the boxes

Which box is which

Everything on this site runs on a device you buy finished, in a shop. Here the devices stand side by side: what each one is, what runs on it today, what it costs and what it cannot do.

M5Stack Core2, works today

ESP32-D0WDQ6-V3 · original series

A palm-sized square box with a screen, a speaker and a battery inside. It comes finished: no assembly, nothing to solder.

Runs on it: Open Radio works today · RADBOX in testing.

What it cannot do: run both systems at once — installing RADBOX replaces the radio, and the other way round.

Price: €50 (checked 31 Jul 2026)

Where to buy

Botland (Poland) ↗M5Stack ↗

Paid partnership. When you buy through the link to the M5Stack shop, the shop pays me a commission. Botland gives me devices for testing, but I get nothing when you buy there. Buy the box anywhere you like; the system works the same.

M5Stack Unit C6L, works today

ESP32-C6 · C series

A small white radio as wide as a coin, with two antennas and a tiny status display; your phone is the real screen.

Runs on it: Biper works today. One system, for messages where there is no phone signal.

What it cannot do: run on its own battery — there is none inside; it runs from USB or a power bank.

Price: see the project page; you need two

ZECTRIX NOTE4C, works today

ESP32-S3 · S series

A device just under 10 × 10 cm with a 4.2-inch electronic-paper screen, three buttons and a stand. Once it has drawn a picture, it holds it without power.

Runs on it: emini Home works today. One system, with its own website.

What it cannot do: show anything that moves — a full redraw takes more than ten seconds.

Price: see the project page

M5Stack Tab5, no system yet

ESP32-P4 · P series

A five-inch touchscreen with the fastest chip on this page, a camera and a full-size USB socket. The battery is a camera battery you buy separately.

Runs on it: nothing you can install yet.

What it cannot do: send sound over Bluetooth.

Price: €65, battery extra (checked 22 Aug 2026)

Side by side

Only what changes the decision. The rest is on the pages linked above.

On a phone the table scrolls sideways →

Side by side
Feature	M5Stack Core2	M5Stack Unit C6L	ZECTRIX NOTE4C	M5Stack Tab5
Screen	2-inch, 320 × 240 pixels touch	a tiny status display the phone is the real screen	4.2-inch e-paper, 400 × 300 pixels black, white, red and yellow	5-inch, 1280 × 720 pixels touch
Power	built-in battery, 500 mAh about 2.5 hours of radio without a cable	no battery inside USB or a power bank	built-in battery the screen needs no power to hold a picture; the device still needs regular charging	battery sold separately a camera battery, type NP-F550
Wireless	Wi-Fi 2.4 GHz + Bluetooth can also play through a Bluetooth speaker	LoRa 868 MHz + Wi-Fi 2.4 GHz (Wi-Fi 6) the chip has Bluetooth, but the system keeps it off; no SIM, no subscription; 868 MHz is licence-free in Europe	Wi-Fi 2.4 GHz the chip has Bluetooth, but the system keeps it off	Wi-Fi 2.4 GHz (Wi-Fi 6) + Bluetooth both from a second chip, an ESP32-C6; no sound over Bluetooth
Sound	built-in speaker	a buzzer	—	built-in speaker + headphone socket for a Bluetooth speaker, plug a small Bluetooth transmitter into the headphone socket

What now

Two ways in, depending on where you are starting from.

I have never installed anything See what runs on these