Qrp Gaijin’s version of a dip meter to measure resonator Q: A highly-sensitive, narrow-band frequency-modulated dip meter offers a simple way to measure resonator Q. I have been working with an unusual dip meter circuit recently that has some interesting properties. The dip meter, also called a grid dip meter, is a simple homebrew instrument […]
Category Archives: measurement
Current meter based on ESP-12E and LTC4150
Victor Chew made a simple current meter based on ESP-12E, LTC-4150 and SSD1306 OLED module that measure the average current draw of a variable load accurately: The meter is powered by the micro-USB port on the ESP-12E. I soldered header pins onto the IN and OUT terminals of the LTC-4150. The whole idea is that […]
Low cost high accuracy STM32 FFT LCR meter
Adil Malik made a low cost FFT LCR meter with an STM32 MCU: The approach I took was a mixed signal one where a capable analog front end would be paired up with a beefy DSP processor to compute the Impedance. Most importantly, in this scheme, the DSP is responsible for discriminating the phase between […]
Tiny thermocouple thermometer
Johnson Davies built a tiny thermocouple thermometer based on an ATtiny85 measuring boiling water: This project describes a thermocouple thermometer, capable of measuring temperatures up to +1350°C, using just an ATtiny85 and an OLED display. More details on Technoblogy.
PLA dielectric strength measurement
Kerry Wong did some experiment measuring the dielectric breakdown voltage of PLA: In my previous post, I designed and 3D printed a high voltage connector for my Bertan 225-20R high voltage power supply. The silicone high voltage wire I ordered had finally arrived so I made a couple of cables using the connectors I printed. […]
CurrentRanger: auto-ranging current meter
An auto-ranging nanoAmp meter from LowPowerLab: CurrentRanger is a nanoAmp current meter featuring auto-ranging, uni/bi-directional modes, bluetooth data logging options and more. It is a highly hackable and affordable ultra low-burden-voltage ammeter, appropriate for hobby and professional use where capturing fast current transients and measurement precision are important. More details on LowPowerLab site. Check out […]
TRL measurements with homemade VNA and open source software
Henrik Forstén writes: I have been using the OSH Park’s 4 layer process a lot on my own projects. It has FR408 substrate that has better controlled permittivity and lower losses than ordinary FR-4 that other low cost PCB manufacturers use. In my opinion currently it is the best low cost process for making RF PCBs. […]
Stand-alone simulated analog meter
DuWayne S blogged about his stand alone simulated analog meter project: Thinking about what values I would like to display, I came up with three basic items. A S-meter when in receive, and a power output display when in transmit. In transmit, I would also like to have the capability of measuring VSWR. Thinking about […]
Debug SONOFF AC relay with a thermal camera
James Lewis shares his experience in debugging SONOFF AC relay with a thermal camera: The clever solution seemed to be clever, at least for a few minutes. Suddenly the light turned off. I thought maybe there was a timeout for the manual button. Annoying, but workable. The lamp remained off for about another 2 minutes when […]
Measuring USB power cable voltage drop with my DC load
Dr. Scott M. Baker published a new build: This started when one of my raspberry pi projects failed due to voltage drop on the USB power cable that I was using, so I set out with my power supply and DC Load to measure the voltage drop of various cables that I use in my […]
ATM90E36 Dev-kit for 3-phase AC metering
Tisham Dhar blogged about his ATM90E36 3-phase energy monitor project: After successfully building the single-phase energy monitor with the ATM90E26 there has been lots of interest in the 3-phase version. Being an open-hardware project, many people have created remixed and derived versions as well. After a while I started receiving requests to assist with the […]
Precision pressure meter with the Bus Pirate
Scott Harden has a nice build log on his precision pressure meter project: I just completed building a device capable of measuring temperature to one hundredth of a degree Celsius and pressure to one ten-thousandth of a PSI! This project is centered around an ICstation MS5611 temperature sensor breakout board which was small enough to […]
Quantifying cooling
Chris Palmer (a.k.a nophead) has designed and built this coolometer project to quantify the cooling effectiveness of various fan: I was wondering about how I was going to calibrate the airflow reading but then realised that the flow rate is not actually what I am interested in. It is the cooling effect the airflow has, which is […]
ESR measurement using multimeter and function generator
Kerry Wong has written an article discussing the measurement of capacitor ESR using a multimeter and a function generator: Capacitor ESR (Equivalent Series Resistance) measurement is very useful in diagnosing issues with power supplies. In linear power supplies, a high ESR filter capacitor may cause excessive ripple current on the voltage rails and can cause […]
DIY capacitance meter
Electro-Labs created new open source hardware project, a DIY capacitance meter: This is a capacitance meter which can measure capacitors rated from picofarads to millifarads. The principle of operation is simple. Just apply voltage to the capacitor and measure the elapsed time to charge it. The circuit is based on Atmega328P and it is Arduino […]
Using input impedance to measure current
Using input impedance to measure current, see the detailed blog post here from Sigzig: Input impedance on measurement equipment is usually kept as high as it can in an effort to prevent loading down the signals the equipment is measuring. For example most general purpose digital multimeters aim for an input impedance of at least […]
DIY compost sensor
Kinasmith wrote this instructable detailing how to build a compost temperature monitoring system, a web connected wireless sensor network: Why Measure the Temperature of Compost? “Composting is the biological decomposition of organic matter under aerobic conditions.” Micro-organisms consume organic material and oxygen and create heat as a waste product. By measuring this heat you can predict […]
Stand-alone inductance meter update
An update on Lukas’ stand-alone inductance meter project we covered previously: From a high-level point of view the new software is very similar to the Arduino sketch I wrote for the Inductance Meter Shield. If you look a bit closer, you’ll notice some differences for several reasons: This project uses an entirely different microcontroller: A PIC 16F1932 instead of […]
DIY active differential probe characterization
An 1GHz active differential probe project by Daniel Kramnik: This project was an ultra high input impedance (0.5pF||30MΩ or better) high bandwidth differential oscilloscope probe designed, built, and revised over the course of two weekends for the 2014 MakeMIT hardware hackathon. It can be built for about $30 in parts, plus the cost of etching or sending […]
Arduino-based inductance meter
Lukas of Soldernerd built a DIY Arduino-based inductance meter: I’ve just finished a little Arduino project. It’s a shield for the Arduino Uno that lets you measure inductance. This is a functionality that I found missing in just about any digital multi meter. Yes, there are specialized LCR meters that let you measure inductance but they typically […]