Q&A on Using Reed-Solomon in Low-Power RF MCU

January 14, 2015

Recently I had an email exchange with an engineer curious about the encodings I’ve implemented in DASH7 and HayTag to squeeze-out maximum range.  An important part is simply the Convolutional Code FEC hardware that’s available in SPIRIT1, CC1101, CC12xx, and the new AX5243.  However, in open spaces I can get even more performance by employing a […]

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Using 32 bit Sync-word for 6 bit Addressing

January 10, 2015

Just a quick post today: Here is a list of 64, 32 bit syncwords which can be used to deliver implicit 6 bit addressing.  I wrote several computer programs to exhaustively inspect and test the 32 bit number field, in order to come-up with this list.  These sync words are all high-performing, and as individual […]

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Notes on Designing for Solar Energy Harvesting

January 4, 2015

While designing the HayTag across a period of two years, I found myself spending a lot of time not only in design and test, but also consulting with the solar panel manufacturers, battery manufacturers, and semiconductor manufacturers that make the charging ICs.  I want to write down some of the lessons I learned. I’m still […]

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Atmel SAM D is Unimpressive at First Glance

November 30, 2014

As some readers may know, on the side I have been working to do a couple of things that I expect will improve the lives of advanced Arduino users: Integrate Arduino with the OpenTag RTOS, such that Arduino sketches run as threads yet have direct access to HW, with mutex-like features if you want them.  This […]

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Review: STM32L vs. MSP430F5 (Part 1)

October 8, 2014

Lately I’ve been pushing the STM32L to the limit for the HayTag project, and possibly past the limit depending on how you feel about hardware hacks. This is a new challenge, because for years I’ve been doing the same with MSP430F5, as it used to be the de facto platform for OpenTag. They are both […]

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Otter: a Client-side Binary Shell

August 4, 2014

I’m working on-the-side on a project I named “otter.”  It is short for “OpenTag Terminal,” and the GitHub page is here. Yes, it is a companion project for OpenTag, but I think it may become popular for all kinds of embedded projects.  Since the shell runs on the client-side (the user’s PC), the protocol overhead […]

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Fixing & Servicing a Krups FCB4 Convection Toaster

January 5, 2014

In June 2007, I bought a Krups FCB4 (Amazon Link).  It is a fantastic piece of kitchen equipment, and I’ve used it hard over six and a half years.  However, the heating elements were worn out and I wanted to replace them.  One of the great things about products from German companies is that you […]

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Optimized Software CRC5 for USB

October 13, 2013

Today I was inspired by this article (A Fast, Compact CRC5 Checker for Microcontrollers) to do a better job at the same thing. So, I developed a 6 + 5 bit bi-tabular method for computing and checking the CRC5 used in USB.  I’ve validated it against known USB reference values.

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Java for Embedded: Fat Chance

July 28, 2013

The magazine “Javaworld” has published an article that quoted Christopher Rommel, who is a research analyst most likely getting paid by Oracle to say things they want.  He may or may not be related to the great Erwin Rommel, but probably not.  Here’s the quote: “There’s just a growing interest in object-oriented languages and a […]

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Fitbit One Teardown (i.e. Hadron Tracker)

June 10, 2013

Last week, super-intern Dennis and I tore down a FitBit One.  We took a bunch of decent pictures, and we made one crappy video.  Stay tuned this week, I’m assembling a very long blog post.

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