An expansion board is a base that a small dev board plugs into, which spreads its pins out into rows that sensor and servo leads push straight onto. This one takes the 18-pin ESP32-S3 SuperMini and gives it 15 colour-coded 3-pin rows, each with signal, power and ground side by side, so a 3-wire sensor or servo lead plugs in without jumper wires or soldering.
Use it for wiring several sensors to one board, running servo signals for a small robot, an ESPHome prototype, or a permanent build that replaces a breadboard full of loose jumpers. It fits the ESP32-S3 SuperMini only, not the ESP32-S3 Zero, and the SuperMini needs its male headers fitted to plug into the sockets (or choose the Soldered SuperMini). The sockets and headers on this board come fitted. The power rows give 3.3V from the module, which suits most sensors, so give servos and motors their own 5V supply and join the grounds. The battery connector is a power input, not a charger, so charge the cell with a separate charger.
Specifications
Datasheets
Wiring & getting started
- Start with nothing connected
No USB, no battery and nothing in the rows. Check the two small links at the top are on the 3V3 side, which is how the board ships.
- Fit the SuperMini the right way round
Turn the SuperMini so its USB-C end faces the battery connector. Its 5V, GND and 3V3 pins then line up with the 3 x 3 power block. Push both rows in evenly and check no pin is left out or sitting one hole off.
- Check the rails (optional)
Plug USB-C into the SuperMini and meter against any black pin. Every red pin should read about 3.3V and the blue power-block pins about 5V.
- Plug in your sensors and servos
Match the lead to the row: yellow to signal, red to VCC, black to GND, and check the sensor runs on 3.3V. For a servo, plug only its signal wire into a yellow pin, run its power wire to a separate 5V supply and join that supply's ground to a black pin. Keep servos off the bottom right row (TX, GPIO43), which sends start-up messages that make a servo twitch.
- Check it works
In your code, use the GPIO number, not the row label: row 3 is GPIO11, not GPIO3. The row test sketch in the Quick Start guide above sets each row high in turn and prints, for example, Row 3 (GPIO11) HIGH every 3 seconds, and that row's yellow pin reads about 3.3V. A row that never goes high usually means a pin is not fully seated. If the SuperMini stays dark or gets warm, unplug at once: it is in the wrong way round or one hole off.
Note: Leave the two VCC links on 3V3 unless you mean to change them. Moved to BAT, a row follows the battery up to about 4.2V, which can damage 3.3V-only sensors.