Pat Deegan

Creating a sensor or peripheral with an SPI (slave) interface
Creating a sensor or peripheral with an SPI (slave) interface

Designed to interact with a 16-bit I/O expander, the firmware was ready for testing.  Though I was still waiting on parts, I wanted to make sure it would all work as expected.  What’s an impatient developer to do?  Create his own SPI slave to replace the missing part, of course! If you’ve gotten anywhere beyond…

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Real world Kicad project postmortem and more tips
Real world Kicad project postmortem and more tips

As a follow-up to my intro/tutorial, I’ll go over a few more lessons learned using Kicad including some tips that should be of help to anyone embarking on a similar journey. The power module project was selected for a first adventure using Kicad as it was relatively small while being non-trivial.  The circuit holds around…

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Mystery black window workaround: Druid back in development

Months ago, I was forced to get a new laptop (thanksalot, kitty!) which uses an Intel HD Graphics 520 graphics card.  When I got around to working on druid4arduino I hit a mystery bug with the display, as described previously. In short, a nice black window that wouldn’t display anything but the void.  Development was…

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Kicad: Techniques, Tips and Work-arounds
Kicad: Techniques, Tips and Work-arounds

Kicad is an cross-platform, open source, electronics design suite.  I’d toyed with it in the past, but had never made it to actually designing real projects with it until recently.  Here, I’ll go over my experience and initial impressions, and provide a few pointers and resources for anyone curious about trying it out.  We’ll tour…

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Winners Adjustable DC Power Supply: Walkthrough and review

I recently received a little adjustable power supply, purchased off ebay for dirt cheap.  It’s pretty nice, so if you’ve been considering something similar have a gander at the video: It can take between 4.5 and 23V in (recommended to stay below 20V) and has a 1.5V drop-out.  It’s claimed that it can source up…

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Druid4Arduino: developments and mystery bug

The vagaries of life and a few real clients got in the way of druid2 development until recently.  I was all set to get going when the angry and fickle 4-legged god I live with changed my plans a bit… Thanks, kittie.  I’d been thinking of a new laptop anyway and managed to get one…

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Druid2: the quest for beta testers
Druid2: the quest for beta testers

Hallo all… An updated, more powerful and much improved versions of druid and SerialUI are on their way in the coming weeks.  I’m looking for a few people who’d be willing to act as beta testers for the new versions–the more hardware, and platforms, you have access to, the better but any supported combination should…

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Transmitting mounds of data in realtime over Bluetooth Low Energy
Transmitting mounds of data in realtime over Bluetooth Low Energy

My client needed to receive a relatively large amount of data on a mobile device, from an embedded system, and process it in near-realtime.   The simplest method for communication with a whole host of mobile devices is to go over bluetooth low energy, but this protocol’s main concern is more about power conservation than throughput. …

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Turning complex waveforms into usable values–VRMS, Power, Torque… how to do it and why it works

After this tutorial, you’ll know “in your bones” how to deal with the weirder stuff, when it comes to time-dependent values. It’s easy to find formulas to plug into to for simple cases, like a steady DC voltage or nice sine waves with known peak values but what happens when things aren’t so straightforward?  Say…

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Finding a messy signal’s period and frequency, the easy way
Finding a messy signal’s period and frequency, the easy way

I’ve recently had to determining the frequency of some arbitrary repeating signal, from a stream of sampled values. In a simple universe, you could just wait for a specific value to come in–say the peak value–or monitor for the zero crossing or somesuch. However, the particulars in this case included the fact that, in addition…

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