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We got some good comments on Basic Stamp. As far as hobbyist usage - I used it to build controller for DDS ( direct digital synthesis) oscillator for ham radio and found it too slow to handle optical encoder, LCD display and the DDS oscillator all at once. But I have to admit I learned how to build an efficient code to fit into Stamp memory.
\
Than I switched to Parallax SX chip which has 8*2k pages of memory. In my next project I used this SX chip to extract timing code from WWVB 60kHz radio signal. Again two major hardware channels – radio receiver and the LCD display. Found the 2k ?page" code limit and its necessary switching cumbersome and error prone.
As far as my negative outlook on the company support – just check how may newcomers have a problem getting the chip to communicate with the PC when they turn it on first time.
I had a few e-mails exchanges whit Parallax to get them to describe the error codes and I not get anywhere. I was left with an impression they really do not know how Stamp starts to communicate with PC. There was lot of - try this, try that - including "use fresh battery"!
And their answer on adding USB support to Stamp – if you do not buy our USB adapter with our driver you are on your own.
Common, Widows are build on driver philosophy and the USB to serial chip in use is build basically by one company. So what is so special with Parallax USB ?

My current project I plan to modify my WWVB code to drive Nixie tubes and than to replace the SX with processor with USB port and C programming language.

And my "dream project"? Replace annoying menu driven control of my ham radio with real time voice (recognition) interface.

Vaclav AA7EJ

At 05:12 PM 1/30/2011, Andy Mathison wrote:

>everyone seems to have forgotten PICAXE.......Really easy to use, very cheap
>(UK Government subsidy), no programmer needed, all software is free to
>download, great Forum, really fast chips with a lot of I/O or
smaller ones with
>less.....lots of support, pcbs, and third party units, all over the
world.....

All this discussion on the micro controllers sound really neat. I've
wanted to try
and play with one, and been looking at a couple. Radio Shack had a Basic stamp
kit and ARRL had a PIC (don't remember what now) with a fairly large book to
go along with it.

I was wondering what you all are using them for. I can see if you're a design
engineer for an appliance company and need something for your stove, refig,
or microwave. But what are the hobbiest doing with them?

Just curious, and looking for something to do with one, if I spent the money to
play with one.

John

John T. Blair WA4OHZ email: jblair1948@...
Va. Beach, Va
Phone: (757) 495-8229

48 TR1800 48 #4 Midget 65 Morgan 4/4 Series V (B1106)
75 Bricklin SV1 (#0887) 77 Spitfire 71 Saab Sonett III
65 Rambler Classic

Morgan: www.team.net/www/morgan
Bricklin: www.bricklin.org

If you can read this - Thank a teacher!
If you are reading it in English - Thank a Vet!!

Here is the schematic to the version of the circuit that was in a Radio Shack "engineer's notebook". Always wanted to build it, never found the time...



C.W.

--- In Electronics_101@..., "Chris" <ctwardell@> wrote:

Sometime back in the late 70's or early 80's there was an article on a 10x10 LED "scope" in Popular Electrics magazine, either Forrest Mims or Don Lancaster I think wrote it. It was based on the LM3914 and a few other cmos chips for scanning, gating, etc.

C.W.

--- In Electronics_101@..., "logicresearch" <logicresearch@> wrote:

I had plans somewhere for a unit using LM3915's (or was it LM3914's) anyway it was basically suited for audio frequencies only.
You could always replace those chips with a series of LM319's or some sort of fast op-amp and cascade as far as you like for a matrix as big as you like, as long as you get enough LED drive.

Daryl
LogicResearch/ProjectElectronic

--- In Electronics_101@..., Bernab?? <benny7440@> wrote:

I would like to know if someone has done it or, at least, tested (mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250 KHz it has potential practical uses!

-----Original Message-----
From: Electronics_101@...
[mailto:Electronics_101@...] On Behalf Of Bud Corazza
Sent: Sunday, January 30, 2011 7:37 PM
To: Electronics_101@...
Subject: Re: [Electronics_101] Re: Selecting microcontroller
for hobby projects - opinions wanted.


----- Original Message -----
From: "jong kung" <jongkung01@...>
To: <Electronics_101@...>
Sent: Sunday, January 30, 2011 6:38 PM
Subject: Re: [Electronics_101] Re: Selecting microcontroller
for hobby projects - opinions wanted.

Jong:

I agree.

I used the PICAXE 08 (their smallest) to build an ampere-hour
meter described in a recent QST Magazine. I liked it. It uses
a limited BASIC which is more than sufficient. My next
project will use another PICAXE, but one with more ADCs and DI-DOs.

The "downloads" from the development system are via a USB to
serial converter cable ($25 from SparkFun). I think there is
a chip in the cable.
It was the most expensive item I had to purchase. Everything
else was either cheap or free.

Bud

everyone seems to have forgotten PICAXE.......

I haven't. I mentioned it. I really am chopped liver around here.

;-)

=====

Really easy to use, very cheap (UK Government subsidy),

But still BASIC. I have no problem with it. But it seems
others might think so.

====

no programmer needed,

It needs a serial (RS232) connection. Most new computers (especially
laptops) don't have SERIAL ports. There seems to be some
limitations on what kind of USB-Serial converter may and may not work:



====

By the way, how is it that the PicAxe can communicate using
RS232 standard (negative voltage levels) without a converter?


Jong

Sometime back in the late 70's or early 80's there was an article on a 10x10 LED "scope" in Popular Electrics magazine, either Forrest Mims or Don Lancaster I think wrote it. It was based on the LM3914 and a few other cmos chips for scanning, gating, etc.

C.W.

--- In Electronics_101@..., "logicresearch" <logicresearch@> wrote:

I had plans somewhere for a unit using LM3915's (or was it LM3914's) anyway it was basically suited for audio frequencies only.
You could always replace those chips with a series of LM319's or some sort of fast op-amp and cascade as far as you like for a matrix as big as you like, as long as you get enough LED drive.

Daryl
LogicResearch/ProjectElectronic

--- In Electronics_101@..., Bernab?? <benny7440@> wrote:

I would like to know if someone has done it or, at least, tested (mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250 KHz it has potential practical uses!

I had plans somewhere for a unit using LM3915's (or was it LM3914's) anyway it was basically suited for audio frequencies only.
You could always replace those chips with a series of LM319's or some sort of fast op-amp and cascade as far as you like for a matrix as big as you like, as long as you get enough LED drive.

Daryl
LogicResearch/ProjectElectronic

--- In Electronics_101@..., Bernab?? <benny7440@> wrote:

I would like to know if someone has done it or, at least, tested (mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250 KHz it has potential practical uses!

everyone seems to have forgotten PICAXE.......

Really easy to use, very cheap (UK Government subsidy),

no programmer needed,

--- In Electronics_101@... <mailto:Electronics_101%40yahoogroups.com>, Bernab?? <benny7440@...> wrote:

I would like to know if someone has done it or, at least, tested

(mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site

when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250

KHz it has potential practical uses!

The LED matrix isn't part of the problem. You could spread a 1 nS rise time over 20 columns of LEDs if you could process the signal.

The problems: grab a signal, attenutate it, couple it (AC, DC), sample it at some high rate (analog to digital conversion), store the samples, display the samples. This simplistic sequence overlooks: external sync, delayed sweep, dual channel, offset X and Y position and, I'm sure, a few other important things.

LEDs are not the problem.

Here's an LCD oscilloscope that will display signals up to 1 MHz (perhaps more) and costs about $60.



It is single channel with no external sync or any other features and costs about 25% of a used Tektroni 485 300 MHz scope which does have all the features.

A more capable USB scope;



for about $250 amd it has a lot of features. I still wouldn't trade if for my 485 plus a logic analyzer I built from



There are a lot of 'PC Sound Card' scope projects around and there are a lot of USB scopes; just try Google.

For many years I used a 10 MHz Heathkit oscilloscope that I built from a kit. It worked very well when I was working at low speeds. I think the fastest thing I ever had to do was watch the data recovery from an 8" floppy controller I built way back when. I don't recall the speeds but it seemed fast at the time!

Today, everything works at 50 MHz and up. You don't always need to see those frequencies and many signals such as SPI and I2C are down in the 400 kHz to 10 MHz range. Still, a 300 MHz scope guarantees that you can see what is going on. Sometimes you don't really care WHAT is going on as long as something is happening. On other occasions you just really need a logic analyzer.

None of my hobbies are cheap and electronics is no exception.

Richard

I would like to know if someone has done it or, at least, tested (mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250 KHz it has potential practical uses!

-----Original Message-----
From: Electronics_101@...
[mailto:Electronics_101@...] On Behalf Of vaclav_sal
Sent: Sunday, January 30, 2011 5:49 PM
To: Electronics_101@...
Subject: [Electronics_101] Re: Selecting microcontroller for
hobby projects - opinions wanted.

We got some good comments on Basic Stamp. As far as hobbyist
usage - I used it to build controller for DDS ( direct
digital synthesis) oscillator for ham radio and found it too
slow to handle optical encoder, LCD display and the DDS
oscillator all at once. But I have to admit I learned how to
build an efficient code to fit into Stamp memory.
&#92;
Than I switched to Parallax SX chip which has 8*2k pages of
memory. In my next project I used this SX chip to extract
timing code from WWVB 60kHz radio signal. Again two major
hardware channels - radio receiver and the LCD display. Found
the 2k "page" code limit and its necessary switching
cumbersome and error prone.
As far as my negative outlook on the company support - just
check how may newcomers have a problem getting the chip to
communicate with the PC when they turn it on first time.
I had a few e-mails exchanges whit Parallax to get them to
describe the error codes and I not get anywhere. I was left
with an impression they really do not know how Stamp starts
to communicate with PC. There was lot of - try this, try that
- including "use fresh battery"!
And their answer on adding USB support to Stamp - if you do
not buy our USB adapter with our driver you are on your own.
Common, Widows are build on driver philosophy and the USB to
serial chip in use is build basically by one company. So
what is so special with Parallax USB ?

My current project I plan to modify my WWVB code to drive
Nixie tubes and than to replace the SX with processor with
USB port and C programming language.

And my "dream project"? Replace annoying menu driven control
of my ham radio with real time voice (recognition) interface.

Vaclav AA7EJ

I would like to know if someone has done it or, at least, tested (mathematically,) the idea of, with an appropriate size led-matrix, construct a 'kind' of oscilloscope & for what range of frequencies it's useful?

The idea occurred to me the other day while browsing this very site when I stumbled into a post of a matrix of leds. Sorry, don't remember what was the purpose of the circuit nor the amount of leds involved.

Thanks in advanced for any comments on the subject!

Note: If it can be done with a frequency response of at least 250 KHz it has potential practical uses!

I'm going to second the Arduino (AVR) suggestion.

If there is a local hackerspace in the area, pay them a visit and see what they are using. Your local hackerspace will probably be able to get you up and runninng on the Arduino platform quickly and show you some examples. There's a reason the platform is so popular.

Meredith G.
www.6smith.com