Power saving sleep mode is added in the chip that generates a low current power down mode. The sleep mode can be removed using an interrupt, watchdog timer or external reset.
This feature is included in most of the PIC controllers that resets the controller when it is powered on. If there comes a glitch in the chip, powering on the device will exclude it from the loop of any malfunctioning in the device. Registers play a vital role in the controller.
They are the data holding places in the processor of the controller. A single register can hold storage address, instruction and any kind of data ranging from bit sequence to individual characters. Both are used for holding specific data. General purpose registers are used for storing any modified or random value in the processor. While Special function registers monitor and control the various aspect of the processor functions. Each bank comes with bytes of memory space where first 12 locations are allocated to special function registers while remaining are reserved for general purpose registers that are used as static RAM.
This register is mainly used for switching between the banks. Setting fifth bit of this register indicates we targeting bank 1 while resetting it will indicate we are targeting bank 0.
This register decides the possibility if the Port A pins are used as input or output. The value 1 indicates output and value 0 indicates input. W Register. It is accessible by a program and is not a part of any register bank. Playing with circuits seems quite daunting for some people. Watching other people proceed and developing many projects with the same interest as yours put you in high inferiority complex. But if you do not want to spend much for your project, a single chip pic micro would be perfect for getting you started.
PIC18F is a readily available, amazing, and calm competent microcontroller which can help you to add some logic and Intel to your projects. PIC16F84A microcontroller is a very famous pic microcontroller. You may like to check pic microcontroller tutorials.
This is an 18 pin IC, the description of each pin are given below:. These 13 GPIO pins can be independently configured either as digital input or as digital output.
Also, each pin can either supply or can absorb a maximum of 25mA current per pin. So, accordingly, every pin can drive a LED easily but cannot drive any dc motor or relays. Because, current requirement for LED is generally less than 10mA and dc motor requires greater than 25mA. If you want to interface relay or dc motor, you have to use current driver ICs. Like motor driver IC to interface motor and relay driver IC to interface single of multiple relays.
Each of these pins source and sinks 25mA current. With little careful, you can program the microcontroller deprived of eliminating it from the target board for example in-circuit. It contains 64 bytes memory that is mainly used to store data and 1K program memory specifies the capacity of code you can burn inside.
Watchdog timer: This microcontroller has built-in Watchdog timer. There is an internal timer located under the chip. You can make this timer enable or disable by programming.
The timer is mainly used to rest the microcontroller when the program goes wrong or it may enter to the infinite loop. Registers: There are two types of registers which are as follow here. You can name yours anything and save it in your preferred location. Your project will be saved as a folder with the Extension. Click Finish. Step 7: Your project has been created.
The left most window will show the project name, click on the project name to view the directories inside it. In order to start programming we need to add a C Main file, inside our Source file directory. Step 8: The following dialog box appears. Enter a name for the C-file. But you can name it anything. Then click Finish.
Before you start program any Microcontroller you have to know about its configuration registers. Without setting the configuration registers of a microcontroller correctly, your program may be correct yet the device may not still function as required. Consider the following examples. So, for our project, we are going to use a 10Mhz oscillator so we will select HS using the following code:. The Watchdog Timer is a free running, on-chip RC oscillator which does not require any external components.
If the timer is not cleared in our software coding then the microcontroller will reset upon every WDT timer overflow. The WDT can be permanently disabled by clearing configuration bit.
We are not using WDT in our program so let us disable it by the following:. The Power-up Timer operates on an internal RC oscillator. A configuration bit is provided to enable or disable the PWRT.
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