Gemma vs Circuit Playground vs ESP32: Which Board is Right for Your Project?
Choosing a microcontroller is easier when you start with what your project actually needs. The compact Adafruit Gemma M0, feature-packed Circuit Playground Express, and wireless ESP32 development board can all power creative electronics, but each suits a different kind of build.
Gemma vs Circuit Playground vs ESP32 at a glance
| Feature | Gemma M0 | Circuit Playground Express | ESP32 development board |
|---|---|---|---|
| Board size | Very small, round, and easy to hide in a wearable | Larger round board with room for built-in components | Rectangular breadboard-style board |
| Battery connection and charging | JST battery connector; no onboard charging | JST battery connector; no onboard charging | No onboard battery connector or charging on this standard board; use suitable external power hardware |
| Wireless features | None | None on the Express model | Wi-Fi and Bluetooth built in |
| Capacitive touch | All three I/O pads can be used as capacitive-touch inputs | Seven large pads, A1–A7, support capacitive touch | Up to ten hardware touch channels on the classic ESP32 chip; use touch-capable GPIOs exposed by the board |
| Programming environments | CircuitPython and Arduino IDE | MakeCode, CircuitPython, and Arduino IDE | Arduino IDE, MicroPython, and ESP-IDF |
| Pin availability | Three large sewable I/O pads, plus power and ground | Multiple large connection pads plus built-in sensors, buttons, sound, and LEDs | Many GPIO pins for sensors, displays, and add-ons; capabilities vary by pin |
| Beginner fit | Excellent for a small first wearable | Best all-round choice for learning and workshops | Best after the basics, or when wireless is essential |
| Best for | Compact sewn wearables and simple touch-controlled light projects | Interactive beginner projects and experimentation | Connected projects, data, and larger builds |
Choose Gemma M0 for a small wearable
The Gemma M0 is the smallest and easiest of these boards to tuck into a costume, bag, or accessory. Its large pads can be connected with conductive thread or alligator clips, and CircuitPython makes it approachable for beginners.
Touch sensing: All three I/O pads can act as capacitive-touch inputs. Connect conductive fabric, conductive thread, foil, or another conductive surface to make soft buttons and touch controls without adding a separate touch sensor.
The trade-off is expansion: the same three pads used for touch are also the available general-purpose inputs and outputs, so they fill up quickly. Gemma has a JST connector for compatible battery power, but it does not charge the battery onboard. Recharge a rechargeable battery only with a separate charger designed for that battery.
Best choice when: size and sewability matter more than wireless connectivity or a large number of pins.
Choose Circuit Playground Express for learning
The Circuit Playground Express gives beginners useful parts right on the board, including ten NeoPixels, buttons, motion sensing, temperature and light sensing, and sound features. That means fewer extra components before you can make something interesting.
Touch sensing: Seven of its large outer pads, A1 through A7, can act as capacitive-touch inputs. The big pads are easy to clip onto while prototyping and easy to connect to conductive fabric or thread for sewn controls. MakeCode also makes touch-triggered projects especially approachable.
It supports visual MakeCode programming as well as CircuitPython and Arduino, so it can grow with the maker. Like Gemma, it accepts compatible battery power through a JST connector but does not provide onboard battery charging.
Best choice when: you want the gentlest learning curve, are teaching a class, or want to experiment before buying separate sensors and LEDs.
Choose ESP32 when the project needs wireless
The ESP32 development board is the clear choice when a project needs Wi-Fi, Bluetooth, or many connections. It can collect sensor data, communicate with online services, control displays, and handle more complex builds.
Touch sensing: The classic ESP32 chip provides up to ten hardware capacitive-touch channels. Touch must be connected to a touch-capable GPIO that is actually broken out on the development board. Check the specific board pinout before wiring, because not every GPIO supports touch and exposed pins vary between ESP32 models.
The standard board is less wearable-friendly than Gemma or Circuit Playground. It uses header pins rather than large sewable pads, and its power setup needs more planning. For clothing and soft-circuit projects, the Beetle ESP32 Microcontroller [Sewable] offers ESP32 connectivity in an integration-friendly format. For a guided touch-and-wireless project, try the ESP32 Connecting Kit: Touch Wearable with Live Weather Data.
Best choice when: wireless connectivity, multiple touch inputs, or lots of pins is central to the idea.
Which programming environment should you use?
- MakeCode: The easiest visual starting point, available for Circuit Playground Express.
- CircuitPython: A friendly text-based next step for Gemma M0 and Circuit Playground Express, with touch input available through its touch libraries.
- Arduino IDE: Supported across all three choices and backed by a huge library of examples.
- MicroPython or ESP-IDF: Useful ESP32 options for makers who want more control.
Which board should you buy?
- Pick Gemma M0 for the smallest, simplest sewn wearable or a few soft touch controls.
- Pick Circuit Playground Express for the easiest all-round beginner experience and seven easy-to-connect touch pads.
- Pick an ESP32 development board when Wi-Fi, Bluetooth, multiple touch channels, or lots of connections matter most.
If you are new to soft circuits, read our complete beginner’s guide to wearable electronics for project planning, materials, circuit basics, and first-build tips.