M5Stamp S3 WiFi and BLE IoT module offers up to 23 GPIOs through 2.54mm and 1.27mm pitch holes

M5Stamp S3, aka M5Stamp ESP32S2 or Stamp S3, is a tiny ESP32-S3 WiFi & Bluetooth LE (BLE) IoT module with a USB Type-C port, over 20 I/Os available through 2.54mm and 1.27mm pitch headers and castellated holes, and a heat-resistant cover.

Many of the “new” ESP32-S3 hardware platforms launches these days are often updates from an ESP32 design, and the M5Stack’s M5Stamp S3 is no exception building on the original M5Stamp Pico, and its ESP32-C3 variants, namely M5Stamp C3 and C3U.

M5Stamp S3 specifications:

WiSoC – Espressif Systems ESP32-S3FN8 dual-core 32-bit Xtensa LX7 microcontroller with AI vector instructions up to 240MHz, RISC-V ULP co-processor, 512KB SRAM, 2.4GHz WiFi 4 (802.11b/g/n), Bluetooth 5.0 BLE + Mesh, 8MB flash as found in the M5Stack ATOMS3 (Lite).
Connectivity
- 2.4 GHz WiFi 4, 20 MHz and 40 MHz bandwidth, IEEE 802.11 b/g/n protocol, up to 150 Mbps
- Bluetooth 5, Bluetooth Mesh, with supports for 125 Kbps, 500 Kbps, 1 Mbps, 2 Mbps bitrate, long range support
- 2.4GHz 3D antenna
USB – 1x USB Type-C port for power and programming
Expansion
- 2.54mm and 1.27mm pitch headers and castellated holes with
  - Up to 23x GPIOs
  - SD/SDIO/MMC
  - Touch sensor
  - SPI master/slave
  - EMAC
  - Motor PWM, LED PWM
  - UART, I2C, I2S, pulse counter
- Optional 8-pin or 12-pin FPC connector with GPIO, LCD interface
Misc – 1x user button, 1x user RGB LED (WS2812B-2020)
Power Supply
- Input – 5V @ 500mA via USB-C port
- MUN3CAD01-SC 5V to 3.3V DC/DC converter
Dimensions – 26 x 18 x 5mm
Weight – 3.2 grams
Temperature Range – 0 to 40°C

M5Stamp S3 pinout diagram — Pinout diagram

The board can be programmed with Arduino or the company’s UIFlow online IDE, and let’s hope they have put more effort into the latter, as the documentation only links to an RGB LED blink sample. Target applications include Smart Home appliances, wearables, and medical equipment. The heat-resistant plastic protects the main components and the 3D antenna and can be installed before soldering onto or inserting the module into the customer’s board.

The main advantage of using ESP32-S3 over ESP32-C3 are the vector instructions for machine learning, having two cores, a little bit more SRAM, and a greater number of I/Os. It’s difficult to benefit from the extra GPIOs on such a small module, so instead of just providing 2.54mm pitch headers, M5Stack added some 1.27mm pitch through holes with most I/Os also offered through castellated holes to enable SMT soldering. They also added some pads to solder an FPC connector.

M5Stack is selling the M5Stamp S3 for $7.5 plus shipping.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.