In this article, you will find the ESP32 pinout of the different versions of T-Watch as well as those of the expansion board. All the drivers and libraries necessary for the integration of the components embedded on the expansion board are already implemented in the TWatch library available on GitHub . Using the official library, there is no need to manually assign pins in the Arduino code.
The official documentation available here is out of date (at the time of writing). If you encounter any difficulties or errors, please let me know via the contact form using the button above.
Pinout of TTGO T-Watch and T-Block ESP32 Core PCB
The Core PCB is pre-installed in the box. It is the motherboard of the T-Watch built on the basis of an ESP32. The board is equipped with an AXP202 power manager also used to manage the power supply of accessories (GPRS modem, LoRa, GPS receiver, etc.) without going through that of the ESP32 (too limited), 16MB of memory flash and 8MB of SPRAM memory.
Aliexpress.com
The T-Block shares the same architecture as the T-Watch. It is the oldest box in the series equipped with a screen (non-touch e-paper).
The T-Bot is a version that incorporates a daughter board on which an HC-SR04 ultrasonic proximity sensor is placed. The T-Block is then installed on a base equipped with a motor to transform the T-Bot into a mini robot! Up to 3 analog sensors can be installed on the expansion board in addition to the HC-SR04 .
| Peripheral | T-Watch 2019 TOUCH | T-Watch-N | T-Block / T-Bot |
|---|---|---|---|
 |  |  | |
| Core | ESP32-DOWDQ6 | ESP32-DOWDQ6 | ESP32-DOWDQ6 |
| Flash | 16MB | 16MB | 16MB |
| SPRAM | 8MB | 8MB | 8MB |
| Screen | TFT ST7789 | TFT ST7789 | e-paper |
| Touch driver | FT6236 | N/A | N/A |
| TFT Size | 240×240/1.54 | 240×240/1.54 | N/A |
| TFT RST | N/A | N/A | N/A |
| TFT MISO | N/A | N/A | N/A |
| TFT MOSI | 19 | 19 | N/A |
| TFT SCLK | 18 | 18 | N/A |
| TFT DC | 27 | 27 | N/A |
| TFT CS | 5 | 5 | N/A |
| TFT BackLight | 12 | 12 | N/A |
| SDA (1) | 21 | 21 | 21 |
| SCL (1) | 22 | 22 | 22 |
| FT6236 SDA | 23 | N/A | N/A |
| FT6236 SCL | 32 | N/A | N/A |
| BMA423 Interrupt | 39 | N/A | N/A |
| FT6236 Interrupt | 38 | N/A | N/A |
| PCF8563 Interrupt | 37 | 37 | 37 |
| Button 1 | 36 | 36 | 36 |
| AXP202 Interrupt | 35 | 35 | 35 |
| Revision | 211-191209 |
(1) The following devices use the I2C bus (default) of the ESP32.
Peripheral T-Watch 2019 TOUCH T-Watch 2019 NO TOUCH T-BLOCK RTC clock PCF8563 PCF8563 PCF8563 3-axis accelerometer BMA423 BMA423 MPU6050 Power Manager AXP202 AXP202 AXP202
Expansion boards available for T-Watch Touch and T-Watch-N
Here is the list of expansion board currently available. The list is continuously enriched.
- Pin Expansion Board (Basic) , 2 x 8-pin expansion connectors providing access to pins 33, 34, 21 (SDA), 22 (SCL) of ESP32 and IO0, IO1, IO2 and IO3 of AXP202 (power manager). This is the board delivered as standard
- GPS M8N
- Motor & Speaker (Pack H329), vibrator + speaker
- MPR121, external touch interface
- SIM800L, modem GPRS
- MP3 , MP3 player
- NFC , contactless reader (note, this is not an RFID reader)
- MAX98357 (Pack H328), oximeter
- S76G Lora + GPS (Pack H327),
- S78G Lora (433 to 470 MHz) + GPS (Pack H397). LoRa modem
- T-Car, can drive up to 3 servo motors via the 1-Wire bus
- T-Quick , can control up to 2 motors in I2C
- Game , joystick and 4 buttons to transform the T-Watch into a Gameboy!
Mounting an expansion board in the T-Watch Touch or T-Watch-N.
See more expansion boards for the T-Watch
Basic Expansion Board expansion board
Expansion board supplied by default is necessary which adds the following functions:
- MicroSD card reader (pin identification below)
- 2 8-pin 2.54mm pitch connectors (for standard jumper)
- ESP32 pins: 33, 34, 21 (SDA), 22 (SCL)
- AXP202 pins (power supply manager): IO0, IO1, IO2 and IO3, EXTEN
- 3x GND
- 2x VCCX 3,5V ~5V
- 1x VDD 3V3
- 1x I2C connector to Molex 53015-0410 standard.
- GND, 26, 25, VCC
- A 4-pin cable fitted with a connector a cable fitted with a Molex 51065-0400 connector is supplied and can be purchased separately
- x1 VBUS solder connector
- x1 connector for LiPo battery to JST standard 2 pins 1.54mm pitch
Basic Expansion Board Pinout
| ESP32 | Function | Description |
|---|---|---|
| MicroSD card reader | ||
| GPIO13 | CS | TF_CS |
| GPIO15 | DAWDLE | TF_MOSI |
| GPIO02 | MISO | TF_MISO |
| GPIO14 | SCLK | TF_SCLK |
| Connector 4-pin , I2C bus | ||
| GPIO25 | I2C | SDA |
| GPIO26 | I2C | SCL |
| 8 pin connector | ||
| GPIO33 | User | |
| GPIO34 | User | |
| GPIO21 | I2C | SDA |
| GPIO22 | I2C | SCL |
SIM800 GPRS modem. Internet connectivity, sending and receiving SMS
Expansion board to send / receive SMS and connect the watch to the internet.
The SIM800 modem is a quad-band GSM / GPRS module that operates on GSM 850 MHz, EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz frequencies. The SIM800L has multiple GPRS slots and supports the GPRS CS-1, CS-2, CS-3 and CS-4 coding schemes.
SIM800L expansion board pinout
| ESP32 | Function | Description |
|---|---|---|
| SIM800L modem | ||
| GPIO33 | TX | UART_SIM_TX |
| GPIO34 | RX | UART_SIM_RX |
| GPIO14 | RST | SIM_RST |
| GPIO15 | PWKEY | SIM_PWKEY |
| GPIO04 | BOOST | SIM_BOOST_CTRL |
| Connector 4-pin , I2C bus | ||
| GPIO25 * | I2C | SDA |
| GPIO26* | I2C | SCL |
| MicroSD card reader | ||
| GPIO13 | CS | TF_CS |
| GPIO15 | DAWDLE | TF_MOSI |
| GPIO02 | MISO | TF_MISO |
| GPIO14 | SCLK | TF_SCLK |
(*) To be checked, may vary between versions
Activation of the SIM800L modem
Use these keys in the config.h file to activate the SIM800L modem support
LILYGO_WATCH_HAS_SIM800L
Useful links
U-blox NEO M8N GPS expansion board
The u-blox GPS of the NEO-M8 series uses simultaneous reception of up to three GNSS systems (GPS / Galileo with BeiDou or GLONASS). It will allow you to retrieve the positioning (longitude, latitude, altitude) as well as the time for your projects.
u-blox NEO M8N GPS module pinout
| ESP32 | Function | Description |
|---|---|---|
| GPS u-blox NEO M8N | ||
| GPIO33 | TX | UART_GPS_TX |
| GPIO34 | RX | UART_GPS_RX |
| Connector 4-pin , I2C bus | ||
| GPIO21* | I2C | SDA |
| GPIO22* | I2C | SCL |
| MicroSD card reader | ||
| GPIO13 | CS | TF_CS |
| GPIO15 | DAWDLE | TF_MOSI |
| GPIO02 | MISO | TF_MISO |
| GPIO14 | SCLK | TF_SCLK |
Activation of the u-blox NEO M8N GPS receiver
Use these keys in the config.h file to activate support for the M8N GPS receiver
LILYGO_WATCH_HAS_GPS
Useful links
U-blox NEO M8 series technical documentation
LoRa expansion board (433 MHz or 868 MHz) + GPS (AcSIP S76GXB)
This expansion board can send and receive LoRa messages and perform GPS positioning. It has an S76G or S78G SiP from the manufacturer AcSIP.
Each SiP has a LoRa SEMTECH SX1276 (for the 863 MHz or 928 MHz band) or SX1278 (433MHz or 470MHz) modem on board.
The S76G and S78G also include a SONY CXD5603GF GPS chip which can receive the GPS / GPS + and GLONASS signals for positioning.
868MHZ version (S78G)
S76G or S78G expansion board pinout
| ESP32 | Function | Description |
|---|---|---|
| AcSIP S76GX or S78GX GPS receiver | ||
| GPIO33 | TX | UART_GPS_TX |
| GPIO34 | RX | UART_GPS_RX |
| LoRa AcSIP S76GX (868MHz – Europe) or S78GX (433MHz – Asia) modem | ||
| GPIO25 | LCK | SX1276_LCK |
| GPIO26 | BCK | SX1276_BCK |
| GPIO33 | FROM | SX1276_DIN |
| Connector 4-pin , I2C bus | ||
| GPIO21* | I2C | SDA |
| GPIO22* | I2C | SCL |
| MicroSD card reader | ||
| GPIO13 | CS | TF_CS |
| GPIO15 | DAWDLE | TF_MOSI |
| GPIO02 | MISO | TF_MISO |
| GPIO14 | SCLK | TF_SCLK |
The modem is powered by the LDO3 pin
Activating the LoRa modem
Use these keys in the config.h file to enable S7xG modem support
LILYGO_WATCH_HAS_S76_S78G
Useful links
AcSIP S76GXB and S78G technical documentation
Other boards pinout
Here is the pinout of the other expansion boards.
| Expansion board | Pins |
| Microphone | MIC_DATA 34 MIC_CLOCK 26 |
| GamePad | GAMECONTROL_CONTS 5 GAMECONTROL_PINS {13,14,25,26,15} GAMECONTROL_BUZZER 4 |
| MAX98357A + INMP441 | MAX98357A TWATCH_DAC_IIS_BCK 26 INMP441 TWATCH_INMP441_IIS_BCK 15 |
| PN532 | TWATCH_PN532_IRQ 34 TWATCH_PN532_RESET 33 |
| T-Quick 2 motor outputs | TWATCH_TQUICK_EN 2 TWATCH_TQUICK_MA1 26 TWATCH_TQUICK_MA2 25 TWATCH_TQUICK_MB1 13 TWATCH_TQUICK_MB2 15 |
| Carte Lora SX1276 Lora only. Communication via the SPI bus
| TWATCH_LORA_SCK 14 TWATCH_LORA_MISO 2 TWATCH_LORA_MOSI 15 TWATCH_LORA_SS 13 TWATCH_LORA_DI0 26 TWATCH_LORA_RST 25 |
