cubdh23 said:
Ok now i am dead serious about buying a PIC and a programmer. I need to jump on the PIC bandwagon now because i have only experience with the costly 112pin motorola processor which is ridiculous for small projects..
Ok i have a few questions. First of all.
1) what site can i buy the cheapest, programmer board?
You don't have your location filled in, so we don't know what country you are in, so it's rather difficult to make recommendations for a specific site!.
However, you should be able to buy a kit for the P16PRO40 pretty well anywhere, and various sites will post anywhere in the world.
2) what do each of these things mean e.g 16F648A
I assume 16 means 16 i/o what does the 64 mean and what about the 8A.
'16' means it's a '16 series' PIC, which is a mid-range PIC and actually uses a 14 bit core, the 'F' means it's FLASH or EEPROM (mostly EEPROM) which means it's capable of being easily reused. The 648 is the specific designation for that chip, and the A means it's a later silicon version than one without the A.
3) How do i know if what i am gettting is "One time programmable"or 1,000,000 time programamble?
See above! - look for an 'F' in the type number, a 'C' is usually OTP, and if it has a JW at the end it's also UV eraseable. You could also look on MicroChip's website, where you can list them by various criteria.
4) lets say i need 30 pins for my project and i have 2 16 pins pics
can i hook up the 2 pics to in effect have 32 pins?
You can, but it's up to you how you implement it, you need to design some kind of communication protocol between them, a lot depends on what you are doing and why!. Probably easier to go for a bigger PIC, the 16F877 is a popular one and has 40 pins - the datasheet will tell you how many are available as I/O.
5) There are tons of different PICs, which should i get? i guess it makes sence to buy a bunch of them.
Try following my tutorials, I would suggest starting with the 16F628, then the 16F876/7 and 16F819. Once you've got used to those, you could try moving to the high-end PIC's, the 18F series.
There are basically three ranges of PIC's, the 12 bit (12 series), 14 bit (16 series), and 16 bit (18 series) - I would advice you start on the 16 series (14 bit) as I suggested above - most code is written for this series, as are my tutorials.
6) My previous processor had input capture/ output compare capability.
Do PICs have this capability? I checked micropics site and didnt see mention of this. I want a PIC with this capability.
I don't quite understand what you mean, the 16F628 has analogue comparator inputs? - what are you wanting to do?.
7) Do Pics have preassigned functions like Reset, interrupts in memory?
The reset vector is 0x0000 on most modern PIC's (it wasn't always), and the interrupt vector is 0x0004.
8) Why do i always hear about people using crystal clocks. isnt the crystal built inside the Pics?
No, some have an inbuilt RC oscillator (like the 16F628 and 16F819), most require an external oscillator.
9) Are the instructions the same for all Pics?
They are upwards compatible, the 16 series have more instructions than the 12 series, and the 18 series have more instructions than a 16 series. Generally you can run 12 or 16 series code on an 18 series, but not the other way (unless the code only uses the smaller instruction set).
10) In Nigel's site. Is that software the assembler? where do i find the software that assembles the code and gets it ready for burning?
No, the assembler comes from MicroChip, it's called MPASM and comes as part of MPLAB - it's a free download, but fairly large.
11) Most importantly where can i find a good, cheap programmer. Is it cheaper/ too hard to build my own?
As above, look for P16PRO40, one common low cost kit is the DIY Kit96, from DIY Electronics in Hing Kong, but available worldwide.
If you're in the UK, try Quasar Electronics.