Exporting Gerber Files From Eagle CAD


While services like OSH Park let you upload your Eagle CAD files directly for PCB manufacture, most other services, especially production runs, require the industry-standard Gerber files. Essentially a set of text files for each part of the board (ex: top copper, bottom silkscreen, bottom solder-mask, etc), generating Gerbers in the right format can be a bit tricky.

This tutorial walks you through this process, with a specific example of sending files to Seeed Studio’s excellent PCB service (no financial stake here – just like their service!). However, you could use these directions for most any fab house.

Special thanks to Luca Dentella’s post that helped me figure out this process.

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Simple VU Meter Circuit


I recently bought a cheap VU meter on Amazon, which looks very cool but needs some circuitry to get running. Unlike vintage meters, which can be driven by the audio signal directly, newer (and especially cheap) meters require DC current. A simple circuit, based on this example by Rod Elliott, uses four diodes to convert the AC audio signal into DC, plus a resistor and capacitor to dampen the movement of the needle.

See Rod’s post for lots more technical detail and a more complex driver circuit. Of course, this is pretty lo-fi and not studio-quality equipment… it also didn’t cost $1000.

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