01 · Meet the board — Desk Dash field guide

Top-down view of the ESP32-S3 Reverse TFT Feather showing the 1.14 inch display, reset button on the left, and D0, D1, D2 buttons on the right — **Display side.** The 1.14″ color TFT dominates the front, flanked by **Reset** (left) and the three user buttons **D0 / D1 / D2** (right). The two rows of holes are the Feather-standard GPIO pins — like everything but the USB-C port, they're unused by this project and free for your next one.

Vital statistics

The 30-second tour

ESP32-S32× cores @ 240 MHz

4 MB + 2 MBFlash + PSRAM

2.4 GHzWi-Fi + BLE 5

240 × 135Color TFT (ST7789)

3 + 1User buttons + reset

USB-CNative USB, no adapter chip

LiPolyCharger + fuel gauge

STEMMA QTPlug-and-play I²C port

The ESP32-S3 is Espressif's Wi-Fi microcontroller — the same family that powers a huge share of the world's smart plugs and IoT gadgets. Two Xtensa cores at 240 MHz and megabytes of RAM is lavish by microcontroller standards, and exactly why it runs Python comfortably (chapter 02).

Naming things

Why “Reverse”? Why “Feather”?

Both sides of the board: display side on the left, component side with the ESP32-S3 module on the right — **Two-faced by design.** Display side (left) and component side (right). All the electronics live on the back so the front is pure screen.

Feather is Adafruit's standard board shape — a shared form-factor spec with a fixed pin layout, so hundreds of boards and stackable “FeatherWing” add-ons are interchangeable, like LEGO for electronics.

A regular TFT Feather puts the screen on the same side as the chips. The Reverse edition flips it to the opposite side, so you can mount the board flat against a case or stand and still face the display — perfect for a desk gadget that's all screen.

Field notes

Subsystems, up close

Everything the dash touches, in hardware form. Captions note the GPIO pins you'll meet again in chapter 03 — all internal board wiring, nothing you connect yourself.

Close-up of the ESP32-S3 module with its metal shield and printed antenna — **The brain.** An ESP32-S3 module: CPU, radio, flash and PSRAM under one metal can, with the Wi-Fi antenna printed on the black overhang at the board's edge.

Close-up of the 1.14 inch color TFT display — **The face.** A 1.14″ IPS TFT, 240×135 pixels, driven by an ST7789 controller over SPI. Its power rail hangs off `GPIO7` and its backlight off `GPIO45` — both must be driven HIGH before you see anything.

Close-up of the D1 and D2 buttons — **Inputs, part 1.** `D1` (GPIO1) and `D2` (GPIO2) are simple push-buttons that read HIGH when pressed. The dash uses them to page between API keys.

Close-up of the D0 boot button — **Inputs, part 2.** `D0` (GPIO0) is wired the opposite way — it reads LOW when pressed — because it doubles as the **BOOT** button that puts the chip into firmware-flashing mode. In the dash it toggles the account overview.

Close-up of the USB-C port and battery connector — **Power.** USB-C for power + programming, plus a JST connector for an optional LiPoly battery with onboard charging and a MAX17048 fuel gauge. USB-C is the *only* connection the dash uses — power, programming, and file transfer all ride that one cable; the battery connector, like every other port, goes unused.

Close-up of the STEMMA QT connector — **Expansion.** The STEMMA QT port chains I²C sensors with a cable — no soldering. Unused by the dash, but a one-plug upgrade path (air quality on your spend monitor, anyone?).

Close-up of the NeoPixel RGB LED — **The blinky bit.** One NeoPixel RGB LED (data `GPIO33`, power gate `GPIO21`) — your “hello, world” in chapter 02.

The board next to a US quarter for scale — **For scale.** 50.8 × 22.8 mm — a full computer with a screen, barely two coins long.

The map

Pinout: reference only — USB-C is the only connection

First, the important part: this project connects to nothing but the USB-C port. Every header pin, pad, and connector on the board goes unused — there is nothing to wire, jumper, or solder. The map below is purely for reference: the display and buttons are wired to GPIOs inside the board, and those numbers surface again in the firmware (chapter 03).

Adafruit's official display-side pinout diagram of the ESP32-S3 Reverse TFT Feather — **Adafruit's official display-side pinout.** The component side has its own diagram — both live in the learn-guide pinouts page.

Every signal in this table is internal board wiring between the ESP32-S3 and the onboard display, buttons, and LED — none of it involves a physical connection on your part.

Signal	GPIO	Why the firmware cares
SPI clock / data (SCK, MOSI)	36 / 35	The display bus — pixels travel here at 40 MHz
TFT CS / DC / RESET	42 / 40 / 41	Display control lines the ST7789 driver toggles
TFT backlight	45	HIGH = screen lit
TFT + I²C power rail	7	Must be HIGH or the display is dead — the classic “blank screen” gotcha
Buttons D0 / D1 / D2	0 / 1 / 2	D0 reads LOW when pressed (it's also BOOT); D1/D2 read HIGH
NeoPixel data / power	33 / 21	Not used by the dash — but used by you, next chapter

Field tip

Two pins on this board are power gates, not signals: GPIO7 (display + STEMMA rail) and GPIO21 (NeoPixel). Adafruit gates these rails so battery projects can cut power to save energy — the price is that you must switch them on in software first.

Go deeper

Bookmark these

Product page (#5691)Specs, price, stock — and more glamour shots Adafruit learn guideThe board's official manual — this chapter in long form Full pinout referenceEvery pin, both sides, annotated — reference only for this project Schematic & CAD filesFor enclosure design or tracing a circuit ESP32-S3 datasheet (PDF)The chip itself, in 700 pages of detail The Feather specWhy this board shape is an ecosystem