HOWTO

Midnight hack: going from SMT to breadboard in a bind

So it’s the middle of the night and I find myself in a jam… hm, a lot of my stories seem to start that way.  Anyhow, it’s the middle of the night and I’m badly stuck: I need to talk with a two-wire chip I have on a breakout, but the I²C communication lines need…

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Squeezing the most out of Raphaël JS for SVG generation

A few hints about squeezing maximum performance out of Raphaël. When you want to generate dynamic SVG images using Javascript, either on a website or within a Cordova-type project on mobile devices, the Raphaël library is pretty sweet.  Raphaël has a nice, clean, API and lets you do pretty much anything graphics-related and it sticks…

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The Handicraft Router
The Handicraft Router

This is a quick post to share a technique I recently invented (or, more likely, re-invented) that can be of great help when you’re trying to layout a circuit but are overloaded by possibilities: the handicraft router. In this specific case, I was trying to get the outputs from a bunch of digital potentiometers to…

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Rectifier/Voltage Regulator module: post-mortem
Rectifier/Voltage Regulator module: post-mortem

Needing a modular power supply that could handle a few amps and both AC and DC input, I recently designed a circuit to perform the task.  Here I’ll go over the main points and a few lessons learned.

Using the on-board Real-Time Clock
Using the on-board Real-Time Clock

So you’re programming for a platform with a built-in RTC… cool.  Now what? Most (all?) XMEGA‘s have an on-board real-time clock, some can even be backed-up by a distinct battery (like the xmega256a3bu, shown below) which can be a real time saver (oh, the pun-anity!). The question then becomes how to best use it. I’ve…

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Reliable 3G connections with Huawei E182E/E173s on Raspberry Pi

I just finished a project for which I we needed to connect a raspberry pi to a distant server, over a 3G connection.  The module was to be autonomous–it would be powered on demand and needed to reboot into a consistently usable state to perform its duties. Creating a shield (or “HAT” in Pi terminology)…

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Why (and how) you should start using XMEGAs
Why (and how) you should start using XMEGAs

I love the Arduino platform, especially for prototyping, and have been playing with the Atmel ATmega chips for a long while.  Once you’ve designed your project, some of the smaller derivatives (like the Ardweeny I’ve mentioned before) are cheap enough to leave embedded everywhere and, in any case, you can always move from an Arduino…

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Bluetooth Low Energy tutorial series (part 1) published.

I’m pleased to announce that the first set of pages for the Bluetooth Smart/Low Energy Tutorial series have been published.  Within, you’ll find a BLE crash course, a DIY BLE module breakout board (including an Eagle library so you can use it in your circuits) and a complete universal bluetooth low energy client program– with…

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What’s the easiest way send files to an Arduino?

There are many instances when it would be nice to be able to send large amounts of data to an Arduino-based device.  A very obvious example is any kind of media player, where you’d like to upload files from your computer, but there’s also sending configuration, whitelists, sets of instructions… there are many cases where…

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Quick Hack: old-school bench power supply

I went out to do a beta demonstration at a client’s office, last Thursday, and brought along the prototype circuit boards as well as a small variable power supply.  As I was setting up and pulled out the power supply–a functional but somewhat shoddy little black box with red and black alligator clips–I remarked that…

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