Most of embedded microcontrollers contain watchdog timer. Watchdog variable timer is literally a „watchdog“. Watchdog timer continuously inspects the program float. Basically if microcontroller program hangs, then watchdog timer resets it and brings embedded system back to life.
The idea is very simple. Lets say, you know, that your program has to be executed during 20ms. [...]

Reading of datasheets is or should be an important part of designing electronic devices. Reading datasheets is necessary in writing device requirements, planning budget, and selecting suitable components. Datasheets of each component may be found in manufacturer’s website.
Once you’ve selected suitable component be sure that you read the datasheet and understand everything in it. Otherwise [...]

In electronic circuit drawings there are two types of objects: component symbols and nets. Nets represent wires connecting the components – which represent physical devices. In a example bellow we see component type MAX3232. U2 is a reference label of component. Electronic component usually has pins. Pins always have their numbers starting from 1. Pins [...]

This is small comparison made between three types of motors: DC motors and stepper motors. Let’s see what are their cons and pros:

Stepper motors doesn’t require feedback to determine position. The position is determined by microcontroller by sending pulses to stepper motor;
When [...]

Serial Peripheral Interface is a simple interface which enables to communicate microcontroller and peripheral chips or intercommunicate between two or more microcontrollers. Serial Peripheral Interface bus sometimes called four wire interface may be used to interface such chips or devices like: LCD, sensors, memories, ADC, RTC. The range of usage is huge.
SPI Bus uses [...]

This is most common voltage regulator that is still used in embedded designs. LM7805 voltage regulator is a linear regulator made by several manufacturers like Fairchild, or ST Microelectronics. They can come in several types of packages. For output current up to 1A there may be two types of packages: TO-220 (vertical) and D-PAK (horizontal).

With [...]

Timing diagrams are the main key in understanding digital systems. Timing diagrams explain digital circuitry functioning during time flow. Timing diagrams help to understand how digital circuits or sub circuits should work or fit in to larger circuit system. So learning how to read Timing diagrams may increase your work with digital systems and integrate [...]

In general there are two ways to control DC motor speed: by varying supply voltage and pulse width modulation (PWM). First control method is not convenient especially in digital systems. It requires analog circuitry and so on. Second motor speed control method is very convenient for digital systems, because all control is made using only [...]

When LCD is working in 4 bit mode, then data has to be sent by nibbles – portions of 4 bits. Just remember that first goes high nibble then follows lower one. Each nibble has to be strobed with control signal E separately. Following list is describing how to start LCD in 4 bit mode:

Wait [...]

Power sources for AVR are very important part in projects. Avery circuit has to be powered from some source like battery or from AC adapter 110V/220V. Using batteries is more convenient way to power the microcontroller projects as the circuits are simpler and constructed devices become portable.
There are many types of batteries in shapes and [...]