Eric Luo — computer engineering student and maker. Build logs and notes on embedded systems, digital fabrication, and the web.https://ercluo.com/https://ercluo.com/blog/put-an-led-on-it/https://ercluo.com/blog/put-an-led-on-it/The cheapest debugging tool in electronics is a resistor and a light. How blinkenlights carried a 14-breadboard CPU build, and what they replace.Sun, 28 Jun 2026 00:00:00 GMThardwaredebuggingcpu-buildhttps://ercluo.com/blog/thermal-paper-appliance/https://ercluo.com/blog/thermal-paper-appliance/A receipt printer that only prints notes is more useful than an app that does everything. Notes on building the LAN printer and why constraints made it good.Thu, 14 May 2026 00:00:00 GMTembeddedprintersdesignhttps://ercluo.com/blog/nine-prints/https://ercluo.com/blog/nine-prints/Iteration logs from the cone light modifier: what each failed print taught me about tolerances, surfaces, and knowing when to stop.Thu, 19 Feb 2026 00:00:00 GMT3d-printingphotographyprocess