When designing or debugging an electrical or electronics device, it is very important to know the values of the components that have been used on board. With a multimeter most of the components can be easily measured and identified but most ordinary multimeters do not have options to measure inductors and capacitors as this is rarely needed. However, without capacitors there are literally no circuits while complex circuits may have inductors in them. A LCR (inductor-capacitor-resistor) measurement meter can be used to determine the aforementioned components but usually such meters are pretty expensive.Read more
Tag Archives: PIC18F452
Dilshan Jayakody’s new project is a digitally-controlled 2.1 channel audio amplifier based on the TDA7377 AF power amplifier and PIC18F452 microcontroller. The amplifier provides 2 × 6W + 20W audio output power, ±14dB bass and treble controls, fully configurable +35dB bass booster for sub-woofer and satellite speakers and loudness switch.
A tachometer is use to measure the rotations per minute (RPM) of a moving shaft or a motor. An example is a digital tachometer in a car that gives the RPM of the engine. This tutorial shows how to build a digital tachometer using a microcontroller and optical sensors.
The sensor unit consists of an IR LED that transmits infrared light and a photo diode that receives the light. This project uses a computer fan to demonstrate the technique. The fan is placed between the IR LED and the photo diode so that the blades of the moving fan interrupts the light received by the photo diode. Each interruption of the light gives a pulse that is counted by a PIC18F452 microcontroller. With a little math, the number of rotations per minute can be calculated. The result is displayed on a LCD screen. Read more
VGA stands for Video Graphics Array, which is a widely used analog interface between a computer and monitor that uses a 15-pin plug and socket. The VGA display requires accurate timing signals and synchronization. The goal of this project is to generate VGA signals using a PIC microcontroller to display characters, text and figures on a computer monitor.
It uses a PIC18F452 microcontroller running at 4 MHz external crystal to generate accurate timing signals to drive VGA pins. The software is written in assembly so that timing signals will be more accurate. The author also provides a brief introduction of VGA signals.