Lilygo TTGO T8-C3

Overview

Lilygo TTGO T8-C3 is an IoT mini development board based on the Espressif ESP32-C3 WiFi/Bluetooth dual-mode chip.

It features the following integrated components:

• ESP32-C3 chip (160MHz single core, 400KB SRAM, Wi-Fi)

• on board antenna and IPEX connector

• USB-C connector for power and communication

• JST GH 2-pin battery connector

• LED

Lilygo TTGO T8-C3

Functional Description

This board is based on the ESP32-C3 with 4MB of flash, WiFi and BLE support. It has an USB-C port for programming and debugging, integrated battery charging and an on-board antenna. The fitted U.FL external antenna connector can be enabled by moving a 0-ohm resistor.

Connections and IOs

The ttgo_t8c3 board target supports the following hardware features:

Interface	Controller	Driver/Component
PMP	on-chip	arch/riscv
INTMTRX	on-chip	intc_esp32c3
PINMUX	on-chip	pinctrl_esp32
USB UART	on-chip	serial_esp32_usb
GPIO	on-chip	gpio_esp32
UART	on-chip	uart_esp32
I2C	on-chip	i2c_esp32
SPI	on-chip	spi_esp32_spim
TWAI	on-chip	can_esp32_twai

Start Application Development

Before powering up your Lilygo TTGO T8-C3, please make sure that the board is in good condition with no obvious signs of damage.

System requirements

Prerequisites

Espressif HAL requires WiFi and Bluetooth binary blobs in order work. Run the command below to retrieve those files.

west blobs fetch hal_espressif

Note

It is recommended running the command above after west update.

Building & Flashing

Simple boot

The board could be loaded using the single binary image, without 2nd stage bootloader. It is the default option when building the application without additional configuration.

Note

Simple boot does not provide any security features nor OTA updates.

MCUboot bootloader

User may choose to use MCUboot bootloader instead. In that case the bootloader must be built (and flashed) at least once.

There are two options to be used when building an application:

1. Sysbuild

2. Manual build

Note

User can select the MCUboot bootloader by adding the following line to the board default configuration file.

CONFIG_BOOTLOADER_MCUBOOT=y

Sysbuild

The sysbuild makes possible to build and flash all necessary images needed to bootstrap the board with the ESP32-C3 SoC.

To build the sample application using sysbuild use the command:

west build -b ttgo_t8c3 --sysbuild samples/hello_world

By default, the ESP32-C3 sysbuild creates bootloader (MCUboot) and application images. But it can be configured to create other kind of images.

Build directory structure created by sysbuild is different from traditional Zephyr build. Output is structured by the domain subdirectories:

build/
├── hello_world
│   └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
├── mcuboot
│    └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
└── domains.yaml

Note

With --sysbuild option the bootloader will be re-build and re-flash every time the pristine build is used.

For more information about the system build please read the Sysbuild (System build) documentation.

Manual build

During the development cycle, it is intended to build & flash as quickly possible. For that reason, images can be built one at a time using traditional build.

The instructions following are relevant for both manual build and sysbuild. The only difference is the structure of the build directory.

Note

Remember that bootloader (MCUboot) needs to be flash at least once.

Build and flash applications as usual (see Building an Application and Run an Application for more details).

# From the root of the zephyr repository
west build -b ttgo_t8c3 samples/hello_world

The usual flash target will work with the ttgo_t8c3 board target. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b ttgo_t8c3 samples/hello_world
west flash

The default baud rate for the Lilygo TTGO T8-C3 is set to 1500000bps. If experiencing issues when flashing, try using different values by using --esp-baud-rate <BAUD> option during west flash (e.g. west flash --esp-baud-rate 115200).

You can also open the serial monitor using the following command:

west espressif monitor

After the board has automatically reset and booted, you should see the following message in the monitor:

***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
Hello World! ttgo_t8c3

Sample applications

The following samples will run out of the box on the TTGO T8-C3 board.

To build the blinky sample:

# From the root of the zephyr repository
west build -b ttgo_t8c3 samples/basic/blinky

To build the bluetooth beacon sample:

# From the root of the zephyr repository
west build -b ttgo_t8c3 samples/bluetooth/beacon

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