Start me off with microcontrollers. Plz.

[Sorry to double-post. I just saw S.E.B and it looked a good place to post. I've cross-posted to keep replies in one place, tho I'm reading both groups. Sorry!]

Hi,

I want to get into microcontrollers, just for for and a hobby. I think my first project will be a scrolling display on an 8x8 LED, probably extended to more later. But I wanna do all sorts of stuff, just to tinker.

I'm good with programming C on computers. I understand assembly in principle if not with too much experience (messing with my old ZX Spectrum's Z80 machine code). Analogue stuff I'm a bit lost with but I can switch a transistor on and off and put in the odd current-limiting resistor. I'm good with logic.

I'd work most on a breadboard and possibly stripboard after, not into making PCBs yet.

Anyway I was thinking of starting with PIC cos it looks simple. But Arduino has much more expansibility, and with the libraries and modules, looks easy to stretch into areas without having to learn too much first, which is nice.

OTOH too much hand-holding is a turn-off to start with, I'd like to write simple machine-code routines for my scroller, etc. PIC looks nice here, and also looks cheaper, and lots of different options available for pins and features.

I think what I want is a cheap setup for PIC just to get some basic principles mastered. Could I get on with a home-made serial port thing, with just a couple of diodes etc on stripboard? Plans are on the web, doesn't look too hard, and I have an actual serial port waiting for some love. Or would that tend to run into lots of undecipherable problems and get frustrating?

For Arduino there are lots of starter kits, and cheap $5 Chinese 'ino boards. Prices vary so, so, much on almost-identical items. Sainsmart do a kit with lots of stuff but apparently abonimable documents. I'm willing to spend the 40-50 UK pounds or so to get a nice starter kit, but I want value for money, seems a shame to pay so much more than you have to. But not cheapskate, or low-quality stuff. I'd hate to spend hours blaming my own ineptitude when some Chinese capacitor somewhere is to blame.

Also I might like to be able to program Arduinos / AVRs without having to use the bootloader, in the future. Just so I could use lower-end chips and save the bootloader space. So does that need a programmer? An expensive one?

SO... as a beginner, I want some sort of practice that's reliable and easy to get early results from. Is there an easy way to start with PIC for cheap, or should I forget that and get Arduino? And what's a good kit to buy, and also a source of extra 'inos for further projects?

There's a ton of sites on the web, but no obvious indication to take one opinion over another. If someone wants to give me a setup, a price, and ideally a UK supplier (or at least Amazon or Paypal if it's foreign), I'd be very pleased and probably take the advice.

Viva Usenet!

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-------------------------------------------------------------------------------- 
"There's nothing like eating hay when you're faint," the White King remarked to Alice, as he munched away.  
"I should think throwing cold water over you would be better," Alice suggested: "--or some sal-volatile."  
"I didn't say there was nothing better," the King replied. "I said there was nothing like it." 
Which Alice did not venture to deny.

Arduino would be my recommendation, just for the amount of support and info available. Your first board should be a UNO as it is the most used and has the least number of odd quirks. I've had some from china but they came with faulty USB chips. I recommend getting the first one from Sparkfun or an official distributor. There is nothing wrong with using a arduino for a programmer - if you load the right sketch it can program other atmel chips as if it was a standard programmer plus you can make more "arduino" chips with it. Atmel programmers are really cheap on ebay.

If you want PIC you will *need* a PICKIT 3. The serial port stuff one the Internet don't support new chips (anything introduced in the last few years) and the software often won't work on operating systems later than XP. Even with XP you may have to hunt around for special drivers to give direct access to the hardware ports. Lastly the home made programmers aren't supported by the microchip IDE - you can work around that but it becomes a pain.

Also you can write the program for the Arduino in C if you want.

Yeah, your problem is too many choices. There are literally thousands of boards and processors out there, all very interesting and each with it's own unique interesting bits.

I would recommend that you visit the comp.lang.forth group and see what they recommend. You will find Forth to be a *great* language for embedded work. We are currently having a discussion on whether to design a new board for people like you (what? ANOTHER MCU board?) or to use one that exists. But several Forths have been identified that we might be able to use. I'd like to see this done on for ARM chip myself. Maybe a PSOC 5 :)

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Rick

Whatever happened to the 6502 that could run Forth? I think all it was was a 6502 with built in ROM, and the ROM had a Forth intrepreter in there.

Yes, of course it's no longer available. I don't think it was very avaiable when it was available, certainly kind of expensive. And not the right device, the 6502 having that short one page or half a page stack. But at the time, Forth was still reasonably new to most of us, and it was intriguing.

Forth certainly has the advantage that it doesn't take up much space, but can be endlessly expanded, including machine or assembly code. I've often wondered what would have happened if Forth had been the "monitor" in so many computers 30 years ago, giving the functions of those existing monitors but so much more. Of course, some people still i nsist BASIC is a good language because people need to start simple.

Michael

Actually the "forth" MCU was from Rockwell who second sourced the 6502. I don't think the stack size was any limitation for Forth. There are devices that have a much smaller stack and do quite well. You don't program in Forth the same way you do in other languages so you don't need a huge stack.

Have you heard of Open Firmware or OpenBoot on Suns? That is forth. Forth was used in a lot of things that just never got publicized.

I don't think you can start much simpler than Forth. Languages like Basic and C are much more complex in many ways... but I don't want to start a big discussion about that here. I'd just like to encourage a newbie to explore what Forth has to offer.

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Rick

To quote the revered Nicholas O. Lindan: "In spite of its numerous shortcomings a PIC is a remarkably useful tool for certain tasks. But then, so is a sharp stick."

Arduino is a great introduction to microcontrollers, where it can be important for absolute beginners to be able to have a success or two early on as an encouragement to persevere. Leaning on it too much for too long can be crippling, as one never has to deal with the messy details of setting fuses, configuring processor PLLs, GPIO setup, and so on. The reference manual for a currently popular micro, the STM32F10x family, runs to over 1000 pages.

"Naked" AVRs are available in DIP form factors as well as a ton of dev boards. Programmers (e.g.,

are inexpensive, loaders are free and the architecture is much nicer than the PIC's.

Olimex isn't in the UK but at least it's over on your side of the pond:

Their dev boards show up on many other vendor sites, plus they've got programmers.

If you want to make a million, ucontrollers are great, quite inexpensive, small, etc. But, there are a lot of restrictions on them, performance and ease of debugging are some of the big ones. Have you seen the Beagle Bone? It is an awesome system on a board the size of a credit card, and fast and capable enough to do development right on the board. It has Ethernet, USB and a wide range of built-in peripherals, plus two 32-bit microcontrollers that run at 200 MHz. It used to cost $45 which was insanely cheap, they have had to raise the price to about $55. Still a great system for tinkering and controlling just about anything.

Jon

to make a scrolling display, an arduino would be completely less overkill than a 2x 32bits uctrollers @ 200MHz !!!!! and cheaper too.

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Jean-Yves.

It's probably past the time when common 8bit CPUs could be found in electronic junk (all those clunky early cellphones, I saw some of those at garage sales, but most must have been "recycled").

But there was a time when there were articles about bootstrapping them. There was an article about the 8085 in Byte about 1980, stick NOPs on the data bus so the address bus would advance to control the RAM, and then you could stick data directly into the RAM. It was very simple, and there was a period when every scrap motherboard had about 32K of RAM in a single package (as cache), making such things easy.

There was a book put out by Dr. Dobbs about the 68000, and there the same concept was shown to bootstrap the 68000, though I never saw many of those in scrap electronics.

YOu in effect get what was so desirable about the RCA 1802, which had the ability to advance the address bus so one could put data into the RAM directly, avoiding the need for a monitor or a front panel.

The same concept of jamming NOPs onto the databus to advance the address bus was used by Don Lancaster in his "Cheap Video Cookbook".

Michael

Hi,

Thanks for all the help. In the end, I was visiting Maplin and they had the Franzis Tutorial Kit, with a Freeduino included in the box, and a few small components. Was originally 50 UKP which is a hella rip off. But it was on sale at 35, which, combined with the convenience and my impatience, I bought.

It seems like a good kit. I've had my first LEDs blinking, it's an utter breeze installing the software, writing code, and sending it down the wire. I'm glad it's been easy, cos I'm confident more complex stuff will be no less straightforward than it has to be. The kit includes a 200-page book, and a CD. I think originally German, but in good English, gods help me it's better than Chinese!

I think I've been put off the PIC from what people have said. Sounds like more of an ordeal, each man climbing his own mountain kind of thing. Arduino software feels really hand-holdy. I think for projects in the future, I'll either buy more of the cheap tiny $5 Chinese inos, to run stuff after I've prototyped it on my kit, or maybe find out how to program raw ATMEGA chips and use those.

Thanks a lot for the help.

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-------------------------------------------------------------------------------- 
"There's nothing like eating hay when you're faint," the White King remarked to Alice, as he munched away.  
"I should think throwing cold water over you would be better," Alice suggested: "--or some sal-volatile."  
"I didn't say there was nothing better," the King replied. "I said there was nothing like it." 
Which Alice did not venture to deny.

One can use ladder logic for the program; see:

And use PicKit2 which should be available at rater low cost.

--- "still insist"???

You seem to be implying, in an underhanded way, that BASIC is a good language for neophytes, but not once they've "grown up".

Why would you do such a thing?