Low-cost, Low-bandwidth Wireless Arduino To Android Communications

May 27, 2011 by Mike Nathan 22 Comments

android_nfc

[Joe] was experimenting with his Arduino when he started thinking about how he could get it to communicate wirelessly with his Android phone. Bluetooth is an option, but it requires some extra components, and Google’s ADK works as well – just not wirelessly.

Instead, he thought it would be neat to see if he could get the two devices to communicate with a simple magnetic coil. He constructed a small 1cm diameter coil, connecting it to the Arduino via a resistor and diode. Using the Android Tricorder app, he was able to locate his phone’s magnetometer, after which he ran some tests to narrow down the best sample rate and frequency range for communications.

To transfer data between the two devices, he had to bit bang the signal in software, since the Arduino’s UART has a lower limit far faster than the 7 bps data rate he was able to achieve with the magnetometer.

While his wireless Arduino to Android bridge isn’t likely to win any awards for throughput, it is a great proof of concept project. Be sure to check out the video below to see his “poor man’s NFC” in action.

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RF Control From Just About Any Device

February 20, 2011 by Mike Szczys 10 Comments

[Mirko] is working on a library that will allow you to add RF control to just about any device. The only requirement is that the device be capable of running a Linux kernel, and that it have a few GPIO pins available. One example is fairly straight forward, a Netgear router. Many, if not most routers run a Linux kernel natively and most have solder points on the board for unused IO pins so patching into the hardware is very straight forward. Less obvious and much more impressive is the hack seen in the image above. [Mirko] built an SD card adapter cable and uses the contacts in the card reader to bit bang four-wire SPI to communicate with that RF module.

Introduction To FTDI Bitbang Mode

September 22, 2009 by Phil Burgess 80 Comments

It was an interface that launched a thousand hacks. Near trivial to program, enough I/O lines for useful work, and sufficiently fast for a multitude of applications: homebrew logic analyzers, chip programmers, LCD interfaces and LED light shows, to name a few.

Today the parallel printer port is on the brink of extinction (and good riddance, some would say). Largely rendered obsolete by USB, few (if any) new peripherals even include a parallel connector, and today’s shrinking computers — nettops, netbooks, media center PCs — wouldn’t have space for it anyway. That’s great for tidy desks, but not so good if you enjoyed the dirt-cheap hacks that the legacy parallel port made possible.

Fear not, for there’s a viable USB alternative that can resurrect many of these classic hacks! And if you’ve done much work with Arduino, there’s a good chance it’s already lurking in your parts drawer.

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C64 USB Keyboard

July 6, 2009 by Steve Watkins 10 Comments

breadboard

[Maarten] told us about a C64 USB keyboard that was modified to be used as a standard input device. An interesting aspect of the project is the use of V-USB (formerly known as AVR-USB). V-USB is a software only approach to slow speed USB HID. In essence this is a two fold mod, The C64 keyboard is patched to a PC, and an off the shelf AVR is software-hacked to bit bang the USB communications. The author notes an initial problem with multiple key presses that was later corrected in the application. For the other side of the spectrum, we had covered the C64 twittering client, and a commodore 64 laptop.