M5Stack Cardputer - A $30 card-sized ESP32-S3 computer with display and keyboard

M5Stack Cardputer is a card-sized portable computer based on the ESP32-S3-powered M5Stamp S3 wireless module and equipped with a 56-key keyboard and 1.14-inch TFT display, plus some sensors and peripheral expansion ports.

At first, it’s hard to imagine what it could be used for apart from being a hardware hacking toy, but the company says the card-sized WiFi computer can be used for rapid functional verification, industrial control, and home automation systems.

M5Stack Cardputer specifications:

Wireless MCU module – M5Stack M5Stamp S3 with
- SoC – 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
- 2.4GHz 3D antenna
- USB – 1x USB Type-C port
- Expansion connectors for I/Os such as SPI, I2C, UART, ADC, and more
Storage – MicroSD card socket
Display – 1.14-inch IPS LCD with 240×135 resolution using ST7789V2 driver
Audio – 1W speaker (NS4148) and built-in PDM microphone (SPM1423)
User input – 56-key keyboard (4x 14-key matrix)
Expansion – Grove connector with I2C (5V)
Misc
- Reset button, user button
- On/Off switch
- IR transmitter
- Built-in magnet used for mounting, e.g. attached to a fridge or whiteboard
- Compatible with LEGO hole extensions
Power Supply
- 1,400 mAh battery + 120 mAh battery
- Built-in battery charging and voltage regulation
- Charging via USB-C port on M5Stamp S3 module
Power Consumption
- Standby current – 0.26 uA @ 4.2V
- Operating current
  - Key mode – 165.7 mA @ 4.2V
  - IR mode – 255.6 mA @ 4.2V
Dimensions – 84 x 54 x 17mm
Weight – 92.8 grams

Now that we’ve gone through the detailed specifications more potential projects come to mind such as a Bluetooth keyboard, an automation system using the infrared transmitter to control devices such as TVs or air conditioners within the same room, a portable chat device (although the display is rather small…), an audio recording device, a portable music player, and so on.

The Cardputer only ships with a hex key to open it if needed. M5Stack provides a demo program using the ESP-IDF as well as an Arduino library with some basic examples for the user button, the speaker/buzzer, the display, the IR transmitter, the keyboard, and the microphone. Further technical details can be found in the documentation.

M5Stack are selling the Cardputer for $29.99 plus shipping on their own store.

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.