Need some experienced advice

[skimask]

Yea its expensive, But if you look you end up with about 900 bucks worth of stuff dev boards, the pro compiler etc...so I figured it was really only about 1000 bucks. I have NOT taken the class but was considering it. Hence my question....

And I agree that I have learned more blowing things up then I ever learned in school.

Thanks for the reply
Bill12780

Glad to see you didn't waste your time.
I can tell you that there's probably at least a dozen people or so around here that could probably do an equal if not better job at the same type of thing you were talking about...just change the initials and you're in there...in my case it would be something like jdgresearch. I should do that and charge half the cost.
(Incidentally, I don't see $1,000 worth of stuff there...)

[bill12780]

Glad to see you didn't waste your time.
I can tell you that there's probably at least a dozen people or so around here that could probably do an equal if not better job at the same type of thing you were talking about...just change the initials and you're in there...in my case it would be something like jdgresearch. I should do that and charge half the cost.
(Incidentally, I don't see $1,000 worth of stuff there...)

If you have the expertise to do it...I would talk about a cherry gig! I got the 900 figure from them. They said it includes a dev board, compiler, editor a hand full of PIC's adapters, programers, sensors, motors, LED's all kinds of stuff basically a "everything you need to start" kinda thing.

I did not really need it cause I can order a dev board from MEL and then upgrade my old version of PBP for 25 bucks. I already have a epic programer. But was looking at the USB one they have now.

I also have the book by chuck helbuck(sp?). So I think I just need to lock myself in the basment and go to town!

I know its not "approriate" but what do you guys think of the atmel stuff? I have heard its cheaper (cost per unit) and they are more "universal" in architecture (8051 or arm cant remember)

Again, thanks for the input and the information...I love a good forum.

Once I get up and running I will try and give my advise on the electronics side of stuff that is my forte.

Bill12780

[skimask]

Take a look at the compiler/dev board packages available at www.melabs.com and/or www.mikroe.com/en (not neccessarily mikro's compiler but the dev boards).

Everything you need - you could probably get a 'grab bag' from Jameco for about $25

Programmer - can't beat the USB PICKit2 direct from Microchip for $50-ish

ATMEL vs. PIC - to each their own. I've messed with both. It seems to me that the architecture of the PIC is superior, but that's just me, and I started out with Z-80/8085/Intel types and then switched over.

[bill12780]

Thank you all for the input on the class. Maybe its a good thing I did not go. (the world may never know!)

But what about a good solid chip to start with. Do they make one with a built in RS-232? eventually my project will need to interface to a RF module that is controlled via RS-232.

Like I said before the keypad project will be basically enter a code, allow the user to run a motor one direction or the other. (This is obviously over simplified because there will need to be several levels of codes for different reasons...)

Save me HOURS of combing though datasheets and give me your opinions here!

Thanks everyone!
bill12780

[SteveB]

Hi bill,
I'll poke my nose in here and suggest the following:

You can start with either the 16 or 18 series, but I would go with the 18 series. Disadvantages to doing that are the 18 series does not have any real small pin count options (like 8pin), and older books won't cover them as well.

Some chips I like:
18F4620 (40pin) or 18F2620 (28pin) - Has most of the available hardware functions (I2C, SPI, A2D, USART, Etc), loads of memory, and runs at 32MHz on the internal clock.

18F4550 (40pin) or 18F2550 (28pin) - Similar to the above, but with USB support if you want to dive into that.

Others will have their own preferences. A parametric search on Microchip's site will turn up a lot of options. Selecting the functions (like USART) you can't live without, memory size, pin count, and such will narrow the field nicely.

You'll find lot's of help here, especially if you put the work in on your side.
All the best as you start learning. Welcome!
SteveB

[Melanie]

> What is a good solid chip that is cheap (comparable to the atmel chips) that will work for me.

This depends on the number of I/O's you need...

For up to 16 I/O's the cheap 16F628A is a good choice. (a) You don't need an xtal (unless you're doing async comms) because it works from it's own internal oscillator, and (b) it handles MCLR internally for you too. So all you need is a program, some volts and it works!

I'll go with skimask's recommendation... forget any and all training courses. Equip yourself with a good programmer, latest version of PBP, a handfull of PICs, the Datasheets are free, a breadboard, good PSU, LCD with flying leads on it, and you're in business.

If you don't know how to do something, then cobble together a little test program to display the result on the LCD. You'll learn more that way than any course.

[skimask]

I'll go with skimask's recommendation...

WHOA! Did I read that right! Did Mel go with MY recommendation? (head swelling, I'll let you know when the pressure gets to be too much )
Learned all I can, I have...but a Jedi, I am not...

I'd say go with a PIC18F4550 and associated hardware, programmers, etc.
You can get it in a DIP package (which means you can mess with it on a solderless protoboard), it's got plenty of I/O and memory, plenty of functionality, and it's got USB ports...which, no, they aren't really for a beginner, but they are there for future toys.

[bill12780]

I cant tell you how nice it is to get some good help as a noob on a forum. It is RARE! I read a sticky from Melanie about this and it must have worked!

I do appreciate all the suggestion on chips. I will get the datasheets tonight and look them over.

If you all can handle it. I do have more questions....

1) How big a problem is it moving from one chip to another. Example. Lets say I choose one chip and find I don't have enough space for the program. Are there "other" versions of the same chip with more memory? I mean pin for pin compatible? Otherwise, how do you even begin to estimate how big your program is going to be?

2) I mentioned my project is keypad based. Have any of you heard of or know what the advantages are to using a 74c922 keyboard decoder? I have seen other designs that dont use them and some that do? Like I mentioned before I am an electronics guy (mostly analog stuff) so I have never used a 74c922. I do understand that the decoder will reduce Inputs needed on the PIC and the debounce is controlable. I guess what I am asking is more from a "Coding" point of view/use with a PIC perspective.

3) What do you all think of the MEL lab-x1 dev board? I feel when making purchases its always best to ask the man(or woman) that owns one. Also, is my epic programer still gonna be ok with the new chips. Or should I invest in a USB programmer.

4) What about the PIC-AXE with the bootloader? If I am not mistaken would this not me similar to like having a Jtag port? As Ricky Ricardo would say "splain it to me"

Man, I cant tell you how refreshing it is to go to a forum and not get slammed for being ignorant...(Ignorant has in un-informed---not stupid that is different!)

Thanks again, and if anyone needs electronics help I will do my best!

Off to the MICRO-CHIPS website for some datasheets!

bill12780