CYD Studio › Docs › FAQ
Frequently asked questions
Which boards are supported?
The ESP32-2432S028R ("Cheap Yellow Display"), the NodeMCU ESP8266 and an ESP32 with a 128×64 SSD1306 OLED. Adding a board means one cyd.py (with a feature map) and a config example; the core does not change. Details: Boards and firmware.
Do I need to compile anything?
No. Ready-made firmware images are in the repository. You flash once, deploy once; after that everything happens in the browser. Rebuilding the firmware is only needed if you change the core (device/*.py, boards/*/cyd.py); that is one command too, but it needs WSL/Linux and ESP-IDF.
Why MicroPython and not Node.js or C#?
It is the only solid option that gives "write in the browser, run instantly" on this hardware. Node.js is impossible (V8 wants ~50 MB of RAM, the board has 520 KB); C/C++ and .NET nanoFramework need a PC build for every change.
Why do the numbers say "measured"?
Every RAM figure, stop latency and project count in the docs was measured on the real boards over the serial port, not estimated. If the board, firmware or core changes, the numbers change; measure again.
Can I use HTTPS or BLE?
Not next to the panel: internal DRAM is too tight (a TLS handshake needs 40–50 KB of contiguous DRAM, BLE 33 KB). Both work in Solo mode, where the board reboots with all the RAM for one project; RESET brings the panel back. Tell users "it works in solo mode", not "BLE does not work".
How many projects run at once?
On the CYD with the custom firmware, 7 small normal projects side by side were measured (the limit is the heap), plus 2–3 threads. On the NodeMCU, 3 normal projects. A display-drawing project takes 25–33 KB of heap; it is healthier on its own. Details: Run modes and memory.
Why does the Stop button sometimes reset the board?
If a project does not check should_stop() or never calls cyd.sleep, it cannot be stopped gently. If it is the only one running the board resets after 3–5 seconds and is back with the panel in ~8–10 seconds; if others are running it is flagged "stuck" and a force button appears. Follow the contract and there is no reset.
The panel does not come up; what state is the board in?
python tools/bootlog.py COM3 20 resets the board and shows the boot log. It is off, in solo mode (press RESET), crashed at boot, or stuck at the REPL after mpremote (deploy.py --reset). If it could not join WiFi it opens its own access point: CYD-Studio / cyd12345 → 192.168.4.1.
The board is on WiFi but I cannot reach it from the PC
A VPN on the PC can cut off the local network; ping the router. A CYD powered through a USB hub may drop off USB when WiFi starts but keeps running on WiFi. Make sure the static IP is in the same subnet as the PC.
Who can share in the Workshop, and what?
Anyone. Anonymously with a nickname or with a Nuvaka account. Only .py, .txt, .md; 2 MB per file, 5 files per project, 20 files per hour. Shares are MIT licensed. Details: Workshop and Store.
Does the panel's Store tab need the board to reach the internet?
No. Your browser asks cyd.nuvaka.com, downloads the file and writes it to the board's /api/save endpoint. The board only needs to be on the local network; the browser needs the internet.
Is it free?
Yes. The code is MIT licensed on GitHub, the site and the Workshop are free. The boards cost a few dollars.
What did Claude Code do?
Running the measurements on the boards over the serial port and recording them, some of the tooling and test scripts under tools/, keeping the project notes and generating the on-board handbook and the Workshop Notebook from them. Details in the repository README.
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