Magic Mote Thermostat and Wireless Temperature Sensor

A homemade thermostat up in the basement rafters controls the heating in my home. The smart bit is the radio frequency communication that connects it to a remote temperature sensor.

Magic Mote Wireless Sensor Node

This compact PCB interfaces a low power MSP430G2553 microcontroller with a Nordic NRF24L01+ 2.4 GHz radio frequency transceiver module. It's well adapted to serve as a wireless sensor node, but has enough I/O options to be put to use wherever a small microcontroller is required. PCBs now available from Tindie!


Home Grown Bhut Jolokia Peppers

Hannah and I made chili sauce from the devilishly hot Bhut Jolokia peppers that I grew this year.


12mm Rotary Encoder Breakout

0.925" x 0.925" breakout board for 12mm rotary encoder with switch. The PCB has enlarged holes to fit generic encoders.


Booting Linux Live USB on a MacBook Air

I have a MacBook Air with an Intel i7 core running OS X Lion 10.7.5. Booting linux from a flash drive was not straightforward, to the point that when I finally got it working I laughed with surprise. Evidently doing such things is not part of the one true Apple way. The instructions were cobbled together from from here and here with a fair bit of trial and error. Needless to say, the procedures documented on the Ubuntu website did not work for me.


Stirplate Hot Fix

A digital stirring hotplate in decent used condition will set you back about $250. I paid a fraction of that for one with a broken heating function. The problem turned out to be nothing more than a duff switch.


I Wanted A Puppy For Xmas

... and Digikey made my wish come true. I'm planning a home automation system, and this little computer will be its brain.


Homemade MSP430 Launchpads

When I ordered some NRF24L01+ boosterpacks from the 43oh store, I asked for a couple of MSP430 Launchpad v1.4 PCBs. These are legacy boards kindly provided by TI (thanks LariSan!) It was fiddly soldering to the tiny 0402 pads since my components were all 0805. The LEDs were especially tricky. But they both turned out OK as you can see. Here they are (alongside a genuine Launchpad on the left) running the breathing LED demo from the OSX Launchpad toolchain.


A Little Something To Be Thankful For

Thanks Elecrow for a $10 voucher in their Black Friday giveaway. I have heard good reports about their PCB prototyping service, especially the free color option, and I am keen to give it a try.


Pedal Powered Menorah

Exercise bike + magnets + LEDs = festival of light. Devised by T.J.Hunt with specialist engineering expertise from Rabbi Shena Potter Jaffee. Come along 3rd December to the Mayerson Jewish Center of Cincinnati. Pop a beer, grab a latke, and take a spin. Happy Hannukah! 


Twin Triac AC Switch on DP5050 PCB

Two triacs switched by zero-crossing optocoupled drivers act as solid state relays on a Dangerous Prototypes standard size PCB.


Twin Relay Control Board on DP5050 PCB

Just for good measure, a breakout board for twin Songle SRD series relays to fit the Dangerous Prototypes standard PCB size DP5050.

Relay Control Board on DP5031 PCB

Here's a breakout board for those Songle SRD series relays that are so cheap on Ebay. It fits nicely on the Dangerous Prototypes standard PCB size DP5031.


November Swag Bag: Double Freebies

Last week I won the weekly trivia quiz from Tier1Automation, and came dead last in the 43oh Halloween competition with my Jack-O'-Launchpad — but still won the booby prize of 2 MSP430 Launchpad v1.4 PCBs. The freebies arrived in the same post. Good times!

Bike Handlebar Hack

Now here is a real hack. As in, something that can be accomplished by hacking, with a hacksaw. Although in fact it was an angle grinder that I used to streamline my handlebars, lopping off 13 cm (5" or so).

Bike Rack From Scrap Fence

Something had to be done with the heap of bikes in the garage. Fence panels welded along the edges made for a quick and cheap solution.

Stripboard PID Arduino Shield, Part 4: Thermocouple Interface

The diagram shows how to connect an Adafruit MAX31855 breakout board to the stripboard Arduino PID shield. Vin should connect to the 5V pin and DO, CS, and CLK to A0, A1, and A2 respectively. Connect a K thermocouple in the screw terminals. If the temperature reading goes down when it should go up, switch the thermocouple wires around.


Stripboard PID Arduino Shield, Part 3: Serial Interface

The graphical user interface allows every feature of the Arduino PID controller shield to be governed remotely via the serial interface. A powerful additional feature is the ability to set multi-stage temperature profiles for applications where the set point changes over time.

Stripboard PID Arduino Shield, Part 2: Firmware

Install the code base for the stripboard Arduino PID shield and get started using it as a standalone temperature controller.

Stripboard PID Arduino Shield, Part 1: Hardware

This easy-to-make shield converts your Arduino into a full-featured PID controller.



Perhaps not the most imaginative used of a Tiva Launchpad, but the default application makes for a serviceable Jack-O'-Lantern. Powered by a USB adapter from CUI, a freebie via @digikey on twitter. Nice!


30 Second Light Sabre Autopsy

What we have here. A battery holder, 2 tactile switches, 4 LEDs, and a chip with a blob on that makes a crappy noise. I don't even want to know how the plastic shaft got broken but no ambulances were called. Nothing to salvage or Halloweenify. Let's move on.


LED Dimmer PWM Hack

This cheap dimmer is designed to blink LEDs with a variable duty cycle. The default frequency can be altered by swapping out a single capacitor. 20 kHz makes a whine-free speed control for a DC motor, 1 Hz gives slow PWM for high power resistive heating loads.


Solid State Relay Module

This solid state relay propels a puny logic signal into the big time, switching up to 20 Amps of mains electricity.


Stripboard I2C Logic Level Converter

A very easy logic level converter to translate I2C signals from, say, a 5 V Arduino to a 3.3 V slave device.


I2C LED Display From Hacked Voltmeter

LED voltmeters are a cheap source of 7 segment displays and can easily be repurposed. Using the I2C protocol, a master microcontroller such as an Arduino Uno can govern multiple displays with just 2 I/O pins.


Free Shower

A street scene in Philadelphia: the first city in the USA to have fire hydrants.


Bike Trailer Welded From Trash

A cargo trailer is a great bike accessory, especially if you can weld one together for next to nothing. This artifact bears a slight resemblance to a bed frame on wheels. There's maybe a reason for that.


PID Controlled Egg Incubator

While on vacation I impulsively bought fertile chicken eggs from a farm stall. Needing to incubate them immediately, I cobbled together a rudimentary incubator from a styrofoam cooler and a few bits and pieces. A PID controller was the perfect device to govern the temperature.


Jumbo Bristlebot

With a bit more power this might make an autonomous floor scrubber. Maybe. OK, a lot more power. :)


Easy Benchtop Power Supply

Converting an ATX power supply is a great way to get juice to your electronics projects. With the ATX breakout board from Dangerous Prototypes you can do it while waiting for your toast to pop up, and it looks pretty good too.


Folding Brew Stand

I wanted a low table on which to set up my brewing gear. It would need to support a couple of hundred kilos and fold flat to the garage wall. Failure could send 100 litres of hot liquid and a variety of electrical power equipment crashing to the floor. Neanderthal design principles seemed appropriate to my levels of sophistication and skill, so I hacked together this clunky hinged table top.


Welder Rehab & Foot Switch

In which I buy an old school welder off the friendly neighbourhood chopper freak, fix it up, make an illuminated foot switch for it (which works although I have no idea how), and start gluing things together with hot metal, badly. Like warty Oscar here.


Lightweight Chicken Tractor

To shelter my chickens I needed a cage that was easy to build, light enough to be moved around the lawn, and that provided a cosy roost and nest box.


April Swag Bags

Thanks to TE Connectivity for their promotion via the Digikey twitter feed. My laptop fits in the backpack perfectly - just right for cycling. I was doubly surprised when Digikey sent me another the next day. But then, I like coordinated luggage. The third one is in the mail, right? ;-)


@YT2095 Magic Mouth v1.0 Build

Yours Truly (@YT2095) is putting together a Magic Mouth v1.0 speech synthesis shield for his Saturday morning project! Just for fun, I sent him one the PCBs I had got back from Seeedstudio's FusionPCB service. He's substituted a potentiometer for the thumbwheel trimmer, and it looks like one last header and the jack socket still need to make it onto the board. It's looking good, John. :)


Cool and Curly Counterflow Chiller

The Magic Smoke Brewhouse is a fine place to chill. Especially since we put together this heat exchange coil for cooling wort.


February Swag Bag: ITead Studio Xmas gift

ITead studio sent Christmas gifts to followers of its Twitter feed. I was thrilled to receive a blue 20x4 LCD display and PCB test card. Thanks guys — and Happy New Year!


Converted Cooler Mash Lauter Tun

It's long past time to start making beer again at the Magic Smoke Brewhouse and Grill. The best place to start is at the heart of the brewery: the mash lauter tun, or MLT.


January Swag Bag: DE0-Nano

I was a lucky entrant in Digiwish 2012, winning a DE0-Nano FPGA development board. Thanks Digikey for making my Christmas wish come true!


£1 Lithium Ion Battery Charger

One cheap PCB from an auction site. 1 scrap bit of copper pipe. 2 bronze pennies. Put them together and charge up a 18650 Li ion cell.


3x Battery Teardown

So if you open up a 9 V battery, you find 6 thin 1.5 V cells inside. But what was inside that lantern battery, the rechargeable PP3, or the funny shaped lump on the back of my laptop? Confronted with dead metal in the recycling drawer, I tried to find uses for the contents.

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