CheapStat: An Open-source Potentiostat

September 14, 2011 by Mike Szczys 12 Comments

A commercial potentiostat can cost several thousand dollars, but the CheapStat is an open source project that makes it possible to build your own at a tiny fraction of that cost. It is possible to build one for less than $80, breaking down the cost barrier faced by many labs that would like to have this test hardware.

A potentiostat is used to measure electrochemical properties. To give you a few examples of what it can do, the hardware can measure arsenic levels in water, Vitamin C concentration in orange juice, Acetaminophen concentrations in over-the-counter medications, and a bunch of other less easily explained tests having to do with chemical compounds and DNA.

The device makes use of an Atmel XMEGA microcontroller and connects to a computer via USB. A Java program grabs that data from the hardware displaying test results on your choice of computer platforms. If you’re looking for all the gory details you won’t be disappointed by their journal paper.

Ever Wonder Where Cool Interactive Museum Exhibits Come From?

August 9, 2011 by Mike Szczys 13 Comments

[Victor’s] girlfriend works at a museum and enlisted his expertise in designing an interactive detective game for kids visiting the museum. The vision was for the kids to discover phone numbers that they could call for clues. Originally he planned to display the clues on a character LCD, but obviously it’s much neater to hear the clues in the handset of the phone.

Quickly switching gears, [Victor] dropped the ATtiny2313 and started over with an Xmega chip — in fact, it was our recent Xmega post that inspired him to document his project. The microcontroller is responsible for a lot of goings-on. It scans the key matrix for inputs, simulates the DTMF touch tones, reads audio files from a FAT file system on an SD card, and plays them back over the hand set’s speaker. Since most of the hardware is already built into the phones, it was not hard to fit his add-ons inside the case. A simple audio amplifier circuit joins the microcontroller, which is patched into the rows and columns of the keyboard. Take a gander at the video after the break to see the device in action.

Continue reading “Ever Wonder Where Cool Interactive Museum Exhibits Come From?” →

Regarding Atmel’s Xmega Chips

July 26, 2011 by Mike Szczys 35 Comments

A few years back Atmel announced a new line of chips, the XMega series. We see the name bouncing around here and there, but when [Michael Kleinigger] mentioned that he’s seen very few project using these chips we realized that not only is he right, but we know next to nothing about them. Just give his XMega review post a whirl and you’ll be up to speed in no time.

He compares an XMega128A1 side-by-side with an ATmega1280. For those that abhor reading paragraphs full of words, there’s a table that can give you the quick facts like how the XMega costs less and runs faster. But we know from past discussions (like the one on PWM) that [Mike] knows his stuff so the whole thing’s worth a read. He’ll lead you through the programming tool chain (which hasn’t changed), a bit about the new event system, and then finish with a demo program on the Xplained development board.

Xprotolab: Oscilloscope And Xmega Development Board

February 17, 2011 by Mike Szczys 27 Comments

Here’s a nice hands-on overview of the Xprotolab, a development board based around the AVR ATxmega32A4 microcontroller. The tiny DIP package includes an OLED display, four tactile switches, and it can be powered via a micro USB connector. The device ships ready to use as a two-channel Oscilloscope, but check out how small it is in the video after the break to decide if this will actually be useful for you. It’s not that it doesn’t have a lot of features, in fact it’s packed with them, but that screen is quite small for meaningful work. Still, at $35 it’s an inexpensive way to get your hands on the hardware and acquaint yourself with this line of microprocessors. Not that in order to flash new firmware you will need a PDI capable programmer. Continue reading “Xprotolab: Oscilloscope And Xmega Development Board” →

Data Logging Football

January 9, 2011 by Mike Szczys 6 Comments

[Ben Kokes] threw together a hardware package to capture data from a football. In the center of a Nerf football he made room for an accelerometer, gyroscope, and an electronic compass. All three can capture 3-axis data and, along with the LEDs ringing the circumference, they’ve controlled by an XMEGA192 microcontroller.

This makes us think back to a time when baseballs with a built-in speed sensor first hit the market… does this hack have mass marketing potential? Perhaps, but only if the $225 sensor price tag were greatly reduced. When we first started reading the description we hoped that [Ben] had coded an interpreter that would render 3D playback video from the data. He hasn’t done that, but from the data graphs he did assemble we don’t think that functionality is out of the question. We’ll keep our fingers crossed.