M5Stack Stamp-C5, also known as the M5Stamp-C5, is a tiny wireless IoT USB-C board based on the Espressif ESP32-C5 RISC-V microcontroller with dual-band WiFi 6, Bluetooth LE, and 802.15.4 (Zigbee/Thread) connectivity.
Despite its small size (19.1 x 17.6mm), the module exposes up to nineteen GPIO pins, eleven on standard 2.54mm pitch headers and castellated holes, and eight on an FPC extension connector. The board also supports battery charging and ships with an external IPEX antenna for wireless connectivity, since there’s no built-in antenna.
M5Stack Stamp-C5 specifications:
- Wireless MCU – Espressif Systems ESP32-C5HF4
- CPU
- Single-core 32-bit RISC-V processor @ up to 240 MHz
- Low-power RISC-V core @ 48 MHz acting as the main processor for power-sensitive applications
- Memory – 384 KB SRAM on-chip
- Storage – 320 KB ROM, 4MB SPI flash
- Wireless
- Dual-band (2.4/5 GHz) 802.11ax WiFi 6, 802.11b/g/n WiFi 4 backward compatibility
- WiFi modes: Station mode, SoftAP mode, SoftAP + Station mode, and promiscuous mode
- Bluetooth 5.0 Low Energy (LE) with Mesh support, up to 2Mbps data rate
- 802.15.4 radio for Zigbee 3.0, Thread 1.3, and Matter up to 250 Kbps
- CPU
- Antenna – IPEX-1 antenna connector with LFD182G45DCHD481 dual-band diplexer for 2.4/5 GHz selection
- USB
- USB Type-C port for power and programming
- D+/D- pads on the bottom of the board
- Expansion
- 2x 7-pin headers (through holes and castellated holes) with up to 11x GPIO, 5V (VUSB), 3.3V, VBAT, and GND
- 12-pin FPC connector with up to 8x GPIO, UART, 3.3V, GND
- Misc
- Charging and Boot/User (G28) LEDs
- Tx/Rx pads for debugging
- Boot and Reset pads
- Power Supply
- 5V via USB Type-C port
- 3.7V battery support via SGM40567-4.2XG/TR charging IC; Approx. 200mA charging current
- Consumption – Deep sleep: 3.7V @ 13uA
- Dimensions – 19.1 x 17.6 x 3.4mm
- Weight – 1.8 grams or 2.4 grams with headers
Two versions of the board are available: the Stamp-C5 as shown above, and the Stamp-C5 DIP with the 12-pin FPC connector soldered on, and two 7-pin headers (not soldered). M5Stack provides PDF schematics, a pinout diagram (see below), and instructions for getting started with the Arduino IDE on the documentation website.
The Stamp-C5 is the smallest ESP32-C5 USB-C IoT board/module we’ve seen so far, with the two closest competitors being the XIAO ESP32-C5 (21 x 17.8mm) with an ESP32-C5HR8 chip (8MB PSRAM) and an 8MB SPI flash) and the NiceMCU ESP32-C5 Mini (27.9 x 17.8 mm) based on the same ESP32-C5HF4, but with on-board antenna and IPEX connector, and no battery support. The Stamp-C5 offers more I/Os than either thanks to its extra FPC connector.
The company sells the Stamp-C5 for $6.50, and the DIP variant for $7.95 on the M5Stack store, and both should soon become available on the M5Stack AliExpress store.
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.
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