We are now going to talk about one small cheap sensor that we call DHT11, and we can use that for measuring humidity and also temperature. You can see that many Arduino people like this sensor because it is very simple and also very low cost, so anybody can buy and try. The DHT11 can […]
Sensors and Detectors
Alcohol Detector Meter Circuit using MQ-3 Sensor Module
An alcohol detector is a sensitive device which is able to detect the presence of alcohol molecules or any similar volatile inflammable element in the air and convert it into equivalent level of electrical output. The simple alcohol detector circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such […]
Fence Charger Animal Contact Detector Circuit with Audible Buzzer
In one of my electric fence charger articles, one reader asked me something interesting. He wanted to know whether a buzzer could be made to sound whenever an animal touches the fence. At first I was thinking about a current sensing method because that looks like the obvious way. But after looking at how electric […]
How to Connect a TSOP1738 IR Sensor
TSOP17XX series devices are advanced infrared sensors having a specified center frequency of operation which makes their detection extremely reliable and foolproof. In this post I have explained how to connect a TSOP series infrared sensor and use it for a specified IR remote control operations. TSOP IR Sensor Specifications A TSOP series of IR […]
Photodiode, Phototransistor – Working and Application Circuits
Photodiodes and phototransistors are semiconductor devices which have their p-n semiconductor junction exposed to light through a transparent cover, so that external light can react and force an electrical conduction through the junction. How Photodiodes Work A photodiode is just like a regular semiconductor diode (example 1N4148) consisting of a p-n junction, but it has […]
INA219 Current Sensor Circuit Diagram and Datasheet
In this post we are going to understand this sensor called INA219, and this one is like a full smart sensor. It not only tells how much current is flowing but also tells voltage, and also calculates power, all in digital form. That means it talks with microcontroller through I2C lines. It is like an […]





