51 microcontroller DOIT Pomodoro timer

18650 circuit comes from: simple 18650 battery charger, emergency power bank/power bank. - Lichuang EDA open source hardware platform (oshwhub.com)

The solution is not verified

Instructions for use:

When the LED is flashing, you can long press the only button to set the timing time. The timing time is expressed in binary, and the maximum timing time is 32 minutes.

The switch button adopts ergonomic design. The button is placed 4.5CM away from the right side of the PCB, and the switch is placed 5.5CM away from the right side of the PCB. In this way, using the right hand to operate the timer will give you a good experience.

2021/12/2 First verification

BUG found:

1. The charge and discharge chip key cannot be activated normally (pull down for a long time and the power chip cannot always be activated)

2. The current required by the device is small, more than twice the minimum sleep current (40ma) of the power chip, resulting in the inability to use the battery power supply normally.

Verified:

1. Basic Pomodoro function

Recommendation: Do not use some circuits of the power bank: please plug it in and use the current version of the Pomodoro (flying wires are required to allow the power supply to directly supply power to the microcontroller from typeC, bypassing the power chip)