Programming Micros With Impossibly Cheap Bluetooth Adapters

May 14, 2014 by Brian Benchoff 36 Comments

tooth

[Zenios] and [Raivis] are building a small balancing robot, and for communications to the outside world, they’re using a small, extremely cheap Bluetooth adapter. They figured uploading code to the microcontroller over Bluetooth would be a good idea, but their adapter, a cheap HC-06 module, had no way of resetting the microcontroller; it just provided Tx and Rx the serial port. They did notice a LED blinked when a device wasn’t connected to the adapter, so with a simple circuit they kludged a reset circuit where it wasn’t intended.

The small LED on the HC-06 module blinks when nothing is connected, and remains on when a connection is established. Figuring a new connection would be a good time to upload new code, the guys needed to design a circuit that would stay low when the LED was blinking, and switch to high when the LED was on.

A simple RC filter took care of the blinking LED, keeping the line low until a device connected. Bringing the logic level high when the LED stayed solid required digging through a part drawer, eventually finding an LM741 p differential amplifier.

After a few small changes to the bootloader, the guys had a reliable means of flashing new firmware without the need of programming adapters or wires draped over their workspace, all with a Bluetooth adapter that shouldn’t have this capability. Video below.

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Upgrade Your Garage Door With Arduino And RFID

May 13, 2014 by Rick Osgood 17 Comments

RFID Garage Door Opener

[Jason] really wanted to build an RFID controlled garage door opener and decided to turn to Arduino to get the job done. For someone who’s never worked with an Arduino before, he really seemed to know what he was doing.

The Arduino acts as the brains of the operation while an off-the-shelf NFC/RFID reader module is used to read the RFID tags. To add new keys to the system, [Jason] simply swipes his “master” RFID key. An indicator LED lights up and a piezo speaker beeps, letting you know that the system is ready to read a new key. Once the new key is read, the address is stored on an EEPROM. From that point forward the new key is permitted to activate the system.

Whenever a valid key is swiped, the Arduino triggers a relay which can then be used to control just about anything. In this case, [Jason] plans to use it to control his garage door. The system also has a few manual controls. First is the reset button. If this button is held down for two seconds, all of the keys from the EEPROM are erased. This button would obviously only be available to people who are already inside the garage. There is also a DIP switch that allows the user to select how long the relay circuit should remain open. This is configurable in increments of 100ms.

For now the circuit is wired up on a couple of breadboards, but it might be a good idea to use something more permanent. [Jason] could always take it a step further and learn to etch his own PCB’s. Or he could even design a board in Eagle CAD and order a real printed board. Don’t miss the video description of the RFID system below. Continue reading “Upgrade Your Garage Door With Arduino And RFID” →

DIY Arduino Cases You Never Knew Existed

May 9, 2014 by Rich Bremer 23 Comments

There are sure a lot of varieties of Arduinos out there but there may even be more of a variety when it comes to Arduino Cases. Let’s take the most popular Arduino form factor, the Uno. Below are a handful of unique cases for the Uno-sized boards.

by [Megaduty], Arduino Protection Box

We’ll call this one robust. Although it is 3D printed, its intent is to be extremely protective of the inhabitant. Some extra thought went into this case, no tools are needed! After the Arduino snaps into place, so does the cover. There is an access door to get the input/output wires to the free world. [Megaduty] suggests that this contains $0.10 of plastic. Not a bad deal.

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The Smallest ATtiny85 Based USB Board

May 7, 2014 by Nick Conn 41 Comments

Nanite 86

“Possibly the smallest ATtiny85 based ‘duino derivative”. Indeed! When Olimex announced the Olimexino 85s as the smallest Arduino ever, [Tim] took that as a challenge. His very small Arduino based USB devboard is quite a bit smaller than the Olimexino!

The Nanite 85 was carefully designed to be both small and functional. Not only is it 20% smaller than the Olimexino, but also sports a reset button! One of the coolest aspects of this design is that it has the same pinout and size as a DIP ATtiny85. This means that you can use the Nanite 85 for developing your code with the USB bootloader, and then you can directly replace it with a standard (pre-programmed) ATtiny85. The major downside to using this device over the aforementioned devices, is that it does not include a voltage regulator for powering the device via USB (or battery), the device is simply hooked directly to the 5V rail from the USB connector.

We can’t help but be impressed with this well-thought-out design. It is also easy to assemble since it uses larger surface mount components. If smaller components were used, even more features (such as a regulator) could be included. Do you have an even smaller USB Arduino? The race is on for the smallest Arduino ever!

Tell Time And Blink An LED On Your Wrist With WatchDuino

May 6, 2014 by Rich Bremer 23 Comments

Watchduino Open Source Watch

Is your hipster wrist having a hard time waiting for the debut of the iWatch? There’s a new open hardware/software project out that could help calm your nerves. The WatchDuino is exactly what it sounds like, an Arduino-based wrist watch.

The component list is short and inexpensive. The meat and potatoes consist of an ATMega328, crystal, Nokia LCD screen and LiPo battery. The USB-rechargeable battery lasts about a week before needing to be such. Besides presenting the Time and Date in both analog or digital formats (as you would expect) there is an alarm and timer. Additionally, there are 2 games, Pong and Snake. Any lack of features is made up for the fact that the software is open and can be modified and added to by the community. We’re sure the development of this watch will be quick and significant.

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Bacon Alarm Clock Won’t Burn Your House Down

May 5, 2014 by James Hobson 20 Comments

If you have trouble waking up in the morning then maybe this alarm clock is for you. A bacon-aroma-releasing alarm clock!

Fueled by her love of bacon, Instructable’s user [llopez2005] decided she wanted to try making an alarm clock that would actually get her out of bed, hungry, and ready for bacon. Instead of trying to design a clock that would actually cook bacon — which might be a bit dangerous — she’s found an extract of bacon aroma which she could slowly release instead.

The clock makes use of an Arduino Uno with a RTC shield as well as a LED array for the clock’s display. The “bacon” is actually made out of bake-able clay, which sits on top of unscented wax, infused with the bacon aroma oil. The bacon and “bacon grease” sit in a baby frying pan over top of a small heater element designed for warming candles. Before the alarm goes off, a SSR turns on the element which slowly melts some of the wax, releasing its ever so delicious scent.

What we really like about the clock is the level of detail she put into its appearance. The base is designed after a small wood burning stove they have in the house, and she’s even made a Plexiglas display case for the frying pan — with holes to let the aroma out though of course!

Go On A Power Trip With Powerduino

May 3, 2014 by Kristina Panos 10 Comments

powerduino Things don’t always run the way we want them to or operate at the ideal temperature out of the box. Instead of spending extra for power controls that may or may not meet your needs, wouldn’t it make more sense to dial in the ideal level from the source? That’s what [dekuNukem] had in mind when he decided to make Powerduino, an arduino-compatible programmable power strip.

With Powerduino, [dekuNukem] can control the electrical consumption of all kinds of things without ever worrying about the irreversible deadliness of mains voltage. It actually uses a Teensy 3.1 which can be programmed with the Arduino IDE through the micro USB connector. He’s really tricked it out to the point of putting Kill A Watt meters to shame. A wi-fi module lets him control any of the outlets from anywhere, and the RTC module lets him make customized schedules for them. Powerduino has an SD card slot for logging energy consumption, and a 20 x 4 LCD screen makes it easy to directly interface with the power strip.

The Powerduino code is up on GitHub, and [dekuNukem]’s walkthrough video is after the jump.

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