Recent Posts
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Meet the Motorola MC6809
The MC6809 was an 8 bit microprocessor designed by Motorola in the late 70’s. It holds a special place for me because when I was first working in the software industry it represented the pinnacle of microprocessor design for that era. It was never used much, 16 bit processors came out soon after and the…
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Placid
Placid is a cross-platform operating system for embedded systems. It can run on platforms as small as Arduino and ESP8266 all the way up to Raspberry Pi. The source code is available with an MIT license from GitHub. Motivations I started thinking about bare metal programming on the Raspberry Pi when I tried running OctoPrint (https://octoprint.org)…
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Quick Project: New Life for Clock
I have this Frank Lloyd Wright desk clock. I love the art and simplicity of it. In fact I love it so much that I’ve had it on my nightstand for 2 years without it working! The problem is that the single AA battery last for less than 2 months and I finally got tired…
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Putting Data in ESP8266 Flash Memory
The ESP8266 has precious little RAM. You start with a little over 80KB, but the system takes up over 20K of that just for wifi and other required functionality. So best case you get under 60K of RAM for your use. In fact, if you use the Arduino toolchain you’ll be lucky to be left…
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Multicast DNS Tribulations
For my m8rScript project I really want to use Bonjour. It would give me a way of finding many ESP8266 devices on the network without having to nail down IP addresses. The concept is simple: you give your device a name, like yardweather. Then you type yardweather.local into your web browser and up pops the…
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m8rScript
Embedded microcontrollers are amazing. For a few dollars you can have a postage stamp sized device with 500K of RAM, multiple megabytes of Flash ROM, Wifi, Bluetooth and lots of I/O. You can connect up displays for clocks and connected information terminals, add sensors to make your own weather station, ot hook up addressable LEDs…
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Easy Library Table
My kids are in high school now so I thought it was time they had nicer desks than the ones we got them at Ikea. I wanted to make something that would last, that they could take with them to college and beyond. I also decided I didn’t want a desk with drawers on the…
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Joinery for the Everyday Woodworker
Probably the most important skill for any woodworker is joinery. Attaching pieces of wood to each other is required on most any project and if it needs to withstand any kind of load you need a good strong joint. There have been lots of joinery techniques through the centuries, but modern techniques (together with modern…
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Remote Access Howto
Here’s the situation. You installed this cool sprinkler controller. You used a DHCP reservation so it’s always at the same ip address. Now you can always access it – as long as you’re connected to your home network. What if you’re in Hawaii? You’re sitting on the beach, sipping a nice drink from a coconut,…