Adafruit Feather ESP32S3 TFT

Overview

The Adafruit Feather ESP32-S3 TFT is an ESP32-S3 development board in the Feather standard layout, sharing peripheral placement with other devices labeled as Feathers or FeatherWings. The board is equipped with an ESP32-S3 mini module, a LiPo battery charger, a fuel gauge, a USB-C and Qwiic/STEMMA-QT connector. Compared to the base model, this TFT variant additionally comes with a 240x135 pixel IPS TFT color display. For more information, check Adafruit Feather ESP32-S3 TFT [5].

Hardware

  • ESP32-S3 mini module, featuring the dual core 32-bit Xtensa Microprocessor (Tensilica LX7), running at up to 240MHz

  • 512KB SRAM and either 4MB flash + 2MB PSRAM

  • USB-C directly connected to the ESP32-S3 for USB/UART and JTAG debugging

  • LiPo connector and built-in battery charging when powered via USB-C

  • MAX17048 fuel gauge for battery voltage and state-of-charge reporting

  • Charging indicator LED, user LED, reset and boot buttons

  • Built-in NeoPixel indicator RGB LED

  • STEMMA QT connector for I2C devices, with switchable power for low-power mode

  • 240x135 pixel IPS TFT color display with 1.14” diagonal and ST7789 chipset

ESP32-S3 Features

ESP32-S3 is a low-power MCU-based system on a chip (SoC) with integrated 2.4 GHz Wi-Fi and Bluetooth® Low Energy (Bluetooth LE). It consists of high-performance dual-core microprocessor (Xtensa® 32-bit LX7), a low power coprocessor, a Wi-Fi baseband, a Bluetooth LE baseband, RF module, and numerous peripherals.

ESP32-S3 SoC includes the following features:

  • Dual core 32-bit Xtensa Microprocessor (Tensilica LX7), running up to 240MHz

  • Additional vector instructions support for AI acceleration

  • 512KB of SRAM

  • 384KB of ROM

  • Wi-Fi 802.11b/g/n

  • Bluetooth LE 5.0 with long-range support and up to 2Mbps data rate

Digital interfaces:

  • 45 programmable GPIOs

  • 4x SPI

  • 1x LCD interface (8-bit ~16-bit parallel RGB, I8080 and MOTO6800), supporting conversion between RGB565, YUV422, YUV420 and YUV411

  • 1x DVP 8-bit ~16-bit camera interface

  • 3x UART

  • 2x I2C

  • 2x I2S

  • 1x RMT (TX/RX)

  • 1x pulse counter

  • LED PWM controller, up to 8 channels

  • 1x full-speed USB OTG

  • 1x USB Serial/JTAG controller

  • 2x MCPWM

  • 1x SDIO host controller with 2 slots

  • General DMA controller (GDMA), with 5 transmit channels and 5 receive channels

  • 1x TWAI® controller, compatible with ISO 11898-1 (CAN Specification 2.0)

  • Addressable RGB LED, driven by GPIO38.

Analog interfaces:

  • 2x 12-bit SAR ADCs, up to 20 channels

  • 1x temperature sensor

  • 14x touch sensing IOs

Timers:

  • 4x 54-bit general-purpose timers

  • 1x 52-bit system timer

  • 3x watchdog timers

Low Power:

  • Power Management Unit with five power modes

  • Ultra-Low-Power (ULP) coprocessors: ULP-RISC-V and ULP-FSM

Security:

  • Secure boot

  • Flash encryption

  • 4-Kbit OTP, up to 1792 bits for users

  • Cryptographic hardware acceleration: (AES-128/256, Hash, RSA, RNG, HMAC, Digital signature)

Asymmetric Multiprocessing (AMP)

Boards featuring the ESP32-S3 SoC allows 2 different applications to be executed. Due to its dual-core architecture, each core can be enabled to execute customized tasks in stand-alone mode and/or exchanging data over OpenAMP framework. See Inter-Processor Communication (IPC) folder as code reference.

For more information, check the ESP32-S3 Datasheet [1] or the ESP32-S3 Technical Reference Manual [2].

Supported Features

The current adafruit_feather_esp32s3_tft board supports the following hardware features:

Interface

Controller

Driver/Component

UART

on-chip

serial port

GPIO

on-chip

gpio

PINMUX

on-chip

pinmux

USB-JTAG

on-chip

hardware interface

SPI Master

on-chip

spi

TWAI/CAN

on-chip

can

ADC

on-chip

adc

Timers

on-chip

counter

Watchdog

on-chip

watchdog

TRNG

on-chip

entropy

LEDC

on-chip

pwm

MCPWM

on-chip

pwm

PCNT

on-chip

qdec

GDMA

on-chip

dma

USB-CDC

on-chip

serial

Wi-Fi

on-chip

Bluetooth

on-chip

Connections and IOs

The Adafruit Feather ESP32-S3 TFT User Guide [6] has detailed information about the board including pinouts [7] and the schematic [8].

System Requirements

Binary Blobs

Espressif HAL requires RF 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.

Programming and Debugging

The adafruit_feather_esp32s3_tft board supports the runners and associated west commands listed below.

flash debug attach debugserver rtt
esp32 ✅ (default)
openocd ✅ ✅ (default) ✅ ✅ ✅

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 SoC.

To build the sample application using sysbuild use the command:

west build -b <board> --sysbuild samples/hello_world

By default, the ESP32 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 <board> samples/hello_world

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

# From the root of the zephyr repository
west build -b <board> samples/hello_world
west flash

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! <board>

Board variants using Snippets

ESP32 boards can be assembled with different modules using multiple combinations of SPI flash sizes, PSRAM sizes and PSRAM modes. The snippets under snippets/espressif provide a modular way to apply these variations at build time without duplicating board definitions.

The following snippet-based variants are supported:

Snippet name

Description

Flash memory size

flash-4M

Board with 4MB of flash

flash-8M

Board with 8MB of flash

flash-16M

Board with 16MB of flash

flash-32M

Board with 32MB of flash

PSRAM memory size

psram-2M

Board with 2MB of PSRAM

psram-4M

Board with 4MB of PSRAM

psram-8M

Board with 8MB of PSRAM

PSRAM utilization

psram-reloc

Relocate flash to PSRAM

psram-wifi

Wi-Fi buffers in PSRAM

To apply a board variant, use the -S flag with west build:

west build -b <board> -S flash-32M -S psram-4M samples/hello_world

Note

These snippets are applicable to boards with compatible hardware support for the selected flash/PSRAM configuration.

  • If no FLASH snippet is used, the board default flash size will be used.

  • If no PSRAM snippet is used, the board default psram size will be used.

Debugging

OpenOCD

As with much custom hardware, the ESP32 modules require patches to OpenOCD that are not upstreamed yet. Espressif maintains their own fork of the project. The custom OpenOCD can be obtained at OpenOCD for ESP32 [3].

The Zephyr SDK uses a bundled version of OpenOCD by default. You can overwrite that behavior by adding the -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts> parameter when building.

Further documentation can be obtained from the SoC vendor in JTAG debugging for ESP32 [4].

Here is an example for building the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world -- -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>
west flash

You can debug an application in the usual way. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world
west debug

References