There are a myriad of modern ways to lock and unlock doors. Keypads, Fingerprint scanners, smart card readers, to name just a few. Quite often, adding any of these methods to an old door may require replacing the existing locking mechanism. Donning his Bollé sunglasses allowed [Dheera] to come up with a slightly novel idea to unlock doors without having to change his door latch. Using simple, off the shelf hardware, a Smartwatch, some code crunching and a Google Now app, he was able to yell “OK Google, Open Sesame” at his Android Wear smartwatch to get his apartment  door to open up.

The hardware, in his own words, is trivial. An Arduino, an HC-05 bluetooth module and a servo. The servo is attached to his door latch using simple hardware that looks sourced from the closest hardware store. The code is split in to two parts. The HC-05 listens for a trigger signal, and informs the Arduino over serial. The Arduino in turn activates the servo to open the door. The other part is the Google Now app. Do note that the code, as he clearly points out, is “barebones”. If you really want to implement this technique, it would be wise to add in authentication to prevent all and sundry from opening up your apartment door and stealing your precious funky Sunglasses. Watch a video of how he put it all together after the break. And if you’re interested, here are a few other door lock hacks we’ve featured in the past.

Using an Arduino or Raspberry Pi to perform a task in the real world is certainly a project we’ve seen here before, and certainly most of these projects help to make up the nebulous “Internet of Things” that’s all the rage these days. Once in a while though, a project comes along that really catches our eye, as is the case with [Jamie’s] meticulously documented automatic garage door opener.

This garage door opener uses an ATMega328 to connect the internet to the garage door. A reed switch is installed which lets the device sense the position of the door, which is relayed back to the internet. [Jamie] wrote an Android app that can open and close the door and give the user the information on the door’s status. One really interesting feature is the ability to “crack” the garage door. This is done by triggering the garage door opener twice with a delay in between. From the video after the break we’d say this is how [Jamie’s] cat gets in and out.

We love seeing projects that are extremely well documented so that anyone who wants to make one can easily figure out how. Internet-connected garage door openers have been featured in other unique ways before too, but we’ve also seen ways to automatically open blinds or chicken coops!

[Oliver] is back with an update to his recent coffee maker hacks. His latest hack allowed him to add a coffee payment system to an off-the-shelf coffee maker without modifying the coffee maker itself. This project is an update to his previous adventures in coffee maker hacking which logged who was using up all of the coffee.

The payment system begins with an Arduino Uno clone inside of a small project enclosure. The Arduino communicates with the coffee maker via serial using the coffee maker’s service port. This port is easily available from outside the machine, so you won’t have to crack open the case and risk voiding your warranty.

The system also includes an RFID reader and a Bluetooth module. The RFID reader allows each user to have their own identification card. The user can swipe their card over the reader and the system knows how many credits are left in their account. If they have enough credit, the machine will pour a delicious cup of coffee.

The Arduino communicates to an Android phone using the Bluetooth module. [Oliver’s] Android app was built using MIT’s app inventor. It keeps track of the account credits and allows the user to add more. The system can currently keep track of up to forty accounts. [Oliver] also mentions that you can use any Bluetooth terminal program to control the system instead of a smart phone app.

Like many mobile gamers, [Daniel] has found himself caught up by the addictive “White Tiles” game. Rather than play the game himself though,  [Daniel] decided to write his own automatic White Tiles player. While this hack has been pulled off before, it’s never been well documented. [Daniel] used knowledge he gleaned on Hackaday and Hackaday.io to achieve his hack.

The basic problem is sensing white vs black tiles and activating the iPad’s capacitive touch screen. On the sensing end, [Daniel] could have used phototransistors, but it turned out that simple CdS cells, or photoresistors, were fast enough in this application. Activating the screen proved to be a bit harder. [Daniel] initially tried copper tape tied to transistors, but found they wouldn’t reliably trigger the screen. He switched over to relays, and that worked perfectly. We’re guessing that changing the wire length causes enough of a capacitance change to cause the screen to detect a touch.

The final result is a huge success, as [Daniel’s] Arduino-based player tears through the classic game in only 3.9 seconds! Nice work [Daniel]!

Click past the break to see [Daniel’s] device at work, and to see a video of him explaining his creation.

In the following 10-minute video, the Currah team is showing us all the details of Wood Lizzie, a project experimenting with Arduino Mega and Wi-Fi Shield, a very flexible steering system and the virtually unlimited control range afforded by WiFi and Internet Protocol:

The original plan was to construct one of the two-wheeled robots very popular with hobbyists but it was eventually decided that the resulting vehicle would be of very limited application and capable only of traversing smooth surfaces. However, note that the current design can be viewed as the drive of a two-wheeled robot coupled with a trailer by means of a 360 degree pivot. A slip ring capsule within the pivot enables the heavy battery and bulky control system to be separated from the drive and located on the trailer thereby distributing weight evenly between the four wheels.

DIY soap-carts were pretty common among kids in the first part of the 20th century and built from old pram wheels, scrap wood and, typically, soap boxes. They could provide a lot of fun for the family at very low cost and in recent years there’s a new interest in them especially to those appreciating their vintage look!

One more project, that shows breathtaking beauty of the FFT (Fast Fourier Transform). Once again, like in last 3D Ultrasonic Radar Project,    Arduino DUE was nominated to be Maestro, doing major part of the Digital Signal Processing in real time.  As you can see below, the hardware includes 4 “modules”:

1. Sensor board
2. Arduino DUE
3. Bluetooth shield
4. Android tablet.

Last two items aren’t strictly necessary. Alternative would be to connect TFT display directly to arduino, but I decided not to spend my time on re-inventing drawing-rendering software. Better to delegate all visualization stuff to the equipment that was  specifically design by big monsters in high tech industry.  I spend quite time digging into android graphics subject anyway, only hoping I can apply my knowledge somewhere else later on.

Sensor board holds 4 microphones from  SFE.  Plus a few decoupling components, capacitors and inductor in power line.

Software.

   Brief summary: Arduino sampling 4 analog inputs, close to 41 kHz,  x 4 = 164 ksps,  software library Radix4 posted on this blog was imported into project practically intact. DMA feature on Arduino DUE allows sampling rate up to 1 MSPS, and I already successfully tested its capability in 3D Radar project.  Having 2048 fft size, at the first processing stage  output there are 1024 bins 20 Hz each. Than, using arctangent LUT, phase of each bin is extracted.  Difference in phases two vertically position microphones gives Y component, and two horizontally spaced mic’s – X component. Sound source is localized with accuracy ~ 0.5 degree. Have to say, that on the lower frequency end, 100 Hz – 1 kHz , where wavelength is huge compare to spacing between two mic’s ( 3.4 meters at 100 Hz ), accuracy is deteriorating proportionally to wavelength.

Arduino is calculating data really fast, providing  X,  Y, and M  every 50 milliseconds. M – is for magnitude. Than, all this data stream flows to android over BT.  Everything else is obvious, watch the video.

Speaker outputs white noise, as for single tone (frequency) only one pixel would be visible on screen. Android software “colorized” picture based on a frequency, low range – starting from red, and up to violet on high end of the frequency band, through all 1024 color wheel possibilities.  You can see, that picture saturated with green and blue, and there is almost no red color. There are two things, first is a speaker, not performing well at low end. Second nuance is the fact, that low frequencies are not “grouped” so effectively, due to the localization error, what I tried to explain in a paragraph above. I created an option in the menu to select different types of colorization, based on a frequency or based on a magnitude. They are look pretty similar for white noise source, so there is only one video clip.

Have fun.

 Edited on 21 Oct. 2014:

 If you come across this page searching an old  “Localizator” project, published over 2 years ago, here is working material I was able to find:   Localizator.

One more project, that shows breathtaking beauty of the FFT (Fast Fourier Transform). Once again, like in last 3D Ultrasonic Radar Project,    Arduino DUE was nominated to be Maestro, doing major part of the Digital Signal Processing in real time.  As you can see below, the hardware includes 4 “modules”:

1. Sensor board
2. Arduino DUE
3. Bluetooth shield
4. Android tablet.

Last two items aren’t strictly necessary. Alternative would be to connect TFT display directly to arduino, but I decided not to spend my time on re-inventing drawing-rendering software. Better to delegate all visualization stuff to the equipment that was  specifically design by big monsters in high tech industry.  I spend quite time digging into android graphics subject anyway, only hoping I can apply my knowledge somewhere else later on.

Sensor board holds 4 microphones from  SFE.  Plus a few decoupling components, capacitors and inductor in power line.

Software.

   Brief summary: Arduino sampling 4 analog inputs, close to 41 kHz,  x 4 = 164 ksps,  software library Radix4 posted on this blog was imported into project practically intact. DMA feature on Arduino DUE allows sampling rate up to 1 MSPS, and I already successfully tested its capability in 3D Radar project.  Having 2048 fft size, at the first processing stage  output there are 1024 bins 20 Hz each. Than, using arctangent LUT, phase of each bin is extracted.  Difference in phases two vertically position microphones gives Y component, and two horizontally spaced mic’s – X component. Sound source is localized with accuracy ~ 0.5 degree. Have to say, that on the lower frequency end, 100 Hz – 1 kHz , where wavelength is huge compare to spacing between two mic’s ( 3.4 meters at 100 Hz ), accuracy is deteriorating proportionally to wavelength.

Arduino is calculating data really fast, providing  X,  Y, and M  every 50 milliseconds. M – is for magnitude. Than, all this data stream flows to android over BT.  Everything else is obvious, watch the video.

Speaker outputs white noise, as for single tone (frequency) only one pixel would be visible on screen. Android software “colorized” picture based on a frequency, low range – starting from red, and up to violet on high end of the frequency band, through all 1024 color wheel possibilities.  You can see, that picture saturated with green and blue, and there is almost no red color. There are two things, first is a speaker, not performing well at low end. Second nuance is the fact, that low frequencies are not “grouped” so effectively, due to the localization error, what I tried to explain in a paragraph above. I created an option in the menu to select different types of colorization, based on a frequency or based on a magnitude. They are look pretty similar for white noise source, so there is only one video clip.

Have fun.

This page is next level of Virtual Touch Screen project. 

Do you have this impression, like video I posted earlier was outdated? Software to draw a handwriting, mouse interface, etc. Wouldn’t it be nice to use a new era  technology? And here it is.

Technically, there are two hardware parts were added, to fully demonstrate extra ordinary sensitivity of the VTS project. First one is the BlueTooth module. And second is a tablet, running android. Device that I have, doesn’t support USB host mode (OTG), otherwise I may be fine w/o BT, just transfer a data over USB cable, as it was done in two previous demo video clips.  Have to say, it was not easy to represent 3D perspective on a flat screen, and picture below shows what I designed to complete a task:

Don’t think it requires a comments, the tricky part was to create an elliptical grid to show a distance. The number of circles is not limited to 2, I’d think about how to film next demo video, that ‘d show a “volume”.

Enjoy the movie:

This page is next level of Virtual Touch Screen project. 

First things is a distance, for virtual touch screen its less than 3 m, because the reflective area is too small. For radar (or sonar) its different, and the bigger size of object the stronger echo. Approximated range of detection the object as big as a wall, 30 meters.

Technically, there are two hardware parts were added, to fully demonstrate extra ordinary sensitivity of the VTS project. First one is the BlueTooth module. And second is a tablet, running android. Device that I have, doesn’t support USB host mode (OTG), otherwise I may be fine w/o BT, just transfer a data over USB cable, as it was done in two previous demo video clips.  Have to say, it was not easy to represent 3D perspective on a flat screen, and picture below shows what I designed to complete a task:

Don’t think it requires a comments, the tricky part was to create an elliptical grid to show a distance. The number of circles is not limited to 2, I’d think about how to film next demo video, that ‘d show a “volume”.

Enjoy the movie:

There are two apples, and arduino measure position in 3D space both of them. X, Y, and Z coordinates plus P – power of reflected ultrasonic wave used to draw circles, with different colors. You can see movement of the red circle on screen when first apples moves.

edited on 21-08-2014

After thinking awhile how to show a “volume” on a flat tablet screen, I decide to remove filtering stage in a software, when a bunch of consecutive “layers” were shown as one single ring (object) on a screen. Now each packet of data received from single “spherical” layer creates a circle. As always packet includes X, Y, Z, and P. To make an image “clear” there are two others filters left over in the processing algorithm. One is rejecting data below ( selectable in a menu ) power threshold, and another rejects anything thats located farther specific (again, selectable) distance. This is why in a video you can see only a ball, but not me – operator making a movie.

Here is how the ball looks like on radar screen:

And video:

That;s it for now.

Creators Mike Wakerly and Eric Webb have been at the smart keg game for a while. The two originally sold Kegbot as a do-it-yourself open-source project. They realized there was a market for a little easier option, and developed the plug-and-play version they're currently raising money for on Kickstarter. We recently met up with the team to see the device in action. %Gallery-slideshow164837%

Filed under: Household, Wireless, Alt

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