This post is about building a 3-digit countdown timer based on Arduino MEGA. Up/Down counter also available at this link. The timer will wait for 3-digit number to be entered via 4x3 keypad and then start counting down to zero ...

Digital Timer can be built by using PIC16F876A micro-controller and a few additional components. The schematic is similar to Fan Speed Monitor Design. 3x4 Keypad and 5V Relay were added as you can see from figure below. Only three 7-Segments ...

This is an upgrade to recently published Simple Digital Voltmeter.Few improvements were done to hardware and software.DVM operating range  was slightly increased up to 24 V Max, however the most significant change is that the code now uses full 10 bit of ...

In this post I'll show how you can drive 7 Segment LED display with PIC16F876A. Instead of using a dedicated IC’s like 4511 we’ll program the micro controller to convert  BCD input code 0 – 9 to a 7 Segment LED ...

This post is about building a Simple IR Proximity Sensor based on PIC16F877a micro controller. Usually these simple circuits are built using discrete components and include an OP AMP for comparing the photo diode voltage to a preset value. Current ...

Solar power mobile charger can be built by tweaking digital power supply schematic. The Software/Hardware stayed almost the same as the original circuit.Current design has the same overcurrent protection and output voltage can be changed by pressing SW1. Voltage and Current ...

LM35 is a temperature sensor that outputs a voltage proportional to the surrounding temperature in centigrade. In this post I’ll show how this device can be connected to Arduino MEGA board to build a thermometer that shows the current temperature ...

When working with multiple 7-Segment displays a multiplexing scheme is required in order to simplify the design and save Raspberry Pi I/O pins. Such implementations shown in this design. As can be seen from a schematic diagram 2 7-Segment displays ...

LM75A is a digital temperature sensor with built in analog to digital converter and I2C interface .It can provide an accurate temperature reading from -55 to +125 C. For similar design based on analog LM35 sensor click here. Also a ...

In this post I’m going to show you how to interface an I2C Real Time Clock – RTC with PIC microcontroller. Only a basic hardware configuration and a communication protocol are presented here. I’m planning to extend it to a ...