Water tank level meter prevents overflow

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Most of the homes in the area where [Raikut] lives have tanks on the roof to hold water. Each is filled from a well using a pump, with gravity serving as a way to pressurize the home’s water supply. The system isn’t automatic and requires the home owner to manually switch the pump on and off. [Raikut] made this process a lot easier by designing an LED bar indicator to monitor the water level.

The sensor is very simple. Each LED is basically its own circuit controlled by a transistor and a few resistors. A 5V signal is fed from 7805 linear regulator into the tank. The base of each transitor is connected to an insulated wire, each extending different depths in the tank. As the water rises it completes the circuit, illuminating the LED.

[Raikut] is conservation minded and built a buzzer circuit which is activated by the LED indicating the highest water level. If someone walks away from the pump switch while it’s filling the alarm will sound as it gets to the top and they can turn it off before it wastes water.

[via Reddit]

Sump pump alarm sends text message as water rises

sump-pump-monitor

We’ve got some friends who have two sump pumps. One is a backup and sounds an alarm when it is switched on. But this only works as long as they’re home to hear it. [Felix Rusu] came up with a solution what will text him if the sump pump fails. This way he can head home, or call someone to check in on the problem if he’s away.

We saw a pretty complicated monitoring system back in January. This one uses a single ultrasonic rangefinder which we think is much simpler. It’s accurate to about 1cm and is simple to use — it’s very popular with the hobby electronics crowd which helps with price and availability of sample code. We hem and haw about the use of a Raspberry Pi board with the project. On the one hand it’s a cheap way to get the sensor on the network and provides the infrastructure you need to send any number of alerts. On the other hand, it’s a lot of power for this particular application. But we figure it can be extended to monitor other utilities in [Felix’s] home, like a sensor to alert him of a leaking water heater. And we think everyone can argue that a monitor like this is well worth the time and effort he spent to develop it.

NES annoyance timer makes no friends at your work

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Still trying to solidify that reputation as the office Grinch? This project will let everyone know you’re a complete jerk in no time. It’s called the 8-bit Annoying Person Remover. It detects when someone enters your office at which point it starts to play the Super Mario Bros. theme song while the display counts down 400 seconds. Just like in the game the music gets faster at the end and when it stops they know it’s time to get the heck out.

The hardware inside isn’t too complicated. An Arduino and a Wave shield do most of the work. The song played is stored on an SD card and can easily be changed. There’s a speaker mounted under the top heat vent of the enclosure. The device defaults to displaying the time of day, but monitors a motion sensor on one side to detect when someone comes through the door. This also works when someone leaves, cutting off the music and resetting the display. Don’t miss a video of it in action after the break.

It’s as if this was made specifically for the Comic Book Guy

Continue reading “NES annoyance timer makes no friends at your work”

Sunrise alarm clock mounted above the bed

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This sunrise alarm clock was made in a bit different form factor than we normally see. Instead of a box next to the bed it’s a bar above the headboard which slowly illuminates every morning. This was [Holly’s] first electronics project. She spent pretty much all summer working on it and accumulated a skill set that included designing for and operating the laser cutter and assembling and programming the electronics.

She didn’t start from square one. The hardware and programming were greatly simplified by the availability of RGB LED strips and the Monochron clock which drives them. [Holly] altered the code to bring up a blueish hue over a 35-minute time period. Since this will be used to wake her at 5:30am she was also obliged to include some backup sounds just in case. But after the project was finished and mounted she forgot to turn them on and was pleasantly surprised that the lights woke her up on time. The mounting bracket seen above uses t-slot rail with laser cut brackets to hold the half-cylinder shade for the sconce. The final product looks fantastic!

 

Sump pump monitor emails and raises alarm if water rises

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[Matt] literally finds himself in a sticky situation. There’s an oil slick in his sump well. These wells work in conjunction with drain tiles to pump water away from the foundation of a house. Unfortunately the tar that was used to waterproof the outside of his foundation is also washing into the sump and gumming up the works. The system he built will sound an audio alarm and send an email if something goes wrong with the sump pump.

He’s monitoring for two different issues. One technique uses a float valve to sense if the water is too high, signalling that the mechanism controlling the pump has malfunctioned. The other is a current monitor that senses if the sump pump has been running too long (caused by the sump’s water sensor getting stuck in the on position). The one thing he didn’t want to do is control the pump directly as a bug in his code will easily result in a flooded basement. We have the same concerns when considering building a DIY thermostat (an error there could mean frozen water pipes leading to flooding).

Directing an alarm system straight to the Internet

[Scott] has a pretty nice alarm system at his house – it will give the operator at his alarm company enough information to determine if it’s a fire alarm, burglary, or just a cat walking in front of a sensor. [Scott] wanted to cut out the middle man and receive notifications from his alarm system on his phone. He did just that, with the help of a trusty Arduino and the very cool Electric Imp.

[Scott]’s build began with an Arduino attach to a Raspi to monitor state changes in the alarm system. Because the designers of the alarm system included a very helpful four-wire bus between the alarm panels and the part connected to the phone line, [Scott] found it fairly easy to tap into these lines and read the current alarm status.

Dedicating a Raspberry Pi to the simple task of polling a few pins and sending data out over WiFi is a bit overkill, so [Scott] picked up an Electric Imp Arduino shield to transmit data over WiFi. We’ve played around with the Imp before, and [Scott] would be hard pressed to come up with a cleaner solution to putting his alarm monitor on the Internet.

Now [Scott] has a very tidy alarm monitor that sends updates straight to his cell phone, no middle man required. A very neat build, and an excellent use of a very cool WiFi device.

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.