Arduino Oscilloscope At Five Megasamples Per Second

July 8, 2013 by Mike Szczys 45 Comments

There’s no substitute for a proper oscilloscope on your electronics bench. But unfortunately we still don’t have one of our own. But we’ve got an Arduino board and paired with another IC it can sample an astonishing 5 million cycles per second.

[Bob Davis] has been working on an Arduino based oscillscope for a while now. He keep squeezing more and more performance out of it. A previous version hit 3 megasamples using an AD775 chip. When he added a FIFO buffer chip he was able to squeeze 10-25 megasamples out of it… wow! Unfortunately the output tended to be glitchy.

This version gets rid of the AD775 in favor of a CA3306. Both are analog-to-digital converters but the new circuit is less complex and more reliable. It uses just three capacitors and an external clock to support the IC. Take a look at the video below to see how it performs. He’s outputting a graph of the samples on a small LCD screen. The best part is that since the extra chip is doing the sampling this can be ported to your microcontroller of choice.

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Two-way Bluetooth Communication Made Easy

July 8, 2013 by Mike Szczys 14 Comments

It’s hard to imagine an easier way to set up communications between an Android device and an Arduino using Bluetooth than by following this guide. In the center of the breadboard you can see the cheap and ubiquitous HC-05 Bluetooth module. Having picked up one of these ourselves we can attest that after opening the package and holding one in your hand you may be struck with a “where do I start?” conundrum. If you’ve got an Android handset and an Arduino you start right here, then methodically replace one side of the equation at a time until your own project has a Bluetooth component and you actually understand how it works.

Hardware for the project comes in a couple of parts. The Bluetooth module wants 3.3v logic levels so that is taken into account. The image above shows a buffer chip doing the conversion, but the Fritzing schematic on the post uses a voltage divider. The software end of things consists of an Arduino sketch and an Android app. Check out all the controls on that screen. With bi-directional communications and a slew of already-configured commands this should get you up and running quickly on pretty much any possible project.

One thing to note is that there are different firmwares for these HC-05 units. For more on that see this project.

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Rocketduino, For High-G, High Altitude Logging

July 7, 2013 by Brian Benchoff 17 Comments

rocketduino

Although the thrill of launching rockets is usually found in their safe decent back to Earth, eventually you’re going to want some data from your flight. Everything from barometric pressure, GPS logging, and acceleration data is a useful thing to have, especially if you’re trying to perfect your craft. [zortness] over on reddit created a data logging board created especially for amateur rocketry, a fabulous piece of work that stands up to the rigors of going very fast and very high.

The design of the board is a shield for the Arduino Mega and Due, and comes with enough sensors for over-analyzing any rocket flight. The GPS logs location and altitude at 66Hz, two accelerometers measure up to 55 G. Barometric, temperature, and compass sensors tell the ground station all the data they would need to know over a ZigBee 900MHz radio link.

Because this is an Arduino, setting up flight events such as deploying the main and drogue chutes are as easy as uploading a bit of code. [zortness] built this for a 4″ diameter rocket, but he says it might fit in a 3″ rocket. We just can’t wait to see some videos of it in action.

Turning A Router Into An Arduino Shield

July 6, 2013 by Brian Benchoff 15 Comments

[Dirk] had a problem: while he already had an Arduino with an Ethernet shield, he needed WiFi for an upcoming project. Running a Cat5 cable was out of the question, and a true Arduino WiFi shield is outrageously expensive. He did, however, have a WiFi router lying around, and decided it would make a perfect WiFi shield with just a little bit of cutting.

The router [Dirk] used was a TL-WR702N, a common router found in the parts bins of makers the world over. Inspiringly, the size of the router’s PCB was just larger than the space between the Arduino’s pin headers. Turning the router into a shield is simply a matter of scoring the edge of the board and gluing on a few pins for mechanical strength.

Power and ground lines were soldered between the pin headers and the router, while data is passed to the Arduino and Ethernet shield through a short cable. It may not look pretty, but if it works in a pinch we can’t complain.

LED Strip Pong As An Arduino Shield

July 6, 2013 by Mike Szczys 5 Comments

led-pong-strip

[Schuyler Sowa] has been hard at work on his own version of LED strip Pong. We’d say his work has really paid off. The game is robust and full of features.

Unlike the original Pong video game LED pong only has one axis on which the ball travels. The ball will bounce back if the button at the end of the strip is pressed when either of the last two LED pixels are illuminated. To add in a difficulty adjustment [Schuyler] included a poteniometer which alters the speed.

The game board is one meter of LED strip with individually addressable pixels. It cost a whopping $28 and was the second kind he tried after having trouble with the WS2801 based version (which often come as strings of lights). An Arduino board controls the game, with a shield made from protoboard to connect the components. In addition to the two user buttons — which were hacked out of a computer keyboard — you’ll notice a pair of seven segment displays acting as a scoreboard and an HD44780 character LCD rounding out the user interface.

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LegoDuino For Kid-friendly Microcontrollers

July 5, 2013 by Brian Benchoff 12 Comments

Lego

[J. Benschop] is teaching his nine-year-old son electronics by giving him a few wires, LEDs, and batteries. Eventually, the son looked over at his dad’s workbench and wondered what the little bug-shaped rectangles did. Microcontrollers and embedded programming are just a bit too advanced for someone who hasn’t hit a double-digit age, but [J] figured he could still have his son experience the awesomeness of programming electronics by building a custom electronic Lego microcontroller system.

This isn’t as complex as a Lego Mindstorms system. Really, it’s only an ATMega and a 2.4 GHz wireless transceiver. Still, that’s more than enough to add a few sensors and motor drivers, and an awesome introduction to electronics development. The enclosure for the LegoDuino is, of course, compatible with every Lego brick on the planet. It’s made from a 6×16 plate, three blocks high, with enough room for the electronics, three AA batteries, and the IO headers.

Programming an ATMega, even with the Arduino IDE, is a little beyond the capacity of [J. Benschop]’s nine-year-old son, so he made a few changes to the Minibloq programming environment to support the newly created LegoDuino. It’s a graphical programming language that kids of just about any age can pick up quickly, and with the included RF transceiver inside the ‘Duino, it can even be programmed wirelessly.

It’s an amazing piece of work, and much, much simpler than even the noob-friendly Lego Mindstorms. Not as powerful, though, but when you’re just teaching programming and electronics, you really don’t need much.

The 14th Game For The Nintendo Power Pad

July 3, 2013 by Brian Benchoff 7 Comments

[youtube=http://www.youtube.com/watch?v=6x23TWrInpI&w=580]

Released 25 years ago, the Nintendo Power Pad, a plastic mat that plugged into an NES, saw very limited success despite its prevalence in basements and attics. In total, only six games for the Power Pad were released in North America, and only 13 worldwide. The guys over at cyborgDino thought they should celebrate the sliver anniversary of the Power Pad by creating its 14th game, using an Arduino and a bit of playing around in Unity 3D.

The first order of business was to read the button inputs on the Power Pad. Like all NES peripherals, the Power Pad stores the state of its buttons in a shift register that can be easily read out with an Arduino. With a bit of help from the UnoJoy library, it was a relatively simple matter to make the Power Pad work as intended.

The video game cyborgDino created is called Axis. It’s a bit like a cross between Pong and a tower defense game; plant your feet on the right buttons, and a shield pops up, protecting your square in the middle of the screen from bouncing balls. It’s the 14th game ever created for the Power Pad, so that’s got to count for something.

Video of the game below.

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