Electronic Circuits and Diagram-Electronics Projects and Design

Digital tachometer using arduino plus speed control. Tachometer is a device used for measuring the number of revolutions of an object in a given interval of time. Usually it is expressed in revolutions per minute or RPM. Earlier tachometers purely mechanical where the revolution is transferred to the tachometer through mechanical coupling (cable or shaft) , the rpm is determined using a gear mechanism and it is displayed on a dial. With the advent of modern electronics, the tachometers have changed a lot. This article is about a contactless digital tachometer using arduino. The speed of the motor can be…

Interfacing  LCD to Arduino uno. LCD modules form a very important part in many arduino based embedded system designs. So the knowledge on interfacing LCD to arduino is very essential in designing  embedded systems. This article is about interfacing a 16×2 LCD  to Arduino. JHD162A is the LCD module used here. JHD162A is a 16×2 LCD module based on the HD44780 driver from Hitachi. The JHD162A has 16 pins and can be operated in 4-bit mode or 8-bit mode. Here we are using the LCD module in 4-bit mode. First, I will show you how to display plain text messages…

PWM motor speed control using Arduino. PWM or pulse width modulation is a very common method used for controlling the power across devices like motor, light etc. In PWM method the power across the load  is controlled by varying the duty cycle of the drive signal. More the duty cycle more power is delivered across the load and less the duty cycle, less power is delivered across the load. A hex keypad is used for controlling the speed. The speed can be varied in seven steps using the hex keypad. Arduino UNO is the type os arduino development board used…

Simple digital code lock using arduino. Digital code lock or digital combination lock are a type of  digital locks where a combination of digits/characters or both are used for unlocking the lock. This article is about a simple digital code lock using arduino. Here the code consists of a combination of  digits from 1 to 6. There are separate keys for locking and unlocking the system. The system can be unlocked by pressing the unlock button after entering the correct combination of digits. A hex key pad is used as the input device. Only the first two rows of key…

Interfacing hex keypad to arduino uno. This article is about how to interface a hex keypad to arduino. Hex keypad is a very important component in embedded systems and the typical applications are code locks, calculators, automation systems or simply any thing that requires a character  or numeric input. This project will display the pressed key in the serial monitor window of the arduino IDE. The same project can be modified to display the pressed key on 7-segment LED display or an LCD display. Before going into the details, have a look at the hex keypad. Hex keypad. Hex key…

Digital thermometer using arduino and LM35. This article is about a simple three digit digital thermometer using arduino. Range of this thermometer is from 0°C to 99.9°C. There is also a provision for displaying the temperature in °F scale. Three terminal analog temperature sensor LM35 is used as the sensor here. LM35 can measure temperatures between -55°C to +155°C. The supply voltage range is from 4V to 30V DC and the current drain is 60uA. The LM35 is available in TO-92 package and it is very easy to use. The output voltage of the arduino increases 10mV per °C rise…

Simple temperature logger using arduino (°C & °F). This project is about a simple USB temperature logging system using arduino uno and the serial monitor function in the arduino IDE. The system monitors the temperature every 2 seconds and shows it on the arduino serial monitor. The temperature is shown in °Celsius  and °Fahrenheit. The system is interfaced to the PC through the USB port. LM35 is used as the temperature sensor. LM35 is three terminal linear temperature sensor from National semiconductors. It can measure temperature from-55c to +150C. The voltage output of the LM35 increases 10mV per degree Celsius rise in temperature….

Ultrasonic range finder using arduino. Ultrasonic range finder using 8051 mictrocontroller has been already published by me in this website. This time it is an ultrasonic range finder using arduino. HC-SR04 ultrasonic range finder module is used as the sensor here. The display consists of a three digit multiplexed seven segment display. This range finder can measure up to 200 cm and has an accuracy of 1cm. There is an option for displaying the distance in inch also. Typical applications of this range finder are parking sensors, obstacle warning system, level controllers, terrain monitoring devices etc. Lets have a look…

0-5V voltmeter using arduino. This article is about a simple 3 digit voltmeter using arduino. The circuit can measure anything between 0 to 5V at an accuracy of 50mV. The circuit uses minimum number of external components and can be easily modified for different voltage ranges. The display device is a common anode multiplexed seven segment LED display module (Type No:E1-3056ASR1). Let’s have a look at the display device first. E1-3056ASR1. It is a low cost multiplexed 3 digit seven segment LED module of common anode type. Using such a multiplexed module instead of three separate display modules save a…

In this article we explain how to do PWM (Pulse Width Modulation) control using arduino. If you are new to electronics, we have a detailed article explaining pulse width modulation. We have explained PWM in this tutorial using 2 examples which will help you learn how to control LED brightness using PWM and how to control DC motor speed using PWM. PWM control using arduino. PWM control is a very commonly used method for controlling the power across loads. This method is very easy to implement and has high efficiency. PWM signal is essentially a high frequency square wave (…