gc9a01

2 Articles

Spool Roller Gets Touch Screen

April 24, 2026 by 2 Comments

If you have a desktop 3D printer, you probably want something to hang filament spools on. [LVTRC] has a spool roller that fits the bill. It also incorporates a scale and a round touch screen. (Google Translate)

We’ve seen those round screens before, and now we wonder why we didn’t think of this. The GC9A01 display shows a progress ring and lets you save settings or calibrations to EEPROM. An Arduino Nano provides the brain, and the load cell connects to an HX711. The project is made to fit a specific printer, but it should be little trouble to adapt it to a different printer or to mount it in an external mount.

One of the calibration steps, of course, is to program the weight of an empty spool to subtract from the total weight. The device can store up to five specific profiles.

Not the biggest spool holder we’ve seen. We keep thinking that we don’t know why we want a circular screen, and then someone always drops in to show us another thing we didn’t think about.

Better Faux-Analog VU Meters

March 23, 2026 by 5 Comments

One of the coolest things about old hi-fi hardware is that it often came with flickety needles that danced with the audio level. You can still buy these if you want, or you can simulate the same look on a screen, as [mircemk] demonstrates.

It isn’t [mircemk]’s first rodeo in this regard. An earlier project involved creating simulated VU meters on round displays, but they were somewhat limited. Using the Adafruit GFX library on an ESP32 netted a working setup, but it was jerky and very jagged and digital-looking. It was more akin to a fake needle display running on an 8-bit computer than something that looked like a real vintage VU meter.

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