Posts with «electronics» label
New Project: Make an EEG Beanie That Reads Your Mind
Time required: A weekend Cost: $100 — $130 Ever wanted to visualize your brain activity? Electroencephalography (EEG) uses electrodes placed against the scalp to detect the tiny electrical changes that occur when neurons fire. By amplifying these signals through a computer, you can observe brain activity in real-time. Using an […]
Adding WiFi and SMS to an Alarm System
[Don] wanted to bring his alarm system into the modern age. He figured that making it more connected would do the trick. Specifically, he wanted his alarm system to send him an SMS message whenever the alarm was tripped.
[Don] first had to figure out a way to trigger an event when the alarm sounds. He found a screw terminal that lead to the siren. When the alarm is tripped, this screw terminal outputs 12V to enable the siren. This would be a good place to monitor for an alarm trip.
[Don] is using an Arduino nano to monitor the alarm signal. This meant that the 12V signal needed to be stepped down. He ran it through a resistor and a Zener diode to lower the voltage to something the Arduino can handle. Once the Arduino detects a signal, it uses an ESP8266 WiFi module to send an email. The address [Don] used is the email-to-SMS address which results in a text message hitting his phone over the cell network.
The Arduino also needed power. [Don] found a screw terminal on the alarm system circuit board that provided a regulated 12V output. He ran this to another power regulator board to lower the voltage to a steady 5V. This provides just the amount of juice the Arduino needs to run, and it doesn’t rely on batteries. [Don] provides a good explanation of the system in the video below.
Filed under: Android Hacks, security hacks
Binary Clock Fit For Queen Elsa’s Ice palace
When life gives you lemons, you make lemonade. When life gives you freezing cold temperatures and a yard full of snow, you make binary clocks out of ice. At least that’s what [Dennis] does, anyway.
[Dennis’] clock is made from several cylindrical blocks of ice stacked on top of one another. There are six columns of ice blocks. The blocks were made by pouring water into empty margarine containers and freezing them. Once they were frozen, [Dennis] bore a 5/16″ hole into the bottom of each block to house an LED. Wires ran from the LEDs back into the drainage port of a cooler.
The cooler housed the main electronics. The LED controller board is of [Dennis’] own design. It contains six TLC59282 chips allowing for control of up to 96 LEDs. Each chip has its output lines running to two RJ45 connectors. [Dennis] couldn’t just use one because one of the eight wires in the connector was used as a common power line. The main CPU is an Arduino. It’s hooked up to a DS3234 Real Time Clock in order to keep accurate time. The oscillator monitors temperature in order to keep accurate time even in the dead of winter.
Filed under: Arduino Hacks, led hacks
An Illustrated Guide to Wearable Components
Bodies aren’t static, they don’t have straight lines, and after a while they tend to get dirty. So wearable systems embedded in garments and accessories have to be robust, flexible, and, ideally, washable (or at least removable). Here’s a look under the hood — or hoodie, as it were — at the main components of wearable devices.
Bluetooth Enabled Fuel Consumption Monitor
[Malebuffy] bought himself a used boat last year. Fuel isn’t exactly cheap where he lives, so he wanted a way to monitor his fuel consumption. He originally looked into purchasing a Flowscan off the shelf, but they were just too expensive. In the interest of saving money, [Malebuffy] decided to build his own version of the product instead.
To begin, [Malebuffy] knew he would need a way to display the fuel data once it was collected. His boat’s console didn’t have much room though, and cutting holes into his recently purchased boat didn’t sound like the best idea. He decided he could just use his smart phone to display the data instead. With that in mind, [Malebuffy] decided to use Bluetooth to transmit the data from the fuel sensors to his smart phone.
The system uses an older Arduino for the brain. The Arduino gets the fuel consumption readings from a Microstream OF05ZAT fuel flow sensor. The Arduino processes the data and then transmits it to a smart phone via a Bluetooth module. The whole circuit is powered from the boat battery using a DC adapter. The electronics are protected inside of a waterproof case.
[Malebuffy’s] custom Android apps are available for download from his website. He’s also made the Arduino code available in case any one wants to copy his design.
Filed under: Arduino Hacks
New Project: Wearable Temperature Sensors For Working in Extreme Cold
When working in extreme temperatures it is important to monitor your body temperature. In freezing weather, your fingers and toes get numb and you can develop frostbite without even noticing it. Likewise, if your core body temperature drops too low, you can start to start to suffer the effects of […]
Circular Knitic: An Open Hardware Knitting Machine
Artist duo Varvara Guljajeva & Mar Canet designed and built an open hardware automated knitting machine called Circular Knitic.
Losing to My High School Class a Big Win
Recently I switched careers from designing industrial food and dairy equipment to teaching industrial technology in a high school. While planning this move and taking night classes, I read quite a bit about authentic instruction where the students engage in real projects that end with something tangible and with real […]
Breathe New Life Into Payphones with Asterisk
Payphones used to be found on just about every street corner. They were a convenience, now replaced by the ubiquitous mobile phone. These machines were the stomping grounds for many early computer hackers, and as a result hold a place in hacker history. If you’ve ever wanted to re-live the good ol’ days, [hharte’s] project might be for you.
[hharte] has been working to make these old payphones useful again with some custom hardware and software. The project intends to be an interface between a payphone and an Asterisk PBX system. On the hardware side, the controller board is capable of switching various high voltage signals required for coin-line signaling. The controller uses a Teensy microcontroller to detect the hook status as well as to control the relays. The current firmware features are very basic, but functional.
[hharte] also wrote a custom AGI script for Asterisk. This script allows Asterisk to detect the 1700hz and 2200hz tones transmitted when coins are placed into the machine. The script is also in an early stage, but it will prompt for money and then place the call once 25 cents has been deposited. All of the schematics and code can be found on the project’s github page.
[Thanks mies]
Filed under: phone hacks
