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]

Knitting Machine Hack By Keypad Emulation

December 6, 2010 by Mike Szczys 3 Comments

[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.

They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.

Arduino Electronic Speed Control Explained

November 26, 2010 by Mike Szczys 29 Comments

You can salvage some nice motors out of optical drives but they can be tricky to control. That’s because brushless DC motors require carefully timed signals used in a process called Electronic Speed Control (ESC). [Fileark] built and ESC using an Arduino and has a couple of posts explaining the concept and demonstrating how it works. His test circuit uses six 2N2222 transistors to protect the Arduino from excessive current. You can see six red LEDs above which are inline with the base of teach transistor. This gives visual feedback when a transistor is switched, a big help for troubleshooting your circuit.

Once you’ve seen the videos after the break you’ll probably come to the conclusion that this is an impractical way to use a brushless motor. But it is a wonderful way to learn about, and experiment with the concept of ESC. Chances are you can get your hands on an old optical drive for free, making this an inexpensive weekend project.

Continue reading “Arduino Electronic Speed Control Explained” →

Building A Bandwidth Meter

November 24, 2010 by Mike Szczys 15 Comments

Here’s an analog bandwidth meter made to look like an old pressure gauge. It’s actually new, but the paper showing the graduated scale was stained in a bath of black tea, then dried in an oven to give it an aged appearance. We think it’s quite effective.

The dial itself is a volt meter driven by an Arduino in much the same way as the multimeter clock. Bandwidth data is pulled from a Linux router, filtered down to the target data using ‘grep’, and sent over the serial connection by a Perl script. Since the meter itself is just waiting for serial data, alterations to the router’s scripting make it easy to represent a count of unread emails, tweets, or whatever data your code can scrape.

[Thanks Ben]

Interface Up To 12 Servos Using Arduino

November 24, 2010 by Mike Szczys 5 Comments

[Brian] is using an Arduino to control multiple servo motors. This is nothing new and has been happening since the earliest days of Arduino. But rather than develop a project and share it, [Brian] did a fantastic job of making the code scalable, readable, and even explained how the different parts work.

His code listens for serial commands and manipulates the motors accordingly. He wrote a Python script using pyserial which talks to the Arduino. As an example, he uses a joystick to send data for X and Y axes as well as pitch and roll. Want to know how those serial communications work? He explains that in detail. He also outlines the process of scaling up from the 4 servo demo to 12 servos on a standard Arduino. Sounds like it might be time to build your own version of a mouse-controlled Lynxmotion arm using the tools [Brian] has put together.

Arduino + Java + Joystick

November 19, 2010 by Mike Szczys 14 Comments

Interfacing your own hardware with a Java app couldn’t be easier than this example. [Pn] created this proof-of-concept using an Arduino, an analog joystick from a gaming controller, and a few lines of Java code. The Arduino reads an ADC value from the joystick’s x-axis and transmits it over the serial connection ten times a second. The Java program triggers on every serial event, parsing the data based on the @ symbol that the Arduino sends as a start and end condition.

We like this kind of example because there’s nothing extra involved. It lets you take the concept and run with it in any project imaginable. Be it a more complicated Joystick, or simple sensors that you’d like to interface with.

Nixie Tubes Live In A Cool Box

November 13, 2010 by Mike Szczys 8 Comments

This set of four Nixie tubes display the number of people following bildr on Twitter. That’s neat; it uses an Arduino and some open source driver boards. But what caught out eye is the enclosure. The image above shows only half, but when assembled it’s a nice little cube that keeps the insides safe. This was laser cut using the Ponoko service and kicks off a design contest. Come up with the best idea for using 4 Nixies, their drivers, and $50 worth of Ponoko’s services and they’ll give you the materials to make it happen.