- PIC Microcontroller was manufactured by General instrument’s Microelectronics.
- It was initially named as Peripheral Interface Controller and was later known a Programmable intelligent computer.
- They were ready to be used by the year of 1976 and was went on to sell more than 10 billion units by 2014.
- They are employed in a wide variety of embedded systems in the modern world today and very popular amongst hobbyists and industrialists.
- Earlier versions of PIC unfortunately had ROM and EPROM only.
- PIC16F887A employs the Harvard architecture.
- Lack of external memory interface.
- Watchdog timer
- Different RC oscillator configurations
- Smaller instruction set
- Reduced instruction set.
- Inexpensive microcontrollers.
- Supports different protocols I2C,UART, SPI.
- Just one accumulator.
- Register bank switching required to access complete RAM of devices.
PROTEUS DIAGRAM FOR INTERFACING 8 LEDs with PIC16F887A
EXPLANATION OF DIAGRAM(PROTEUS):
- Here pins 13 and 14 of the PIC Microcontroller are connected to an RC oscillator via two capacitors each measuring 22PF.
- The MCLR pin 1 of the microcontroller is connected to a resistance of 10K Ohm.
C programming code:
TRISB.F0 = 0; //Makes PORTB0 or RB0 Output Pin
while(1) //Infinite Loop
PORTB.F0 = 1; //LED ON// RBO pin of port b is toggled
Delay_ms(1000); //1 Second Delay
PORTB.F0 = 0; //LED OFF
Delay_ms(1000); //1 Second Delay is given after each blink of led
WORKING VIDEO LINK:
Linux as a free software, get a great deal of development, embedded systems and Linux combination is increasingly being optimistic. Linux has its own set of tool chain, easy to create your own embedded system development environment and cross-operating environment, and embedded system development across the simulation tools obstacles. Linux kernel has a small, high efficiency, open source.
Linux device drivers can be either built into the kernel itself, or can be built as modules. When built into the kernel, the device driver is always loaded and ready to be used. If built as a module, the device driver will have to be installed before attempting to use the device. This can be done automatically using scripts, manually from the command line, or the kernel can automatically load modules as needed.
Embedded Linux is increasingly popular Linux operating system modified so that it can be cut in the embedded computer system running an embedded Linux operating system on the Internet not only inherited the unlimited resources but also has embedded the open source operating system characteristics.
Advantages of linux as an embedded system
Linux can be applied to a variety of hardware platforms. Linux uses a unified framework to manage the hardware, from one hardware platform to another hardware platform changes and the upper application-independent.
Linux can be freely configured, does not require any license or business relationship, the source code is freely available. This makes the use of Linux as the operating system does not have any copyright disputes, which will save a lot of development costs.
Linux is similar to kernel-based, with full memory access control, supports a large number of hardware and other characteristics of a common operating system. All of its open source program, anyone can modify and GUN General Public License issued under. In this way, developers can customize the operating system to meet their special needs.
Linux users are familiar with the complete development tools, almost all Unix systems applications have been ported to Linux. Linux also provides a powerful networking feature, a variety of optional window manager (X Windows).
The linux powerful language compiler GCC, C++, etc. can also be very easy to get, not only sophisticated, but easy to use.
The advantages of embedded Linux over embedded operating systems include multiple suppliers for software, development and support; no royalties or licensing fees; a stable kernel; the ability to read, modify and redistribute the source code. The disadvantages is a comparatively large memory footprint complexities of user mode and kernel mode memory access.
Now lets see in which all embedded system linex is used.
Nspire CAS CX Calculator: This is a simple calculator yet powerful. It is ia an ARM based graph calculator that is powered by Linux.
Linux has proved itself to be a more stable operating environment; its functions are stable enough that seldom does one encounter screen freezes, repeated boot-ups, etc.
The Linux OS handles different functions through the kernel in a different way compared to Windows. This creates a faster system that is even closer to UNIX (it actual parent system).
Smart Tv: Ubuntu is powering Smart Tv.
Different versions of Linux
Blue Cat Linux at http://www.lynuxworks.com,
Hard Hat Linux at http://www.mvista.com,
RT-Linux at http://www.rtlinux.com,
ThinLinux at http://www.thinlinux.org,
White Dwarf Linux at http://www.emjembedded.com/linux/dimmpc.html, and
Linux Embedded at http://linux-embedded.com.
Let’s see some of the abbreviations which are used in embedded c.
We have different abbreviation for embedded in different fields.
EOC-Embedded Operations Channel
E.S -Embedded Solutions
eVB – EMbedded Visual Basic
ES – Embedded System Technology
EC -Embedded Connectivity
EL-Embedded Linux Linux
EWS-Embedded Web Server
EP-Embedded Passives Capacitor
EP -Embedded Profile