Ben Krasnow developed this dispensing system that can measure out a desired mass of material via a dispensing valve controlled by a Parallax Propeller. He already had an American Weigh Scales miniPro-100, and decided to hack it so that the Propeller can discover how much mass is on the balance and regulate the dispensing valve […]
Category Archives: measurement
Better BBQ with Flyport and Cosm
Here’s a video demonstrating how to keep your BBQ under control using COSM and Flyport Wi-Fi: Michael Posavec, a strong supporter of openPicus, decided to hack his Maverick wireless BBQ thermometer adding Flyport Wi-Fi to make it Internet connected.
PIC16F74 – room thermostat with colour LCD
Room thermostat with PIC16F74, DS1820, and the Siemens M55 color LCD: The heart of the unit is an 8 bit PIC16F74 microcontroller from Microchip. It’s main task is to constantly monitor the room temperature trough a 1–wire digital thermometer IC, a DS1820 from Maxim, and to switch a relay on or off, that controls the […]
Precision voltage adapter for low voltage measurement
Kerry Wong shows how to make an adapter circuit for measuring very low voltages with a multimeter: I will show you a simple adapter circuit that can be used for precision voltage measurement down to the µV range. Using this circuit along with the current adapter circuit I discussed earlier you will be able to […]
USB Tester OLED backpack
William Garrido writes, “I released the USB Tester OLED Backpack today and thought it would be good for you guys to post up. It is an add on for the USB Tester for measuring voltage and current. With the OLED you don’t even need a DMM and can view the measurements on the OLED display […]
Speed of light measurement with the Analog Discovery scope
Measure the speed of light using the Analog Discovery. Digilent donated two Discoveries to the Open 7400 Competition this year, they were among the most popular prizes. The optical pulse response of the Discovery scope shows a reasonably clean shape with a fall time of ~ 30ns and minimal ringing. With such a clean response, […]
Arduino IR tachometer
Chris from Pyroelectro has posted this tutorial detailing the use of an IR transmitter and receiver break-beam pair to measure the speed of a fan. The IR components are used in conjunction with the Arduino UNO which processes the break-beam interruption counting with the result displayed on a 16×2 LCD display. You can get the […]
DEFCON 20: Hacking smart meters
At the recent DEFCON 20 conference in Las Vegas, Don C. Weber presented this talk on smart meter technology and security. The presentation deals with the optical port found on smart meters, and covers attacks from quick memory acquisition techniques to more complex hardware bus sniffing, as well as how authentication credentials are acquired. Finally, […]
Prop EKG: simple heart rhythm monitor using Parallax Propeller
RaysLogic has posted his plans for a Parallax Propeller based heart rate monitor. Dubbed the PropEKG, Ray’s design uses an AD627 instrument amplifier and TC1029 dual op amp. Data is processed by the Propeller and relayed to a Windows PC using a Parallax PropPlug (normally used for programming a Propeller chip.) The circuit is isolated […]
Simple DIY EMG sensors
Eric Schmiedl writes, “See the signals that make your muscles move… all it takes is an audio recorder and $10 worth of foil, coax, and duct tape. Oh, and some sugar syrup.” Eric constructed these DIY EMG sensors which he interfaced with an audio recorder to record his muscle activity.
Tutorial: Accurate Arduino ADC readings
The Hardware Hacking guys have posted this brief tutorial with tips on improving the accuracy of ADC reading with the Arduino. They endeavor to do this by measuring the internal 1.1V reference voltage (it is available for ATMega 168 and ATMega 328 only) and, then, by normalizing the ADC. Via the Arduino Blog.
PICAXE-08 raincounter
eclectica has posted a circuit for a PICAXE-enabled raincounter. The device employs a 1mm/pulse rain gauge to measure rainfall. Pulses from the gauge’s internal reed switch are read by the PICAXE-08 MCU, which in turn stores the running count in EEPROM and displays the resulting measurement on a serial LCD readout. While the exact type […]
O’Reilly video: Intro to Gestural Interfaces with the Microsoft Kinect
This webcast by Greg Borenstein presented by O’Reilly offers a solid introduction to building your own applications with the Microsoft Kinect. Beginners will find a wealth of information about the Kinect’s theory of operation and how to use the data it generates to work with Arduino, Processing and other frameworks. The importance of the calibration […]
Arduino lie detector
William Finucane of revoltlab posted this easy lie detector project on the Mad Science website. The hardware consists of nothing more than an Arduino, a 10K resistor, wire and some tin foil. (You didn’t use ALL your foil for your hat, did you?) The device operates on the galvanic skin response (GSR) principle and detects […]
SuperScope: circuit simulation through Arduino-Processing interface
Here’s a novel application. Supecapacitor has developed a circuit simulation project using Arduino-Processing. As he describes it: “SuperScope is a circuit simulator app for representing and calculating analog circuits. What’s so cool about SuperScope is the ability to actually import circuit components (via Arduino Serial) into the program where you can physically manipulate them. Arduino […]
ATMega88 based LCFesR meter
Ben Eishen sent in this link. He says, “I have been thinking about building an ESR meter, and this one looks like a winner.” The design is based on the ATMega88 and according to the designer, Dr. Le Hung, “The LCFesR 4.0 unit is a precise, wide range meter that can measure inductivity, capacity, frequency […]
Maker Shed pulse sensor
The folks over at MAKE have a pulse sensor which attaches to your fingertip or earlobe and measures minute changes in light from expansion of the capillary blood vessels to sense your heartbeat. Technical information is available here, including design files, sample code and schmetic. The device is licensed under the TAPR Open Hardware License. […]
DIY geomagnetic storm monitoring
With the recent increase in solar storm activity, Alexander Avtanski bring our attention to his DIY magnetometer project. The activity of the Sun varies on a cycle with a period of approximately 11 years. Periods of low solar activity are followed by a few years of sharply increased number of solar spots, flares, and coronal […]
Measuring temperature with Duinomite and KTY81
Olimex has posted this project for measuring temperature in range -55+150C for a solar water heater system. It uses the KTY81/110, a low cost PTC thermistor from NXP. The MCU board is the Duinomite we features in a previous post. Via the contact form.
Measuring hexacopter rotor speed with Logic Sniffer
Philip Peter has made a somewhat unconventional use of the Open Bench Logic Sniffer. Recently we suspected that one motor of our hexacopter had been damaged in a crash. Since removing the motor requires almost the complete disassembly of the copter I started thinking of ways to test the motor in place. In this article […]