Summary of Chronio – Low power Arduino based (smart)watch
Chronio is an Arduino-based, 3D-printed smartwatch focused on low power consumption, using an Atmega328p microcontroller and a 96x96 pixel Sharp Memory LCD. Without WiFi or BLE, it achieves several months of battery life on a 160mAh CR2025 coin cell. Features include time, date, temperature display, a stopwatch, and a Flappy Bird clone. The watch uses a Maxim DS3231 RTC and three 3D-printed side buttons, housed in a slim 10.8mm case compatible with any 22mm watchband.
Parts used in the Chronio:
- Atmega328p microcontroller with Arduino bootloader
- Maxim DS3231 Real Time Clock
- 96x96 pixel Sharp Memory LCD (LS013B4DN04)
- CR2025 160mAh coin cell battery
- 3D-printed case parts (four parts)
- 3D-printed buttons
- PCB with switches activated by buttons
Description
Chronio is an Arduino-based 3D-printed Watch. By not including fancy Wifi and BLE connectivity, it gets several months of run time out of a 160mAh button cell. The display is an always-on 96×96 pixel Sharp Memory LCD. If telling the time is not enough, you can play a simplified version of Flappy Bird on it.
DIY watches often consist of a pcb and screen wrapped in duct tape. I wanted to change that by designing a 3D-printed case. It is closely oriented on the Pebble Time.
DIY watches often consist of a pcb and screen wrapped in duct tape. I wanted to change that by designing a 3D-printed case. It is closely oriented on the Pebble Time.
Hardware
- Microcontroller: Atmega328p with Arduino bootloader
- Real Time Clock: Maxim DS3231 (<2min per year deviation)
- Display: 96×96 pixel Sharp Memory LCD (LS013B4DN04)
- Battery: CR2025 160mAh coin cell
Features
- The ATmega is in Sleep mode for most of the time and only runs once a minute to update the time or if a button is pressed. This reduces the current consumption to 2uA. Sady the display needs a certain pulse every second, which requires a complicated additional circuit. Because of this the current consumption is around 20uA. This still makes for around half a year of battery life.
- User Interface controllable with three side buttons. Buttons are 3D-printed and activate switches on the PCB
- Tells time, date, temperature and battery voltage on the main screen. No additional temperature sensor is needed, because the DS3231 already has one integrated for temperature compensation.
- Stopwatch
- Flappy Bird clone (“That would have been cool in 2013”)
- The case consists of four 3D-printed parts. It has a thickness of only 10.8mm, which is thinner than the Apple Watch. Unfortunately it lacks screen protection.
- Fits any 22mm Watchband
For more detail: Chronio – Low power Arduino based (smart)watch
