Uploaded August 2020 | Updated September 2026, 1 week ago

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Features:
- the timer is always enabled and remains ready in deep sleep mode
- low power modes used as often as possible to save energy
- 500mAh LiPo cell should last for 2-3 years depending of how often the timer will be actually used
- backlight typically is used only for 15 seconds, can be removed completely
- deep sleep counter is used in countdown mode to save energy, it is not very accurate,
can be replaced by regular sleep in case of issues
- could't decide which font should be used so finally there are 4 looks (4 fonts, 2 progress indicators)

BoM:
- Arduino Pro Mini
- HX1230 96x68 pixel LCD
- button
- buzzer or mini speaker
- 100ohm resistor - 2 pcs

To consider:
- buzzer/speaker should be connected via transistor
- lithium battery charging PCB could be considered

Timestamps:
0:00 - Hardware
0:38 - Demonstration
5:27 - Power consumption tests

Project code:
github.com/cbm80amiga/HX1230_CountdownTimer

If you find it useful and want to buy me a coffee or a beer:
paypal.me/cbm80amiga