M5Stack has rolled out the Cardputer Mesh Kit, a card-sized off-grid messenger that pairs the company's existing Cardputer-Adv controller with a new LoRa and GNSS expansion called the CapLoRa-1262. The combo ships pre-flashed with Meshtastic firmware, turning the keyboard-equipped handheld into a self-contained node for text messaging and location sharing without cellular service.
The base unit is built around an M5Stamp S3A module with an Espressif ESP32-S3 running a dual-core Xtensa LX7 at 240MHz, alongside 512KB of SRAM and 8MB of flash. It carries a 1.14-inch 240x135 IPS LCD driven by an ST7789V2, a 56-key matrix keyboard with a lighter 160 gf actuation force (down from 260 gf), a microSD slot, a BMI270 motion sensor, a 1W speaker with NS4150B amp, a MEMS microphone, a 3.5mm jack, and an IR transmitter. A 1750mAh Li-ion battery handles power, charged over USB-C through the Stamp module, and the chassis keeps the original Cardputer's magnetic back, lanyard hole, and LEGO-compatible mounting holes.
The CapLoRa-1262 expansion is where the Meshtastic story takes shape. It packs a Semtech SX1262 transceiver covering 868MHz to 923MHz with up to +22 dBm transmit power and -147 dBm sensitivity in low data rate mode, fed by an external SMA rubber-duck antenna. An ATGM336H-6N module based on the AT6668 chipset adds multi-constellation GNSS support for GPS, BeiDou, GLONASS, Galileo, and QZSS, with sub-1.5m CEP50 accuracy via a built-in ceramic antenna. The two boards stack into a combined footprint of 84 x 54 x 34.8mm (3.3 x 2.1 x 1.4 inches) and connect through a 14-pin 2.54mm expansion bus, with a Grove I2C port exposed on each half.
Because the kit lives in the M5Stack ecosystem, the firmware story is wide open. Buyers can stick with the bundled Meshtastic build (flashable straight from a browser via the Meshtastic Web Flasher) or switch to custom code through the Arduino IDE, ESP-IDF, or M5Stack's UiFlow2, with first-party libraries provided for RadioLib and TinyGPSPlus. That puts it in the same conversation as other ESP32-S3 mesh handhelds like the LILYGO T-Deck Pro and T-LoRa Pager, with the Cardputer's tactile keyboard as the differentiator.
The full Cardputer Mesh Kit is shipping now at $48 (€44), bundled with the Cardputer-Adv, the CapLoRa-1262 module, the antenna, and the M2 screws needed to assemble the sandwich. Owners of the existing Cardputer-Adv can grab the CapLoRa-1262 add-on on its own for $14.50 (€13). Schematics and full hardware documentation are posted on the M5Stack docs site.
