Archive for the ‘Arduino’ Category

LPG sensor using arduino

LPG sensor using arduino with alarm and cutoff. A simple LPG sensor using arduino is shown in this article. This circuit indicates the amount of LPG in the air. The circuit  sounds an alarm and trips a relay  when the concentration is above a predetermined level. MQ2 is the gas sensor used in this project. MQ2 is an SnO2 based gas sensor which can sense gases like methane, propane, butane, alcohol, smoke, hydrogen etc. Since LPG primarily contains propane and butane, MQ2 sensor can be used for sensing LPG. The figure below shows the schematic and arrangement of an MQ2…

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OhmMeter using Arduino – with Auto Ranging Feature

Auto ranging ohmmeter using arduino. This article is about a simple auto ranging ohmmeter using arduino. The measured resistance is displayed using a 16×2 LCD display. The circuit is sufficiently accurate and uses minimum number of external components possible. Before going into the details of this project, lets have a look at the basic resistance measurement method. Resistance measurement. The figure above shows the circuit diagram of a simple resistance measurement scheme. Rx is the resistance to be measured. R1 is the input resistance. i is the current passing through the loop and 5V is the supply voltage. To find…

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Water level controller using arduino

Arduino water level controller / indicator. This article is a about a fully functional water level controller using Arduino. The circuit displays the  level of water in the tank and switches the motor ON when the water level goes below  a predetermined level. The circuit automatically switches the motor OFF when the tank is full. The water level and other important data are displayed on a 16×2 LCD display. The circuit also monitors the level of water in the sump tank (source tank). If the level in side the sump tank is low, the motor will not be switched ON…

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Tachometer using arduino

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…

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Interfacing LCD to arduino

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…

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Motor speed control using arduino

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…

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Digital code lock using arduino

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…

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Interfacing hex keypad to arduino

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…

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Digital thermometer using arduino

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…

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Temperature logger using arduino

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….

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