Fig. Lilygo T-Watch 2020 (Lilygo)
Jan Dytrych has started a software project to be able to display data from SignalK and receive alarms with a smart watch. Not just any common clock under Android is used as a smart watch. He uses the smart watch Liligo T Watch 2020. The special feature of this clock is that it has an ESP32 installed as a processor and can be programmed via the Arduino IDE or PlatformIO. The manufacturer Liligo supports the watch with a number of libraries that make programming much easier.
The Liligo T-Watch 2020 has the following components:
Fig. Hardware Lilygo T-Watch 2020 (Lilygo)
- CPU: ESP32, dual-core MCU, 240MHz
- FLASH: QSPI Flash 16MB
- SRAM: 520KB SRAM / PSRAM 8MB
- WiFi 802.11bgn 2.4GHz
- Bluetooth 4.2 BR/EDR, BLE
- Display: 1.54 inch color TFT, capacitive touchscreen, 240 x 240 pixels
- 3-axis accelerometer BMA423
- RTC clock: PCF8563
- IR receiver
- speaker
- Button: power button
- USB to TTL: CP2104 (Micro USB)
- Lithium battery 380 mAh, 3.7 V, exchangeable Type: YX-W9A
- Operating temperature range: -40 ~ +85 degrees
- metal body
- Water tightness none
- Silicone strap 270mm
- Weight: 58.5g
A USB cable is supplied with the T-Watch 2020, which can be used to charge the watch and transfer programs. The watch has an aluminum metal case and the design is based on the Apple I-Watch. The watch is comfortable to wear with the non-replaceable silicone strap. The only weak point is that the watch is not waterproof.
Table of contents
Properties of the firmware
The firmware for the clock is at GitHub hosted and has the following features:
- Clock function main screen with status bar
- Setup screen for Date, Time, Alarm time, WiFi, SignalK
- Custom screens for values from SignalK
- SignalK events wake up the clock and display messages
- Sleep mode with display off for long operation up to 24 hours
- Wake up the display with a tap or twist of your wrist
- Day/night mode via double tap
- Language customization via source code
- pedometer
Fig. Start screen, warning message and SignalK values
Settings and Configuration
The basic settings can be made on the watch via the display. The program is available for designing user-defined image content for SignalK values TWatchSK Designer for Linux, Mac and Windows. This makes it very easy to create new display pages for SignalK and transfer them to the clock via a USB connection. The configurator allows a wide variety of representations and color selection for the values to be displayed.
Fig. TKWatchDesigner with result
Conclusion
With his open source software project, Jan Dytriych has developed a cool application with which it is possible to view and monitor data from SignalK on the wrist. The alarm messages in particular are a useful function for being informed about limit value violations. The project is very well documented on Github and those interested should find all the necessary information. With the T-Watch 2020, Lilygo has provided interesting hardware for little money, with which a large number of projects can be implemented. The use of the popular CPU ESP32 simplifies software development for makers, as they can develop in familiar environments with known knowledge. The only downside of the T-Watch 2020 is that it is not waterproof. Whether this is a KO criterion remains to be seen in practical use on the boat. Let's hope that Liligo will also release a waterproof T-Watch in the future.
Left
Project Homepage: https://github.com/JohnySeven/TWatchSK
TWatchSK Designer: https://github.com/JohnySeven/TWatchSKDesigner#twatchskdesigner
Lillygo T Watch 2020: http://www.lilygo.cn/prod_view.aspx?TypeId=50053&Id=1380&FId=t3:50053:3
pictures
Fig. Lilygo T-Watch 2020 (Lilygo)
Fig. Opened cover, lithium battery on the right