Any recommendations for a good overview of pic and basic stamps

While in the process of trying to find a solution to a problem, I
received several suggestions that PIC or Basic-Stamps might be a
solution. In order to fairly evaluate those suggestions, and decide
whether or not I'm capable enough to use that approach, I'd like to get
a good overview of what I'll be facing. I've joined another e-list for
basic-micros -- Parallax's forum -- but so far I haven't received an
adequate answer to the questions that I'll pose here. I _think_ this
would be on-topic here, and I hope no one minds.

What I'm looking for is links to sites that will give a broad general
explanation to a complete novice of the nature and potential of PIC and
Basic-Stamps; I've done a some googling without coming up with anything
that is very helpful, so I might be way off base right now.

My impression is that these are simply chips that can be programmed
(perhaps something like an EPROM?), but it is done with very simple
basic-language programs that are fairly short with relatively few
instructions, and that the programming is done on a computer and then
loaded onto the chip via a cable linking the chip and a PC. Then the
chip can be installed on a small circuit board of some sort (e.g., a
thermostat), after which it is then able to run the basic-program
completely independent of the PC. Besides my thermostat needs, I can
see possible future applications in my beer brewing hobby, so I am
definitely interested at this point; for example, if I'd eventually like
to build either a RIMS or HERMS (for non-brewers, that would be a
"Recirculating Infusion Mash System" using a magnetic pump to circulate
the liquid in the mash to help keep it uniform in pH and temp, and a
"Heat Exchange Recirculating Mash System" which also actually controls
the temp through various stages). Both of those systems can be designed
to be fully computerized with temp sensors, PID controllers, solenoid
valves, and magnetic pumps.

At this point I'm not seeking technical help to solve a specific
problem. Rather, I'd just appreciate some insight into what I'd likely
be facing in this area, and also the sort of other 'fringe' benefits
(like a cool hobby) that I might derive from this in order to become
involved; for instance, if I purchase a bit of equipment, take my time
learning all of this stuff, and then build my project, what other sorts
of things can typically be done with this technology? What sort of
costs am I facing -- at a minimum -- especially if I have only a
soldering iron and a simple multimeter? What kind of learning curve
will I be facing? ... and will I need to learn the equivalent of what it
takes to earn an associate's degree, or perhaps just a single college
course? Is there a website or FAQ page that will start me out with a
good overview of this area of technology, explaining how the entire
process works?

Thank you for any help.

Bill Velek

 

I don't know of any websites that directly address this, but I'll make an effort to explain it
here. If you have questions not answered here, feel free tocontact me directly at
[email protected](removethis)rentron.com

First, the learning curve is by far the least with the BASIC Stamp. The number of application
notes and code examples provided by Parallax, and the ease of use for the Stamp definitely
lower the learning curve.

Stamp application notes with code examples, BASIC Stamp editor/compiler/download software
here. http://www.parallax.com/html_pages/downloads/index.asp

In the downloads section look for the Nuts & Volts articles. You'll find enough complete projects
and sample code there to keep you busy for a good while.

If you look under the Educational Curriculum downloads section you can download .pdf documents
for Applied Sensors, Understanding Signals, Elements of Digital Logic, What's a Microcontroller,
Basic Analog and Digital, Industrial Control, and a few more.

Even if you never purchase a BASIC Stamp, these are still excellent tutorials for basic electronics,
and embedded controller applications in general.

The BASIC Stamp is a pre-programmed PIC microcontroller soldered onto a small module that
contains the PIC, an external EEPROM (where your code is stored) and a few other components
like the +5V regulator, RS232 (PC interface), and a few other support components.

The pre-programmed PIC on the Stamp has the BASIC interpreter. Your program code is compiled
with the PBASIC compiler which is built into the free Stamp editor/compiler you can download for
free from http://www.parallax.com

Once compiled your program is sent to the EEPROM on the Stamp module as tokens. A fancy
word for how the code is compiled & stored. On power-up, the PIC on the Stamp enterprets & runs
your code by fetching it from the external EEPROM.

Parallax offers several versions of the BASIC Stamp. You can find a list with details, types, and
instruction limits with user code execution times at the link below
http://www.parallax.com/html_pages/tech/faqs/stamp_specs.asp

On the other hand, you can program the PIC directly. There are free tools, and some you pay for.
Microchip provides a free assembler available at http://www.microchip.com and there are PIC BASIC
& C compilers as well. We carry them here http://www.rentron.com/PicBasic/PBP.htm for BASIC
compilers, programmers, etc, and C compilers here http://www.rentron.com/CCS_C/CCS_Compiler.htm
We also carry an excellent PIC C course/compiler here http://www.rentron.com/C2C.htm

You can find plenty more with a quick search from any major search engine by simply entering PIC.

You can browse through our online BASIC compiler PIC projects section here
http://www.rentron.com/PicBasic1.htm and assembly projects section here
http://www.rentron.com/pic.htm for an idea of what you're in for using the PIC
by itself.

The learning curve & costs are higher, but you have the lower price per project once you have the
tools like compiler & PIC programmer. Your code is burned (programmed) directly into the PIC,
but not in external EEPROM like with the Stamp, and consequently it runs much faster on the PIC
than on the Stamp. There are EEPROM versions and flash versions. The EEPROM PIC part will
be a number like PIC12C671. Flash-based will be like PIC12F675. C denotes the EEPROM version.
The F denotes the flash based version. C parts are normally OTP (one time programmable). F parts
are flash based, and you can program them up to ~100K times before discarding them.

The PIC code execution times are whatever the oscillator speed is /4. I.E. a PIC running at 4MHz
will execute single-cycle instructions at 1/4MHz = 1 million instructions per second. At 20MHz
it's 5 million instructions per second, and newer 18F parts that can operate up to 40MHz for 10
million instructions per second. Pretty quick when you think about it.

It's a very cool & fun hobby once you get started.

Explore the Nuts & Volts articles & other links above for a good idea of what you can do
with the Stamp, PIC, and pretty much any other embedded controllers.

Normally you'll need at least a breadboard, power supply, wire, and discreet components
like capacitors, resistors, ect, but this is normally going to be dictated by whatever you
decide to build. Then of course add-in the cost of your prefered controller, and other related
equipment.

With the Stamp, Parallax application notes, and other documents from the Parallax downloads
section you really only need an understanding of basic electronics, and you're ready to get
started. We also carry BASIC Stamp starter kits & HomeWork boards.
http://www.rentron.com/PicBasic/stamp_stuff.htm

With the PIC you're looking at a higher learning curve, and initial expense of getting everything
you need to get started. There are pros & cons to both solutions, but the Stamp is what I would
recommend you start with if you're new to this.

I taught basic electronics, computers, and embedded programming for the State of Colorado
for about 12 years. I started everyone out on the Stamp first, then moved onto the 8051 and
PIC controllers starting with assembly, then BASIC, then C.

You will at some point want to learn assembly language so you'll know what's going on under
the hood if you start out with a PIC compiler.

I highly recommend starting out with the BASIC Stamp first, then moving on to whatever you
feel best suites your application requirements, needs, and abilities.

Like everything else, it' only hard until you know it. Just depends on how much time you have,
and your motivation factors.


-Bruce
http://www.rentron.com

 

You might look at the PICAXE at http://www.picaxe.co.uk. A very small
fraction of the price of the Basic Stamps with far more capabilities.

For example, the PICAXE-08M is about $3.25 and is comaprable with the
$29.00 Basic Stamp 1 with the added capability of 10-bit A/D and PWM.

The PICAXE-18X at $10.00 is comparable with the $49.00 Basic Stamp 2.

The software and docs are free at the PICAXE website. You wil need a
breadboard of some type, a source of +5 VDC and a connection to the PC
COM port.

There are many applications at the PICAXE site. More at my site;

http://www.phanderson.com/picaxe/picaxe.html

Most code written for the Basic Stamp can be adapted to the PICAXE
with minimal effort.

Another plus for the PICAXE is that they are modern PICs and you can
move your design to good quality boards such as at;

http://www.olimex.com/dev/ See "PIC"

Best wishes.



PH Anderson

 

Bravo Peter-I couldn't have put the Picaxe case better myself ! In
addition Picaxes occupy only a classic DIP8/18 etc IC footprint, so
ones overall ones circuitry will be more compact than a BS equiv. In
2003 we had late teen entry level electronics students here in NZ
design/build cheaply Picaxe-08 dataloggers(c/w battery) inside an
empty 35mm film canister. See => www.picaxe.orcon.net.nz/spider08.jpg
& => www.picaxe.orcon.net.nz/film08.jpg

 

Been pretty busy the past week, and am just now catching up. Thank you
to the following for their responses and help:
'Bruce', Peter Anderson, and 'Manuka'.

Bruce, I want to digest stuff a bit before I start asking questions.
I'll post later.

Thanks.

Bill Velek -- remove the "--NO-SPAM--" from my email address