Panel meters in regulated power supplies are used to display electrical parameters like voltage and current. Presented here is a circuit to display DC voltage and current of power supplies, including DIY-type ones. Circuit and working Circuit diagram of the DC panel meter using Arduino is shown in Fig. 1. The circuit is built around Arduino Uno board (Board1), current sensor IC ACS712 (IC1), 16×2 LCD (LCD1) ...

With all the different ways capacitors are labeled, figuring out the values of your capacitors can be challenging. Especially if you don’t have a digital multi-meter to test them. In this tutorial, I’ll show you how to build three different capacitance meters using an Arduino and a couple resistors. After finishing this project, you’ll be able to measure all of your capacitors and label them for future refe ...

That first glimpse of a child in the womb as a black and white image on a screen is a thrilling moment for any parent-to-be, made possible by several hundred thousand dollars worth of precision medical instrumentation. This ultrasound machine cobbled together from eBay parts and modules is not that machine by a long shot, but it’s still a very cool project that actually gives a peek inside the skin. The ult ...

This project describes how to make a low-cost DC power meter that can be used for displaying Voltage, current, power and the running time of operation. This is useful and can be used as the display for your bench power supply too. This can be used in the display section of a 0-55 v battery charger, so the time elapsed gives you the actual time of charging the battery. The measurable voltage range of this ci ...

A digital soil moisture meter is used for indicating the water content of a given soil sample. [caption id="attachment_31551" align="alignright" width="300"] Soil moisture sensor head[/caption]   As crop production requires water at different stages and in different amounts, it is important to measure soil moisture from time to time to know its status. The digital soil moisture meter circuit presented ...

Precise measurement of line signal frequency is very important in many applications, especially in the management of power grid systems. Tasks like calibration of governors of engines that run generators in power plants need a resolution up to 0.01Hz. Frequency is also an important parameter in load sharing among several power plants in the grid. Presented here is a line frequency meter, that does it for yo ...

In this project I will show you how I combined an Arduino, an INA219 power monitor IC, an OLED LCD and a Micro SD Card PCB in order to create a power meter/logger that has more functions than the popular USB Power Meter. Let's get started! Step 1: Watch the Video! The video gives you a good overview on how to create your own power meter. In the next steps though I will present you some additional informatio ...

Presented here is a IoT enabled air pollution meter to monitor air quality on your smartphone using Blynk application and Arduino board. Blynk is an Internet of Things (IoT) platform to control Arduino, Raspberry Pi and the like over the Internet. In this project Blynk provides a digital dashboard on your smartphone that displays real-time air quality readings for the immediate surroundings. Blynk is not me ...

Three-fourths of the earth is water, out of which 97 per cent is saline (in oceans, seas and groundwater). The remaining 2.5 per cent to 2.75 per cent is fresh water , out of which 1.75 per cent to two per cent is frozen in glaciers, ice and snow. Fresh groundwater and soil moisture constitutes only 0.7 per cent to 0.8 per cent. Less than 0.01 per cent, available as surface water in lakes, swamps and rivers ...

From time to time, I see people trying to build an audio VU meter. In the analog era, that’s typically done with a voltage divider + a series of comparators; or using chips like LM3914/3915. Those chips are harder and harder to find, or you may need more resolution, or a different output profile. What to do? Modern MCUs offer an easy solution. their build-in ADC (10-bit or more) is more than enough for this ...

The app allows you to manage traditional air conditioners that are controlled through infrared remotes. Designed for the office environment, the app relies on the ambient brightness (measured by Tibbit #28) to determine whether the aircon should be running or not. In the office setting, no lights = no people = no need for the aircon to work. Air conditioning is a consumptive business while air conditioners ...

All embedded lovers are familiar with multimeter which a great tool to measure voltage, current, resistance etc. A multimeter can measure them easily. But sometimes we need to measure inductance and capacitance which is not possible with a normal multimeter. There are some special multimeters that can measure inductance and capacitance but they are costly. We already built Frequency Meter, Capacitance Meter ...