Archive of open source

Using the inductor tester Thumbnail

Using the inductor tester

Posted by ian.rees on May 21, 2016 in Projects tagged with , , , , , , ,

A few weeks back, we had a talk on KiCad (presentation available at http://ianrrees.github.io/KiCad_talk/ ) where we ordered some PCBs to make an inductor tester (Henryometer?) from dirty PCBs. Those boards came in this week, and a few folks have already put theirs together. This post aims to be a quick guide to the usage of the tester; if you'd like to build one yourself just let Ian know, parts cost is $15. You'll need an oscilloscope and a current-limited DC power supply to make use of it. Connections between the tester and oscilloscope are made via standard BNC coaxial cables (ava

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Debugging AVRs (without Atmel Studio) Thumbnail

Debugging AVRs (without Atmel Studio)

Posted by ian.rees on December 07, 2015 in Projects tagged with , , , , , , , ,

This post is somewhere between a guide and a collection of notes, aimed at debugging programs for AVR microcontrollers (like the ones in most Arduinos) "on target". We'll be using an AVR Dragon connected to the target micro via the normal 6-pin programming header, with a Mac or Linux PC as the host. Although this is a bit more advanced than most of our other projects, it's really quite approachable and is a very powerful technique for fixing AVR software problems. From a high level; we'll use a debugging program on a Mac (or Linux, Windows, etc) "host" computer, which communicates with a Dragon "In Circuit Emulator" (ICE) via USB to debug a buggy program running on the "target" AVR, which is presumably running in some circuit we're interested in. Small variations might apply for Windows hosts, using JTAG instead of DebugWIRE, other debugger tools (Atmel JTAGICE mkII for example), etc.

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Talk: OpenWRT Thumbnail

Talk: OpenWRT

Posted by Micheal Hamel on August 08, 2011 in Talks tagged with , , , ,

OpenWRT: thats an odd name... The story starts late 2002 when Linksys released a wireless router called the WRT54G. Andrew Miklas noticed (from the visible names used in the internal filesystem, amongst other things) that it was using Linux, without in any way acknowledging this or making the source available. They had obvioulsy modified Linux to get it to run on their hardware. This is a violation of the Linux license, the GPL. He tried contacting Linksys who weren't immediately co-operative, so he posted to the Linux Kernel mailing list and Linksys came under considerable pressure to release their source. Linksys then released the source, and people started rebuilding and fiddling with it. They actually had started patching the binary firmware before Linksys did this. A number of different projects appeared, one was OpenWRT which is first named as such in Jan 2004. So its 7-8 years old.

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