Guide · Agent skill

How to use the Cardputer Buddy Dev Loop agent skill

Updated 2026-10-29 · written with AI from the project's own documentation and checked against our catalogue data

The cardputer-buddy skill teaches an AI agent how to iterate on a small MicroPython app bundle for the M5 Cardputer-Adv, a handheld device with a keyboard and screen. It is for people who have already set up their device with the m5-onboard skill and want to add or change apps. After reading this guide you will know how to install the skill, how to ask for work in plain language, and which helper scripts the agent uses.

Cardputer Buddy Dev Loopanthropics/claude-plugins-official · Apache-2.0 Download the skill

Quick start

1Download the skill ZIP. Get the cardputer-buddy ZIP from the page where you found this guide.
2Install the skill. Unzip it into ~/.claude/skills/ for personal use, or into a project's .claude/skills/ folder, or upload the ZIP under Settings, Capabilities, Skills in the Claude apps.
3Provision the device first. Run the m5-onboard skill so the Cardputer-Adv is set up and detect.py reports its port.
4Make sure the buddy/ directory is available. Work inside the buddy/ directory of your local build-with-claude clone.
5Ask for the change in plain language. Say something like add an app or push to the cardputer, and include the port if you have it.
6Push and watch. Let the agent push only the changed files and tail the device logs to check the result.

What the cardputer-buddy skill makes the agent do

Agent skills are instruction packs that give an AI agent specific know-how for a task. This one covers the follow-up work after a Cardputer-Adv is already provisioned. The agent can add a new app, such as a menu game or a Claude Buddy client, copy only the files you changed onto the device over USB, watch the device's serial log output, or run a single command on the device.

The skill also documents where files live on the device, so the agent knows which folder each piece belongs in.

Add a new app to the device menu without re-flashing
Push a single changed .py file to the device
Watch device serial logs while the app runs
Run one-shot REPL commands on the device

How to install the cardputer-buddy skill

Download the skill ZIP from the page where you found this guide, then unzip it into one of two places. For a personal setup, put the unzipped folder in ~/.claude/skills/. For a single project, put it in that project's .claude/skills/ folder.

You can also upload the ZIP in the Claude apps. Open Settings, go to Capabilities, then choose Skills and upload the file.

Start a new session after installing so the agent picks up the skill.

Personal install: ~/.claude/skills/
Project install: the project's .claude/skills/ folder
Claude apps: Settings, then Capabilities, then Skills, then upload the ZIP

What you need before the skill can help

The skill assumes the device is already set up. First-time setup is handled by the m5-onboard skill, which runs detect.py to find the device's serial port. If you have not done that yet, run m5-onboard first.

You also need the buddy/ directory from a local build-with-claude clone. The agent works inside that clone, because the buddy/ directory is the MicroPython payload that m5-onboard installs onto the device.

Python 3 on your computer
A Cardputer-Adv connected to your computer over USB-serial
The buddy/ directory from your local build-with-claude clone
Prior provisioning with m5-onboard, which detects the port

Trigger the skill with natural requests

You do not need special syntax. Describe what you want and the agent should pick up the skill when your request matches its description. The skill's listed trigger phrases include add an app, push to the cardputer, tail the device, run on the device, and follow-up work after /maker-setup.

Give the agent the port if you know it, such as /dev/ttyACM0 or COM3. Otherwise the agent can use the port that detect.py reported last time.

Add an app that shows a dice roll on the screen
Push to the cardputer only the snake.py file I changed
Tail the device so I can see the logs while I press keys
Run on the device a command that lists the files in /flash

Add an app and push changes without re-flashing

The skill tells the agent to start from hello_cardputer.py, the smallest example in the bundle. It shows keyboard polling, font use and exit conventions. Put your new .py file in buddy/device/apps/ and the launcher will list it on the next boot, because main.py scans /flash/apps/ at boot and shows every .py file as a menu entry.

To push the whole bundle without re-flashing, the skill uses install_apps.py. Replace the placeholder with your device's port.

Device layout: main.py is the launcher menu, buddy_*.py files are shared libraries, burst_frames.py holds sprite frames, and apps/ holds claude_buddy.py, hello_cardputer.py and snake.py

python3 onboard/scripts/install_apps.py --port <PORT> --src buddy

Push, watch and run commands on the device

For faster cycles the skill provides three scripts in buddy/scripts/. push.py sends only the files you name over USB-serial. tail_serial.py shows the device's log output. repl_run.py runs one command on the device and prints the result.

The agent fills in the port for you. You can also run these yourself, replacing the placeholder with your port.

push.py sends a subset of files, for example apps/snake.py
tail_serial.py watches device logs
repl_run.py executes a one-shot REPL command

python3 buddy/scripts/push.py --port <PORT> --files apps/snake.py
python3 buddy/scripts/tail_serial.py --port <PORT>
python3 buddy/scripts/repl_run.py --port <PORT> --script "import os; print(os.listdir('/flash'))"

Safety notes and tips

The scripts write files and run code on whatever hardware is connected to the port you give them. Check the port before running anything, especially if more than one USB device is attached. Only use the skill with a device you control.

The skill does not use the network. It needs Python 3 and a USB-serial connection.

Confirm the port matches your Cardputer-Adv before each push
Keep the device connected while tailing logs
Edit files in the local clone, then push the changed file only, to keep cycles fast

What people use it for

Adding a small menu game, such as a new app alongside Snake
Editing one app file and pushing only that file for a quick test
Watching serial logs while testing keyboard handling in an app
Running a one-off command to check what files are in /flash
Tweaking the Claude Buddy client that connects to Claude Desktop's Hardware Buddy

Frequently asked questions

What is the cardputer-buddy agent skill?

It is an agent skill that gives an AI agent instructions for iterating on the Claude Buddy, Snake and Hello MicroPython apps on an M5 Cardputer-Adv. It applies after the device is already set up with the m5-onboard skill. It covers adding apps, pushing changed files, watching logs and running single commands.

How do I install the cardputer-buddy skill?

Download the skill ZIP and unzip it into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder. You can also upload the ZIP in the Claude apps under Settings, Capabilities, Skills. Start a new session afterwards.

What do I need to use cardputer-buddy?

You need Python 3 on your computer, a Cardputer-Adv connected over USB-serial, the buddy/ directory from a local build-with-claude clone, and prior setup with the m5-onboard skill. The skill is not a first-time setup tool.

Does the cardputer-buddy skill need internet access?

No. The skill does not use the network, according to its listing. It runs local scripts that talk to the device over USB-serial.

Is cardputer-buddy free and what licence does it use?

The skill is listed under the Apache-2.0 licence. Check the licence file in the source repository for the full terms before reusing the code.

Can I use cardputer-buddy if I have not set up my Cardputer-Adv yet?

No. The skill assumes the m5-onboard skill has already run and will not help with first-time setup. Run m5-onboard first, then use cardputer-buddy for follow-up work.

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Our verdict

This skill suits hobbyists and developers who already have a Cardputer-Adv set up through m5-onboard and want faster push-and-test cycles for small MicroPython apps. It is not a good choice if the device is not yet provisioned, if you need general MicroPython or embedded help outside this bundle, or if you cannot be sure which USB port the device is on, because the scripts write files and run code on whatever hardware is at that port.

Download the skill