The T-Watch 2020 is a real connected watch built around the ESP32 SoC (ESP32-DOWDQ6) that can be freely programmed with C ++ Arduino, MicroPython or Blockly code. The design is very close to the Apple Watch. Unlike other T-Watches, no expansion slot is available. It is therefore impossible to connect sensors or actuators via the I2C bus.
Specifications for a new version are available on LiLyGo’s official GitHub repository but does not appear to be released yet at the time of writing. In case of error, do not hesitate to use the comments to report an error
2020 T-Watch Specifications
The technical specifications of two versions are detailed on LiliGo’s Github repository.
Currently, it looks like version 2 is still in the development stage. If we look at the comparison table below, version 2 should make the following changes:
| New functions | Removed functions (to be confirmed) |
|
|
The comparative table of the two versions of T-Watch 2020.
v1 v2 Programming, debugging Bluetooth 4.2 BLE/BR/EDR 3-axis (BCK / WS / DOUT) Standard GB/T 18287 Bracelet
Version
T-Watch 2020
T-Watch 2020
Processor
ESP32-DOWDQ6
Flash
16MB
SPRAM
8MB
USB-> TTL converter
CP2104
Connectivity
WiFi 802.11 b/g/n
Accessories
User button
No
No
SD card reader
No
Yes
Power controller
AXP202
AXP202
GPS
Air 530
Power supply pin (AXP202)
LDO4
Accelerometer
BMA423
RTC clock
PCF8563
Vibrator (motor)
4
?
External I2C bus (SDA / SCL)
21/22
I2S audio interface
26/25/33
?
IR (send only)
13
4
Extension connector
No
TFT screen
ST7789V
Screen resolution (HxV)
240×240
Screen dimension
1.54 ”
Touch screen driver
FT6236
Camera
No
Interruptions
AXP202
35
35
Power button
37
37
Accelerometer
39
39
Touchscreen
38
38
Useful links
Pin definition file
GitHub
GitHub
Other characteristics
Weight
58.5 g
Dimensions (L, H, e) mm
40 x 47.45 x 13
Li-Ion battery
380 mAh, 3.7V
Supplied accessories
USB-C charging cable
The 3.7V Li-Ion battery with a capacity of 380mAh is very easy to replace by opening the back of the watch case. No special tools are required.
T-Watch 2020 ESP32 pinout
Here is the pin spotting of the ESP32 of the two versions of T-Watch 2020.
| Function | T-Watch 2020 V1 | T-Watch 2020 V2 |
|---|---|---|
| ESP32 | ESP32-DOWDQ6 | ESP32-DOWDQ6 |
| Flash | 16MB | 16MB |
| SPRAM | 8MB | 8MB |
| Touch screen driver | FT6236 | FT6236 |
| TFT screen driver | ST7789 | ST7789 |
| GPS module | Air530 | |
| TFT Size | 240×240/1.54 | 240×240/1.54 |
| TFT RST | N/A | N/A |
| TFT MISO | N/A | N/A |
| TFT MOSI | 19 | 19 |
| TFT SCLK | 18 | 18 |
| TFT DC | 27 | 27 |
| TFT CS | 5 | 5 |
| TFT BackLight | 12 | 12 |
| SDA SENSOR | 21 | 21 |
| SENSOR SCL | 22 | 22 |
| FT6236 SDA | 23 | 23 |
| FT6236 SCL | 32 | 32 |
| FT6236 RESET | 4 | AXP202 EXTEN Pin control |
| BMA423 Interrupt | 39 | 39 |
| FT6236 Interrupt | 38 | 38 |
| PCF8563 Interrupt | 37 | 37 |
| AXP202 Interrupt | 35 | 35 |
| GPS TX | 26 | 26 |
| GPS RX | 25 | 25 |
| WAKEUP GPS | 33 | 33 |
| IR Send | 13 | 4 |
| SD MISO | 2 | |
| SD MOSI | 15 | |
| SD SCLK | 14 | |
| SD CS | 13 |
AXP202 Power Controller Pinout
The AXP202 power controller allows peripherals to be powered independently from the ESP32.
Entirely controlled via the I2C bus (and integrated into the TTGO.h library), the AXP202 is used to power the watch peripherals without going through the ESP32.
| AXP202 output | T-Watch 2020 V1 | T-Watch 2020 V2 |
|---|---|---|
| DC2 | Not used | Not used |
| DC3 | ESP32 power supply. Do not deactivate !! | ESP32 power supply. Do not deactivate !! |
| LDO1 | Not available | Not available |
| LDO2 | Backlight, TFT screen backlight | Backlight, TFT screen backlight |
| LDO3 | TFT / TOUCHT screen | |
| LDO4 | Not used | GPS module |
| EXTEN | Not used | TOUCH RESET EN |
- T-Watch. Simplified code for shutdown and wake-up with BMA423 or AXP202 of the ESP32
- T-Watch. Sleep and wake-up ESP32 with BMA423 accelerometer or AXP202 button
- T-Watch. Menu, pages, navigation between screens with TFT_eSPI
- T-Watch. Draw Mandelbrot or Julia fractals with an ESP32 and LVGL + TFT_eSPI
- T-Watch. Display XBM (TFT_eSPI) and C++ (LVGL) images. ESP32, Arduino compatible
