING

Robert MatejaRobert Mateja

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