The Cardputer is a small ESP32 based device with Wifi, Bluetooth, battery and keyboard. Dualcore 240Mhz cpu is quite something, it also has a MMU, but the 512kb of RAM are not enough for NetBSD or Linux.
I got the device to play with Meshtastic/MeshCore, details here. Yet to be tested is my other use case: for FT8 transmissions, when connected to my QMX+ radio transmitter.
My hardware is the “M5Stack Cardputer” together with the LoRa1262 extension, for ~9000円/55USD. Small disappointment: the antenna is built for 868Mhz: I can use it on the 930Mhz area used for LoRa here in Japan, can do communication to nearby devices which use a proper 930Mhz antenna - but the LoRa1262 extension’s antenna won’t radiate well enough for far communications.
First things
The Cardputer has 8mb flash. Connecting via USB-C to Linux, you can install
“M5Launcher” and from then on that launcher is executed after each start.
Pressing return enters the launcher, and allows to flash software via Wifi
from the internet, or from files on the MicroSD card. Without pressing
return, the currently flashed software is started.
Here is a catalog of the software, plus some projects not listed there. Notable software/use cases:
- Meshtastic/MeshCore
- ‘fat’ applications which list wlans, do network sniffing, and so on. Reminds of the “Flipper Zero”, just that the Cardputer has no RFID/ NFC build in.
- Badapple and Doom, of course :)
- A few games, emulators for NES etc.
- MP3 player, webradio
- Software which allows the Cardputer, connected via USB-C to an other system, to behave like a normal USB-keyboard or mouse
- The LoRa1262 extension has also GPS etc, so software to read that
Antenna connector
Trying to connect a 930Mhz antenna, I noticed: the connector on the LoRa1262 extension is not normal SMA: this turns out as RP-SMA, RP meaning “reversed polarity” of the physical connector. Stores in Akihabara were not able to identify this - but once you know this is RP-SMA, you can order a gender changer/adapter online.
Meshtastic
The catalog has quite some Meshtastic software, I tried:
- Meshtastic For Cardputer-Adv (ozbk): I mostly used this so far, no issues.
- Meshtastic for Cardputer ADV with Cap Lora (Gt4kill3r) is right now based on a slightly newer upstream Meshtastic software, 2.7.23
- Cardputer Mesh Kit Meshtastic Firmware (M5Stack) is based on upstream version 2.7.22
- Plai (d4rkmen), upstream, as of 2026/5/6 in version 2.1.
I played with all of these - they are interoperable, also Plai is sending/receiving normal Meshtastic, apparently with an own implementation. The first 3 here are based on upstream Meshtastic, no big differences seen apart from changes coming in from upstream.
Plai is much more shiny and polished, but has a big downside for me: after flashing the Meshtastic based variants, I can open https://client.meshtastic.org/ in Chromium and conveniently configure all settings. Plai is not offering that API, it’s really to be used on the Cardputer only.
Europe settled on 868Mhz LoRa frequencies, Japan with 930Mhz. After handing out one of the 868Mhz antennas to a friend in error, I measured my antennas with a NanoVNA and am now wrapping each antenna with a label: blue is for 868/Europe range.
MeshCore
Already Meshtastic is rare to see here in Tokyo, even less MeshCore, so I have no longterm experiences with the MeshCore implementations.
For configuration, many Cardputer MeshCore firmwares come without a profile for Japan, so it’s important to manually configure for 920.6Mhz, 62.5, 8, 8, 20mW. Source.
- MeshCore-Cardputer-ADV M5Stack Cap LoRa1262 version!!!! (Stachu0) As of 2026/5/6 in version v1.1.0
- MeshClient for CardPuter & ADV (whywilson) has as of 2026/05 no support for the Lora extension I have
- MeshCore (przemeks), upstream As of 2026/5, version v1.14.1.74
Looking forward to get a 930Mhz antenna for the Cardputer.. and to trying out FT8 with the radio transceiver. There is now a page on the Wiki for the Cardputer.
Corrections? Questions? -> Fediverse thread