Refurbishing A Refrigerator For Fermenting

January 25, 2011 by Caleb Kraft 12 Comments

[Mikey Sklar] wrote in to show us how he refurbished a neighbors useless refrigerator as a fermentation chamber. [Mikey] is a fan of making breads, kemchi, yogurt, and tempeh. To make these, it helps to have a completely controlled temperature for them to ferment in. [Mikey] developed a temp controller for this in the past, but had to either build a control box or use a giant chest freezer. This is not optimal for limited space, such as a kitchen. He got lucky when a neighbor tossed a wine cooler into the trash. These little coolers are perfectly sized for a kitchen and even have a glass front so you can keep an eye on what is going on inside without having to open it and effect your temps. [Mikey] ripped it open, replaced the peltier cooler with a large heat lamp and his temp controller. Since he was making yogurt with this one, he needed only to heat it. The final product turned out pretty effective.

Bluetooth Temperature Module

December 10, 2010 by Mike Szczys 11 Comments

Wanting to know the outside temperature, [Jamie Maloway] built his own temperature sensor that can be read with a Bluetooth device. Let’s take a tour of the hardware above from right to left. There’s a linear voltage regulator with two filtering caps and a terminal block to attach a 9V battery or other power source. Next there’s an 8 MHz crystal and it’s capacitors, followed by a programming header on top and a 1-wire temperature IC, the DS18B20 we’re all familiar with hanging off the bottom. These both connect to the 8-pin PIC 12F675 that drives the system, and transmits using a Bluetooth module from Sure Electronics. Since this is using a serial protocol and transmitting ASCII data, it can be read using an automated script, or simply by using a terminal program.

Now, who’s going to be the first to get rid of the battery and leech off of the mains through inductance?

Skillet Reflow Controller

December 9, 2010 by Mike Szczys 21 Comments

Using an electric skillet to reflow surface mount circuit boards is a popular alternate use for those kitchen appliances. The real trick is monitoring and controlling the temperature. [Mechatronics Guy] built his own skillet temperature controller using a thermistor, a solid state relay, and an Arduino.

He was inspired by [Ladyada’s] work which used a servo to adjust the temperature dial on the skillet’s power supply. This started by attaching the thermistor to the bottom of the skillet using JB weld. since this area will be heating up he also attached a terminal block for connecting the feed wires as the heat would melt any solder joints. Those wires travel back to a control box housing the Arduino and solid state relay. To gain finer control over the heating element the relay is switched on and off, resulting in low-frequency Pulse Width Modulation, which should help maintain a consistent temperature better than just turning the temperature dial on the cord.

Pair this up with the vacuum tweezers hack and you’re on your way to a surface mount assembly line. If you want to see this process in action check out this post. It goes from stenciling, to populating, to reflowing in a toaster oven.

[Thanks Rob]

In-button Display For Your Car’s Dashboard

November 15, 2010 by Mike Szczys 17 Comments

Here’s an interesting take on augmenting a car’s dashboard. [Daniel] is using a button blank to house a 1″ OLED display in his Jetta. It shows auxiliary data such as boost pressure and several sets of temperature readings. The display itself has a tiny little circuit board with a PIC 24 to drive it. A larger board, seen above, collects the temperature data from some sensors that [Daniel] added as part of the hack. There are some pictures of the installed display inside of the dark car and it looks really easy to read. It also sounds like there’s some dimming functionality built into the firmware. This is the easiest way we’ve seen to add a display to your dashboard as it just requires you to pop out a button blank, rather than disassembling the entire console or patching into what’s already there.

Chest Freezer Temperature Controller

November 5, 2010 by Mike Szczys 11 Comments

[Mikey Sklar] finds himself in need of a temperature regulated refrigerator for fermenting foods like yogurt, kimchi, bread, and beer. After some testing he found that by building his own controller he can get a chest freezer to outperform an upright refrigerator at this task by 2-to-1.

The controller is based around an ATmega48. It includes a remote temperature sensors which you can see connected to the lower left header in the image above. On the back of the board there’s a relay used to switch the freezer’s power on and off. [Mikey] is selling a kit but the hardware and software for the project are both open source so build it yourself if you have the know-how.

A chest freezer is a great place to store Cornelius kegs… we’ll keep our eyes open for one.

Shiny Motorcycle Computer

October 16, 2010 by Mike Szczys 19 Comments

We’re rather surprised at how popular it has become to build your own motorcycle computer. [Mario Mauerer] tipped us off about his shiny motorcycle computer (translated) for his Yamaha XTZ 750. It uses an ATmega644 microcontroller to pull a variety of data together and display it on this white LED backlit display. He connected a flow meter to the fuel line to monitor gas consumption. Oil temperature is captured by inserting a brass tube (containing the sensor) through a hole in the oil cap and soldering it in place. Water temperature is gathered by measuring the external temperature of one of the cooling lines. [Mario] uses a rotary encode with a click function as the control interface device, and a battery backed real time clock keeps time.

A quick look at the PCBs tells the tale of good circuit design. But we do wonder about catching the reflection of the sun in that shiny bezel.

In-dash Motorcycle Display

August 24, 2010 by Mike Szczys 26 Comments

[Muth] added an auxiliary display to his motorcycle instrument panel. He started out prototyping with a PIC 16F877A which he used to access information through the ECM diagnostic connection. Once he had that working he found this tiny display which fits perfectly between the speedometer and tachometer. There’s a short demo after the break where you can see a past-30-minute history of the Adaptive Fuel Value and the engine temperature as well as a secondary information screen.

This is another nice addition to our collection of vehicle displays, scooter controllers, gear indicators, and motorcycle computers.

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