Home Automation Hack Controls Lights Based On Head Count

This home automation hardware turns on and off the lights based on room occupancy. The hack is an extension of an earlier version that was only a proof of concept. [RPisces] took the idea and made it into reality by mounting the sensor hardware in a doorway.

He prototyped the device using the MSP430 launchpad. It monitors a pair of IR distance sensors which record a change when something passes between them and the opposite side of the hallway. This is a good sensor choice as it only requires hardware on one side of the passageway. Because two of them are used, it’s quite simple to figure out if a person is entering or leaving the room based on which is tripped first.

In this case [RPisces] drives a relay to switch a lamp on and off. But it could be used for just about anything. We’d enjoy seeing it trigger an audio system like the one [Quinn’s] installing in every room.

Self Monitoring A Home Alarm System

[Lior] wanted to cancel the monitoring system for his home’s alarm, but he didn’t want to stop using the alarm all together. The trick is to rig up some way to monitor it himself. It would have been simple to have it just call him instead of the alarm company since the system just uses a telephone connection. But this would require that he have a land line for it to connect to, and when it calls him he would have no idea what part of the system had been set off. He developed a way to have the system text message him with all of the available details.

An Arduino controls the system, with a SIM900 GSM shield to hand the cell side of things. The board to the left emulates the standard telephone line, with an M8870 DTMF touch tone decoder to figure out what the alarm system is telling him. He also needed to implement touch tone generation to talk back to the system. His write-up includes links to other articles he posted about hardware, software, and protocol specifics.

Robot Bar Tender Records Wedding Guests Getting Drunk

Having an open bar usually means hiring at least one bar tender. But this hack does away with those labor costs (and someone to make sure your teenage cousins aren’t drinking) by putting a robot in charge of things. But the fun doesn’t stop there. One of the features of this bartender is that it records a 30 second video every time it dispenses a beverage. We’d image these get a bit funny as the night wears on before taking a dramatic turn into sadness.

The link above shares a ton of details on the device so make sure that you click-through the different pages in the navigation bar. The mechanical page shows off all of the effort that went into designing the machine in Solidworks. The ingredients start on the top layer in inverted bottles. Each feeds to a valve which has its own nozzle. Like a round version of the Inebriator, a glass is placed in a trolley at the bottom that pivots around the center of the machine. Once it gets back to the opening in the acrylic case you can grab your drink, give it a quick stir, and off you go.

Check out the video after the break to get a look at the user interface which includes that recorded video greeting for the happy couple.

Continue reading “Robot Bar Tender Records Wedding Guests Getting Drunk”

Hacking Dog Collars To Save Money On Batteries.

[Lou] sent in this amazingly simple hack that has been saving him money on special batteries for his dog collar. He uses an invisible fence system which gives the dog a shock if it passes beyond certain markers in his yard. The collars use special batteries so you’re not strapping multiple full sized cells to your dogs neck. This is especially necessary when you have a smaller dog that doesn’t weigh much to begin with.

What [Lou] found was that the $8 replacement batteries were simply a plastic shell on a battery he could buy for considerably less. All that was required were a few small cuts to the plastic casing to release the old battery, then he presses the new one into place. This tiny modification will be saving him a considerable amount since the unit burns through a battery in a few weeks.

Continue reading “Hacking Dog Collars To Save Money On Batteries.”

Building Your Own LED-based Home Lighting

We see LEDs used in all kinds of projects but rarely does someone build a home lighting system from scratch with them. [Paulo Oliveira] decided to give the idea a try, included a fading power supply for the LEDs which he built himself. Here you can see the installation at full brightness, but his controller also offers a single lower setting.

We saw [Sprite_TM] use an RGB LED strip to light up his living room. [Paulo] went with individual LED modules instead, all the same color. They are Cree XM-L power LEDs so some thought needs to be put into heat dissipation. All six are mounted along an aluminum strip which serves as the heat sink. They’re wired in series and powered by an old laptop power supply. A PIC 12F683 uses PWM to dim the string via a MOSFET.

The control system for the two brightness levels uses the wall switch. When turned on, the LEDs fade in to full brightness. If you turn the switch off and back on before they are all the way on, the dimmed setting takes over. This was complicated by the capacitance of the PSU but [Paulo] solved that by adding a power resistor.

Hacking Your Grill For Performance And Features

Summer is winding down, which means that sales will be beginning on grills at stores all over the place. For those that enjoy the outdoor cooking experience, a nice new grill is always tempting. If you’re anything like me though, it can be hard to justify the expense. All you need is some fire right? Well, not if you want to smoke foods, or do long controlled jobs, basically anything but quickly searing something.

[Joe Brown] over at Gizmodo found himself wanting to upgrade from simple coals/wood to something fancier, but really didn’t want to shell out the $2,000 that he found would be necessary to get the mic features he wanted. So, he set out to find a good platform to mod and added the features he wanted separately. The end result was a nicely performing out door cooking appliance that only cost him $540.

This hack is on the simpler side, but his modification really did add some great features. Many of you could build the addons from scratch, which makes me wonder, how would you improve a grill, dear Hackaday Reader?

Bluetooth Control In A Power Strip

[Mansour] had a ceramic space heater mounted near the ceiling of his room. Since heat rises this is not the best design. He upgraded to an infrared heater which works a lot better, but lacks the timer function he used on the old unit. His solution wasn’t just to add a timer. He ended up building a Bluetooth module into a power strip in order to control the device wirelessly. He ends up losing all but two outlets on the strip, but everything fits inside the original case so we think it’s a reasonable trade-off.

He uses relays on both the live and neutral wires to switch the two outlets. These are driven via MOSFETs to protect the ATmega168 which controls the board. The microcontroller and Bluetooth module both need a regulated DC power source, so he included a transformer and regulator in the mix. After the break you can see him demonstrating the system using two lamps. There’s even a terminal interface which lets you select different control commands by sending the appropriate character. This interface makes script a breeze.

At least this power strip doesn’t spy on you.

Continue reading “Bluetooth Control In A Power Strip”