You basically can’t run a real JVM on an [Arduino Nano](https://www.ampheo.com/product/a000005-25542476) – the board is just far too small for it.

Let’s unpack that and then I’ll show you what is realistic.


**1. Why JVM on Nano is (basically) impossible**

**Classic Arduino Nano hardware:**

* MCU: [ATmega328P](https://www.ampheo.com/search/ATmega328P), 8-bit, 16 MHz
* 2 KB RAM
* 32 KB flash (and some of that is used by the bootloader)

A normal Java Virtual Machine (JVM) expects:

* Hundreds of KB to MBs of RAM (for heap, stack, GC, class metadata…)
* Much more flash/storage for the VM itself + your classes
* Often an OS layer underneath (or at least a pretty beefy runtime)

Even “tiny” embedded JVMs are designed for 32-bit MCUs with far more RAM and flash, or full SoCs like Raspberry Pi. An ATmega328P simply doesn’t have the resources.

So:

No standard JVM (HotSpot, OpenJDK, etc.) can run on an Arduino Nano.
Even special micro-VMs for Java are not practical on the Nano for real projects.

**2. What about tiny Java VMs / experimental stuff?**

There have been research/educational projects like NanoVM, Darjeeling VM, etc., that run a very restricted Java subset on small [microcontrollers](https://www.ampheo.com/c/microcontrollers).

But:

* They require replacing the Arduino firmware completely with their own VM.
* You lose the normal Arduino ecosystem (IDE libraries, typical sketches).
* Supported [MCUs/boards](https://www.onzuu.com/category/embedded-mcu-dsp-evaluation-boards) are old, niche, and the ecosystem is basically dead.
* You still only get a very tiny Java subset, not a full JVM experience.

For modern, practical work, these are more “historical curiosities” than usable solutions.

**3. The practical architecture: Java on a host, Nano as I/O**

The realistic and nice way to combine Java/JVM and Arduino Nano:

**1. Arduino Nano**

* Runs normal C/C++ firmware (Arduino sketches).
* Handles [sensors](https://www.ampheo.com/c/sensors), [actuators](https://www.onzuu.com/category/electric-actuators-cylinders), GPIO, timing, etc.
* Communicates via Serial (USB), I²C, SPI, etc.

**2. JVM device (PC / laptop / Raspberry Pi / Android)**

* Runs your Java (or Kotlin, Scala, etc.) program.
* Opens a serial port (or Bluetooth/Wi-Fi link) to talk to the Nano.
* Sends commands like SET_LED 1, GET_TEMP, etc., and parses responses.

This way:

* You keep the ease of Java/JVM for logic, GUI, networking, databases…
* You let the [microcontroller](https://www.ampheoelec.de/c/microcontrollers) do what it’s good at: real-time I/O, low-level hardware.