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Coin Cell Challenge Entries

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97 projects
10.1k
58
54
If you have a lot of time, you can decide your position on Earth just using watches and eyes. Or RTC and LDR.
Project Owner Contributor

Light level geolocator

jaromir.sukubajaromir.sukuba

544
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

2.7k
18
19
A minimalist 1.5V coin cell led tree with all components and power source confined within a mini breadboard.
Project Owner Contributor

Joule Thief Mini Christmas Tree

Chris ChungChris Chung

2k
8
3
Call me Slow-on-the-Draw if you like, but I think there's a lot to be learned from this project even if it's a me-too.
Project Owner Contributor

Yet Another Fidget POV (YAFPOV)

doctekdoctek

7.9k
95
113
An Arduino-based watch using 97 LEDs to show the time.
Project Owner Contributor

LiquidWatch

CFCF

6.7k
26
36
A persistence of vision (POV) display with five 0805 LEDs piggy back on an ATTiny13.
Project Owner Contributor

Tiny POV

Jens HaukeJens Hauke

402
2
2
Hateful electrons with fearless mosfets join forces against elements
Project Owner Contributor

picoSTING

Robert MatejaRobert Mateja

1.1k
433
4
My entry to the Hackaday coin cell challenge: A circuit that turns LEDs into miniature supernovas that light up and explode.
Project Owner Contributor

LED Supernova

cls-02cls-02

305
3
3
A wireless node to detect door opening.
Project Owner Contributor

WIRELESS_DOOR_SENSOR

texanetexane

66.2k
414
399
Low power Arduino based (smart)watch
Project Owner Contributor

Chronio

Max.KMax.K

484
255
4
A BCD binary clock that fits inside of a jar
Project Owner Contributor

Binary desk USB jar clock

Marius TaciucMarius Taciuc

448
6
5
Small electronic cricket using the common CMOS 74HC14N
Project Owner Contributor

Electronic Cricket

AlexisAlexis

4k
12
26
An Arduino powered birthday reminder device that'll wish you happy birthday for 50 years on a single CR2450 coin cell.
Project Owner Contributor

Birthday Alarm That'll Run for 50 Years!

Vishnu MohananVishnu Mohanan

1.9k
21
29
Small sized 555 timer based piano.
Project Owner Contributor

555 piano

Alexander RyzhkovAlexander Ryzhkov

4.9k
39
34
Arcade games on the Micro:bit
Project Owner Contributor

Micro:Boy

deʃhipudeʃhipu

22.3k
229
210
A handheld game console programmable with (Micro/Circuit)Python.
Project Owner Contributor

µGame

deʃhipudeʃhipu

1.3k
15
12
A drink coaster which changes color based on a cups temperature
Project Owner Contributor

Thermal Coaster

Ray OlsenRay Olsen

4k
17
16
Make Yourself Stand Out by Building a Digital Business Card using an Arduino, OLED/LCD screen and Coin Battery
Project Owner Contributor

Coin Battery Powered Digital Business Card

lagunacomputerlagunacomputer

6.5k
76
60
Low Power Temperature/Humidity Monitoring
Project Owner Contributor

Gecko Node - Wireless Low Power Sensor

Max.KMax.K

574
4
2
A small circuit inside an enclosure, both optimized to resist a hit to the ground
Project Owner Contributor

Airsoft sonic grenade

EduardEduard

6.8k
59
52
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

4.2k
41
41
The Micro TV-B-Gone is based off of Adafruit's original TV-B-Gone kit, except made to be as small as possible, using an LIR-2032 coin cell.
Project Owner Contributor

Micro TV-B-Gone

Nicholas JunkerNicholas Junker

123.9k
1.3k
662
A family of tiny robots, each with their own way of life.
Project Owner Contributor

Tiny robot family

shlonkinshlonkin

3k
18
13
Thermometer, stopwatch, step mash tool, boiling and hop additions controller in a compact instrument !
Project Owner Contributor

BrewBuddy

Marcelo BarrosMarcelo Barros

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