Introduction to PIC16F887
Hey Guys! Hope you are doing well. This is a platform where we keep you updated with valuable information so you keep coming back for what we have to offer. Today, I'll uncover the details on the
Introduction to PIC16F887. It is a 40-pin PIC microcontroller, introduced by Microchip, and is a successor of PIC16F877A.
Microcontrollers have revitalized the technology by providing a flawless interface and an ability to perform numbers of functions on a single chip. Gone are days, when you had to rely on external components to develop your projects which might be time-consuming, covered more space, and required a number of prior skills before making your project in real time. Microcontrollers have made things easy by covering each and every aspect of the projects that are directly or remotely related to automation.
In this tutorial, I'll discuss each and everything related to PIC16F887 including its main features, working, pinout and applications. Let's jump right in and nail down everything you need to know.
Introduction to PIC16F887
- PIC16F887 is a 40-pin (for PDIP package) and 8-bit CMOS PIC Microcontroller that comes with nanoWatt technology. Economical price and user-friendly architecture make this device easy to use and easy to configure.
- It is available in three packages known as PDIP, QFN, and TQFP. The first one comes with a 40-pin layout design while remaining two contains 44 pins on each layout.
- This PIC version, like other models in the PIC community, contains everything that is required to make an embedded system and drive automation.
- The PIC16F887 incorporates 256 bytes of EEPROM data memory, 368 bytes of RAM, and program memory of 8K.
- Apart from self-programming capability, it also contains 2 Comparators,10-bit Analog-to-Digital (A/D) converter with 14 channels, and capture, compare and PWM functions.
- The asynchronous serial port is added on the chip that can be configured both ways i.e. the 2-wire Inter-Integrated Circuit (I²C™) Bus or 3-wire Serial Peripheral Interface (SPI™)
- The Enhanced Universal Asynchronous Receiver Transmitter (EUSART) feature makes this chip compatible with the devices where serial communication is an integral part of the project.
- The functions that make this device unique in terms of ease of use include
- Power-Saving Sleep mode
- Industrial and Extended Temperature range
- Wide operating voltage range (2.0V-5.5V)
- SR Latch mode
- Power-up Timer (PWRT) and Oscillator Start-up Timer (OST)
- Power-on Reset (POR)
- Ultra-Low-Power Wake-up (ULPWU)
- Multiplexed Master Clear with pull-up/input pin
- Individually programmable weak pull-ups
- Brown-out Reset (BOR) with software control option
- Enhanced low-current Watchdog Timer (WDT)
- Needless to say, this PIC version is an ideal choice to drive A/D conversion in automotive, consumer, and industrial applications.
1. PIC16F887 Pinout & Description
Getting a hold of Pinout and Pin descriptions is mandatory to check the working of each pin on this tiny chip. If you are a newbie or an expert, you need to know the function associated with each pin for a better understanding of the chip.
Pinout
The following figure shows the complete pinout of all three packages called PDIP, QFN, and TQFP.
- As described earlier, the PDIP package contains 40-pin while other two come with 44 pins.
Pin Description
PIC16F887 is widely used in many electronic applications. Some pins in the controller are capable of doing more than one functions that allow us to use the pin according to the needs and demands of the project.
I have listed the function of each pin in the following table.
| Pin# |
Pin Name |
Pin Description |
| 2 |
RA0
AN0/ULPWU
C12IN0- |
Digital I/O Pin
Analog Input 0 Pin
Comparator |
| 3 |
RA1
AN1/ULPWU
C12IN1- |
Digital I/O Pin
Analog Input 1 Pin
Comparator |
| 4 |
RA2
AN2
C2IN+
VREF-/CVREF |
Digital I/O Pin
Analog Input 2 Pin
Comparator
ADC Reference Input Voltage (low) |
| 5 |
RA3
AN3
C1IN+
VREF+
|
Digital I/O Pin
Analog Input 3 Pin
Comparator
ADC Reference Input Voltage (high) |
| 6 |
RA4
C1OUT
T0CKI |
Digital I/O Pin
Comparator
External clock input for Timer0 |
| 7 |
RA5
AN4
C2OUT
SS |
Digital I/O Pin
Analog Input 4 Pin
Comparator
Slave Select input for SPI |
| 33 |
RB0
AN12
IOC/INT |
Digital I/O Pin
Analog Pin
Interrupt-on-change |
| 34 |
RB1
AN10
C12IN3-
IOC |
Digital I/O Pin
Analog Pin
Comparator
Interrupt-on-change |
| 35 |
RB2
AN8
IOC |
Digital I/O Pin
Analog Pin
Interrupt-on-change |
| 36 |
RB3
AN9
C12IN2-
IOC
PGM |
Digital I/O Pin
Analog Pin
Comparator
Interrupt-on-change
Basic |
| 37 |
RB4
AN11
IOC |
Digital I/O Pin
Analog Pin
Interrupt-on-change |
| 38 |
RB5
AN13
T1G
IOC |
Digital I/O Pin
Analog Pin
Timer
Interrupt-on-change |
| 39 |
RB6
IOC
ICSPCLK |
Digital I/O Pin
Interrupt-on-change pin
Basic |
| 40 |
RB7
IOC
ICSPDAT
|
Digital I/O Pin
Interrupt-on-change pin
Basic |
| 15 |
RC0
T1OSO/T1CKI |
Digital I/O Pin
Timer |
| 16 |
RC1
T1OSI
CCP2 |
Digital I/O Pin
Timer
ECCP |
| 17 |
RC2
CCP1/P1A |
Digital I/O Pin
ECCP |
| 18 |
RC3
SCK/SCL |
Digital I/O Pin
MSSP |
| 23 |
RC5/SDO
RC5
SDO |
Digital I/O Pin
SPI Data-Out Pin |
| 24 |
RC5
SD0 |
Digital I/O Pin
MSSP |
| 25 |
RC6
TX/CK |
Digital I/O Pin
USART |
| 26 |
RC7
RX/DT |
Digital I/O Pin
USART |
| 19 |
RD0 |
Digital I/O Pin |
| 20 |
RD1 |
Digital I/O Pin |
| 21 |
RD2 |
Digital I/O Pin |
| 22 |
RD3 |
Digital I/O Pin |
| 27 |
RD4 |
Digital I/O Pin |
| 28 |
RD5
P1B |
Digital I/O Pin
ECCP |
| 29 |
RD6
P1C |
Digital I/O Pin
ECCP |
| 30 |
RD7
P1D |
Digital I/O Pin
ECCP |
| 8 |
RE0
AN5 |
Digital I/O Pin
Analog Pin |
| 9 |
RE1
AN6 |
Digital I/O Pin
Analog Pin |
| 10 |
RE2
AN7 |
Digital I/O Pin
Analog Pin |
| 13 |
RA7
OSC1
CLKIN |
Crystal Oscillator Input Pin |
| 14 |
RA6
OSC2
CLKOUT
|
Crystal Oscillator Output Pin |
| 1 |
RE3
MCLR
VPP |
ICSP Programming Enable Pin
Master Clear Active Low Reset Pin |
| 11,32 |
VDD |
Voltage Supply Pin |
| 12,31 |
VSS |
Ground Pin |
2. PIC16F887 Features
You can anticipate the nature of any device by looking at its main features. Following table shows the complete features of PIC16F887.
| PIC16F887 Features |
| No. of Pins |
40 |
| CPU |
8-Bit PIC |
| Operating Voltage |
2 to 5.5 V |
| Program Memory |
8K |
| Program Memory (Instructions) |
8192 |
| RAM |
368 Bytes |
| EEPROM |
256 Bytes |
| ADC |
10-Bit |
| I/O Ports (5)
I/O Pins |
A,B,C,D,E
35 |
| Packages |
40-pin PDIP
44-pin QFN
44-pin TQFP |
| External Oscillator |
up to 20 MHz |
| Timer (3) |
16-Bit Timer (1)
8-Bit Timer (2) |
| USART Protocol |
1 |
| I2C Protocol |
Yes |
| SPI Protocol |
Yes |
| Brown-out Reset |
Yes |
| Watchdog Timer |
Yes |
| Comparators |
2 |
| Master Synchronous Serial Port (MSSP) module |
1 |
| Capture/Compare/PWM |
16bit/16bit/10bit |
| Power Saving Sleep Mode |
Yes |
| Selectable Oscillator Option |
Yes |
| Operating Current |
11uA at 32 kHz, 2.0 V
220uA at 4 MHz, 2.0 V |
| Temperature Range |
-40 to 125 |
| Oscillator Start-up Timer |
Yes |
- Checking main features before purchasing of the controller will help you analyze and develop your required project.
- Power on reset and selectable oscillator options are some unique features included in the chip.
3. PIC16F887 Functions
This PIC model performs many functions that are quite similar to the function in other controllers of the PIC community. Following are the main functions of PIC16F887.
Timer
PIC16F887 contains one 16-bit timer and two 8-bit timers that can be used in both ways i.e. timer and counter and comes with internal and external clock select capability.
The timer mode is used to increment the instruction cycle while counter mode increments the rising and falling edge of the pin.
When the bit T0CS (OPTION_REG<5>) is set, the counter mode will be selected and when it is cleared, the timer mode will be selected.
Brown Out Reset (BOR)
The BOR is a function that brings the controller to reset once the Vdd (voltage supply) drops below a brownout threshold voltage. There is a fine line between a BOR and Power On Reset, where the whole range of voltages is provided to protect the chip once the power drops at the voltage supply line.
In order to put the delay, mostly recommended, in returning from a BOR function, the Power Up Timer must be kept enabled.
Apart from controlling through software, the BOR mode can also be handled and configured through BOREN settings in a register.
USART
PIC16F887 comes with enhanced USART module.
This module consists of TX - A transmission pin used for
transmitting serial data to other devices and RX - A receive pin used for
receiving serial data.
Watchdog Timer
PIC16F887 comes with built-in watchdog timer that is mainly used to reset the controller when a program hangs up during compilation or gets stuck in the infinite loop of the program.
It is important to note the timer must be reset to the initial value after every 3 instructions in order to avoid it going to zero value in normal conditions.
The watchdog timer is nothing but a countdown timer and starts from 1000 and gradually goes down to zero.
Power On Reset
Power On Reset function resets the controller when it is powered on. If there comes unknown error in the chip, powering on the device will exclude it from the loop of running program and saves the device from malfunctioning.
Sleep Mode
Power saving sleep function generates a low current power down mode. This sleep mode can be terminated using an interrupt, watchdog timer or external reset.
4. PIC Compiler
- Microchip has introduced its own standard compiler for the PIC controller called MPLAB C18 Compiler. You can download this compiler online from the Microchip Official Site.
- The code written in the compiler creates a hex file that is transferred to the microcontroller to execute the certain function.
- Third party softwares are also available for compiling the program and MikroC Pro For PIC is mainly used for this purpose.
- These Top 3 PIC C Compilers give you the flexibility to pick any compiler based on your needs and requirements.
- The PICKit3 is mainly used for burning the code in the controller which is a standard PIC burner. There are other unofficial burners also available but PICKit3 is mostly preferred for the PIC controllers.
5. PIC16F887 Memory Layout and Working
The whole memory in this controller is distributed into three main types known as EEPROM, RAM and ROM Memory. All of them plays a vital role in the controller in terms of executing and calling instructions with some exceptions. Let's discuss each of them one by one.
ROM Memory
ROM memory, also known as Non-Volatile memory, which stores the running program permanently and is not dependent on the power supply i.e. has an ability to retain the program if the power supply is removed. The ROM memory is about 8K made with FLASH Technology.
EEPROM Memory
This memory is quite similar to ROM memory in one way or the other in terms of storing running program permanently with the exception i.e. the instructions in EEPROM can be modified during the operation of the controller. It contains memory space around 256 bytes, quite less than ROM memory, but enough to store the program permanently.
RAM Memory
RAM memory, also known as volatile memory, is divided into two main parts known as general-purpose registers (GPR) and special-function registers (SFR). This memory is volatile in nature as it stores the program temporarily and is power dependent i.e. once the power supply is turned off the instructions stored in the RAM will be removed.
- Registers in the RAM memory are the data holding places in the controller. A single register can hold instruction, storage address, and any kind of data including bit sequence or individual characters.
Registers are classified into two banks called Bank 1 and Bank 2 where registers from 00H to 0BH and 80H to 8BH fall under the category of SFRs and remaining are GPRs.
- Each bank contains128 bytes of memory space where first 12 locations are reserved for SFR while remaining are reserved for GPR.
Let’s discuss few registers in details.
STATUS. This register plays a role to switch between the banks. Setting fifth bit of this register shows we are discussing bank 1 while resetting it will indicate we are discussing bank 0.
TRISA. This register is used to configure PORTA as an input or output. The value 1 shows output and value 0 shows input.
TRISB. This register is identical to the TRISA in terms of deciding the pins as an input or output and used for PORTB.
W Register. All registers mentioned above are SFRs while W register is a GPR. It is not a part of any register bank and is accessible by the program only. The desired values are written on W register and transferred to the target register before writing them on the PORTA or PORTB.
6. PIC16F887 Block Diagram
The following figure shows the block diagram of PIC16F887.
- The program memory comes with 8K memory space which can configure 8192 words.
- Some pins can be interfaced with other functions of multiple devices including external interrupt, Timer0 clock input and Change on PORTB interrupt.
7. PIC16F887 Projects and Applications
- PIC16F887 is mainly used in students project i.e. controlling motors and sensor interfacing.
- Used in Central heating projects
- Production of temperature data logger
- Serial Communication
- Used in health and security systems
- Gas sensor projects
- Embedded system
- Used in industrial automation
8. Why Use PIC MicroControllers
PIC microcontrollers are widely used in most of the electronic applications because they offer easy to use interface that requires no prior skills for getting a hands-on experience with the module.
These controllers are cheap and come with an ability to perform a number of functions using minimum circuitry.
PIC controllers have outperformed
Atmel controller like 8051 in terms of their efficiency and higher processing speed.
More often than not, automation industries prefer and use these controllers for carrying out different operations as they offer very little power consumption.
That’s all for today. I hope I have given you everything related to PIC16F887. If you are unsure or have any query, you can ask me in the comment section below. I’d love to help you in any way I can. You are most welcome to give your feedback and suggestions, they help us provide you quality work as per your needs and demands. Thanks for reading the article.
Top 3 PIC C Compiler
Hello friends, hope you all are fine and having fun in your lives. Today, I am going to share Top 3 PIC C Compiler. We all know about PIC Microcontrollers because of which now we can quite easily add complex automation in our projects. So, today, I am going to share C compilers for PIC Microcontrollers. When an engineer starts working on some engineering project then he must have to choose a microcontroller. PIC is most commonly used Microcontroller in engineering projects. So, now when you have selected that you are gonna use PIC Microcontroller in your project then there comes a need which compiler to use for designing programming code for PIC Microcontroller.
It's quite a difficult as well as important decision because I have seen that once you started working on some compiler then its quite difficult to switch from that compiler to any other compiler. The reason is, you have to first learn that compiler and then you start designing your codes on it and after learning one compiler you don't want to learn any other compiler. So, today I am going to share a List of PIC C compiler which are quite useful and I consider them the best compilers for PIC Microcontroller. Before going into details, lets first have a look at what is compiler.
What is Compiler ???
- In the start when microcontrollers were newly introduced, they were programmed in Machine language which is in the form of 0 and 1. We can also call it binary language. So, programming a microcontroller in machine language was quite difficult so designers did some research and they cme up with the idea of assembler.
- In assembler we write programming codes for Microcontrollers in assembly language then function of assembler is to convert that assembly language code into machine language and create the hex file and then we upload that hex file in our Microcontroller. But, if you have worked on assembly language then you must have the idea that assembly language is also not much easy and you have to write a lot of code just to perform a simple task and then researchers did some more work and finally they invented compilers. (Thanks a lot to them :D )
- Now in those compilers, we write our code in C Language and then these compilers convert those C Language codes into machine language and we get our hex file which is then uploaded in any microcontroller like PIC, Atmel, 8051 Microcontroller etc.
- Using compilers, the programming has become quite easy, we have ready to use libraries in these compilers using which we can do complex to complex tasks in just 2 to 3 lines.
- Now in different compilers the back end generated machine code is almost same but the front end C coding syntax is quite different. For example if you are working on LCD then it has different commands for printing in different compilers. So, that's why I mentioned earlier that if you are working in one compiler then switching to another compiler is quite difficult as in that case you first have to learn the syntax of that second compiler.
- There are lots of C Compilers available in market using which we can quite easily write our programming code. For different microcontrollers there are different compilers and today, I am going to share compilers for PIC Microcontroller. So let's get started with it.
Here's the list of
PIC C Compiler,which we are gonna discuss in detail below:
- MPLAB C18 Compiler
- MikroC Pro for PIC
- CCS Compiler
Top 3 PIC C Compiler
As the topic indicates, today I am going to share top 3 PIC C Compiler. These compilers are best compilers for PIC Microcontroller. I have worked on all 3 of them and that's why I have quite an idea that all of them are best compilers. They have their pros and cons but still you can work on any of them. You can say this list is a result of my 5 years hard work. :) So, let's get started with them:
1) MPLAB C18 Compiler
- MPLAB C18 compiler comes at top in the list of top 3 PIC C Compiler as its the best one in the series. MPLAB is an official software developed by Microchip for PIC Microcontroller.
- It is free to use and you can download it from official site of Microchip.
- First of all, you need to install the MPLAB software so you should read How to install MPLAB software in Windows.
- Once you installed the MPLAB software, then you should install the MPLAB C18 Compiler so you should read How to Install MPLAB C18 Compiler in Windows.
- In MPLAB you can work on assembly language as well but using the C18 compiler you can write your code in C Language.
- MPLAB is the most flexible compiler for PIC Microcontroller as you can do anything in it with you PIC Microcontroller. But its a bit difficult to learn and program as in MPLAB you have to set every bit on your own.
- When I started my programming career, then I first started working on this compiler as I like it the most.
- So, if you want complete grip on your project then this is the compiler for you.
- If you are interested in working on this compiler then you should also read Getting started with MPLAB software.
2) MikroC Pro for PIC
- MikroC Pro for PIC comes at second place in my list of top 3 PIC C Compiler.
- Its not free but has a student version using which you can compile your up to some limit. If the size of you code exceeds that limit then you can't compile your code using it.
- Its also one of my favorite compiler because of its easiness and user friendly environment.
- MikroC has a long list of built in libraries using which you can quite easily perform your tasks.
- Its not much flexible but is very user friendly, it gives you all the setting in hand and you can set them just by clicking some combo boxes.
- These days, I am working on this compiler because its easy to use and you have a great team at its back which gives you great support. So, if you ask me then I will recommend this PIC C Compiler.
Note:
Here are few projects designed in MikroC Pro for PIC Compiler:
3) CCS Compiler
- CCS Compiler comes at third place in PIC C Compiler list.
- I have used it in some projects where there was a restriction to use this compiler.
- Its a bit difficult to learn and program because of its pure C style syntax but also has a great list of libraries with it.
- If you have already worked on C Compiler for windows then I think this one is best for you as the syntax is almost similar and you can learn it easily.
That's all for top 3 PIC C Compiler. I hope you have learn something out of it. Let me know if you have any comments and I will reply you.