Build a $10 Token Monitor for LM Studio Using an ESP32 Display

Repurposing cheap hardware for AI workflows is a hacker tradition. A Reddit user just turned a $10 ESP32 weather station display from AliExpress into a live token-per-second monitor for LM Studio. The display is a small 240×240 pixel screen typically sold as a Bitcoin ticker, but the generic clone wouldn't run the original GitHub projects. Enter Codex: the user asked Claude Codex (likely Anthropic's coding assistant) to write custom firmware, and within 15 minutes had a functional token monitor.

The project relies on the ESP32's WiFi to fetch token rate data from LM Studio's API. While the post doesn't include the exact code, the approach is straightforward: poll LM Studio's local HTTP endpoint (usually http://localhost:1234), parse the token generation speed, and render it on the small round display. The display uses the ST7789 driver over SPI, common among these AliExpress modules.

Key details from the post:

• Hardware: ESP32-based 240×240 round LCD display (sold as weather station / Bitcoin ticker) from AliExpress for ~$10.
• Firmware: Custom-written using Codex in about 15 minutes.
• Function: Displays live token generation speed (tokens/second) from LM Studio.
• API endpoint: LM Studio exposes token rate via its local API; the ESP32 polls it over WiFi.
• Driver: Likely ST7789 (common for 240×240 TFTs).

The user notes that their specific display clone didn't support existing GitHub projects for these screens — arguably a common problem with generic AliExpress hardware — but Codex handled the adaptation quickly. No special libraries beyond the standard ESP32 Arduino core and TFT_eSPI were mentioned.

This is a neat weekend project for anyone running LM Studio locally. The total BOM is under $15 including the ESP32 board (though many of these displays have the ESP32 integrated). The main challenge is getting the token rate endpoint details from LM Studio — check its API docs for the exact path.

Who it's for: Developers running LM Studio locally who want a physical, real-time token rate display without spending >$50 on an external monitor.