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Microcontroller newbie

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Nick'

New Member
By the way, since i am new, I would like to know which model of PIC i should buy. Because there are dozens out there to choose. I probably not going to buy all. Maybe just 1 or 2 (of different models).
 

birdman0_o

Active Member
Go to microchips sample site to order your first ones. I would suggest the 16f628a to start off , if you really want two different kinds maybe get a 16f88 or 16f690 as well.
 
By the way, what are their differences? They are all 8 bits right? Differences?

The main difference between PICs is their features (whether they have on-board USB, MSSP/USART/UART, ADC, internal oscillator, etc) and their number of I/O pins. I use the PIC16F876A (28-pins). It's a pretty nice device in a small package and has a lot of the more useful features, though it does require an external oscillator.

Oh, and I forgot to mention another important difference between the various PICs: RAM and Flash capacity. If you need to use really complex programs, you'll want a spacious chip. The 16F876A has 8Kwords of flash and 368 bytes of RAM.
 
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Pommie

Well-Known Member
Most Helpful Member
If you are staying with 16 series chips then I would suggest the following,
18 pin - 16F88
28 pin - 16F886 (876A with internal oscillator)
40 pin - 16F887

Although, there is very little example code for these (on the internet) as they are the newest chips, the modifications required to get anything working are very minimal and plenty of posters here will help. However, if you intend locking yourself away and going through tutorials, you may be better off with the 16F628A, 16F876A and 16F877A.

Mike.
 

gaspode42

Member
Nick

Yes, the more pins you have then the more ports you have available for output/input.
The oscillator determines how fast the micro-controller will perform your code, one code instruction is executed for every 4 clock cycles so if you have am 4MHz clock your 'application' will run at 1Mhz or 1 million instructions per second.
 
Probably i will buy this. 18 pin is enough right? By the way, what is the difference between 18, 28 and 40 pins? Is it the I/O?

Secondly, What is oscillator used for?

Yeah, for example, the 16F628A (18 pin device) has PORTA and PORTB, PORTB containing 8 bidirectional I/O pins, and PORTA containing 7 bidirectional and 1 input-only I/O pin. The 28-pin 16F876A has 6 I/O pins on PORTA, 8 on PORTB, 8 on PORTC, and the 16F877A has these, plus another 8 I/O pins on PORTD and 3 on PORTE
 
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Nick'

New Member
Nick

Yes, the more pins you have then the more ports you have available for output/input.
The oscillator determines how fast the micro-controller will perform your code, one code instruction is executed for every 4 clock cycles so if you have am 4MHz clock your 'application' will run at 1Mhz or 1 million instructions per second.
Ic, But the chip i am going to buy does not have built-in oscillator. What should i do then? External? How?
 

rajbex

Member
Yes, the 28 and 40 pin microcontrollers have more input/output ports. Some come with in-built Analog to Digital Converters.
The Oscillator is used for timing and control of event sequences in every digital circuits.

Raj (Experiments with PIC16F628A)

Probably i will buy this. 18 pin is enough right? By the way, what is the difference between 18, 28 and 40 pins? Is it the I/O?

Secondly, What is oscillator used for?
 

gaspode42

Member
Nick

Have a look here
 

AtomSoft

Well-Known Member
heh that doesnt help much... what is the RC time constant?

What values are used to produce what (m)hz?
heh i get it now but i think the below better explains it
 
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