BS2 usage without BOE or Homework Board

servello

Greetings,

Please forgive me if this question seems to be rather simple with an equally simple and obvious answer.

After working through the first 4 chapters of "What's A Microcontroller?" and doing some study of electronics on the side, I thought I'd like to experiment by 'breaking-away' from the 'hand-holding' nature of using the BOE and popping the BS2 into a standalone solderless breadboard.

** See·attached photo,·schematic and PBASIC code·**

It seemed pretty straight forward.

On a 5V powered solderless breadboard:
Place a lead from Pin21·(VDD) to the positive (+)·rail
Place a lead from Pin23·(VSS) to the negative (-) rail
Place a resistor (470 ohm)·from Pin13·(I/O) to the positive (+) rail
Place a lead from Pin13 to an unused slot on the board
Place·LED anode leg to that same row
Place LED cathode leg to the negative (-) rail

As can be seen in the photo, it worked out very well.

I, of course had to upload my program to the BS2 to tell it what to do (blink an LED in this case). I did this by my usual method of having the Stamp·placed onto my Board of Education, typing the code into the PBASIC 2.5 Editor and finally uploading the code·to the Stamp (via USB cable).

Then, I had to remove the Stamp and place it into the solderless breadboard to complete my circuit. Needless to say, this would be quite tedious to do each and every time I wanted to try a new circuit.

To save me from doing the above time and time again, I would need a way to have the BS2 remain on the solderless breadboard and have the ability to upload my programs to it.

OK. Now the question (yes, there actually is one ).

What I'd like to know is, if·the tool I'm looking for is·the Parallax·USB2SER FTDI FT232BM USB to Serial Development Tool?

http://www.parallax.com/Store/Accessories/Tools/tabid/162/CategoryID/37/List/0/Level/a/ProductID/32/Default.aspx?SortField=ProductName%2cProductName

Any help will be much appreciated.

I made this post as specific as I could·with included attachments and a link·just in case another newcomer might have this same question.

Best,
Dominic

allanlane5

Well really, I think you want one of these: http://www.parallax.com/Store/Accessories/CablesConverters/tabid/166/CategoryID/40/List/0/Level/a/ProductID/379/Default.aspx?SortField=ProductName%2cProductName

And if they're not in stock, then one of these: http://www.parallax.com/Store/Accessories/CablesConverters/tabid/166/CategoryID/40/List/0/Level/a/ProductID/378/Default.aspx?SortField=ProductName%2cProductName

along with one of these: http://www.parallax.com/Store/Accessories/CablesConverters/tabid/166/CategoryID/40/List/0/Level/a/ProductID/33/Default.aspx?SortField=ProductName%2cProductName

And you'll need to make an adapter to go from the DB-9 to your white-board -- basically a DB-9 F with 4 wires added to it -- 2, 3, 5, and I think 8, and wire 6 and 7 together.

The BS2 programming port wants 'true' RS-232 signal levels -- +- 5 volts to +- 10 volts.· The USB to Serial adapter above does this.· The "FTDI" unit you called out does not.

MSDTech

If you want to use a basic stamp on a breadboard and don't mind doing a little soldering, try the OEM kits:

http://www.parallax.com/Store/Microcontrollers/BASICStampOEM/tabid/135/CategoryID/10/List/0/SortField/0/Level/a/ProductID/21/Default.aspx

or

http://www.parallax.com/Store/Microcontrollers/BASICStampOEM/tabid/135/CategoryID/10/List/0/SortField/0/catpageindex/2/Level/a/ProductID/501/Default.aspx

These both fit very nicely on a standard breadboard and still have the RS-232 attachment (see attached photo of a Basic Stamp 2 OEM in use).

westaust55

Off topic in terms of USB conenction but . . .

looking at your schematic, you show the LED from +5Vdc (Vcc) to the junction of a resistor to a STAMP output AND GROUND.
While the resistor will protected the STAMP, by the schematic, the LED is across the full 5Vdc.

Remove the link from the junction of the LED and resistor to ground.

I presume that the circuit on the bread board omitted this connection.

servello

Thanks for the quick replies.

I went over all the recommendations and links. All usefull ideas.

For simplicities sake and ease-of-use, I think I'll purchase the Parallax BS2·OEM Module (kit form).

This way I can just pop the module into a circuit and program the Stamp using my existing software setup.

Again, thanks.

-Dominic

servello

westaust55 said...
Off topic in terms of USB conenction but . . .

looking at your schematic, you show the LED from +5Vdc (Vcc) to the junction of a resistor to a STAMP output AND GROUND.
While the resistor will protected the STAMP, by the schematic, the LED is across the full 5Vdc.

Remove the link from the junction of the LED and resistor to ground.

I presume that the circuit on the bread board omitted this connection.

I'm sorry, but I'm really new to circuits. Thanks for pointing out this error. Do you mean that the Blue Lead Wire (in the photo)should be removed? Is it possible to post a correct schematic? I don't mean to be a bother, but I truly want to learn.

-Dominic

westaust55

Okay, looking at the photo of the breadboard, what you have wired is different to the schematic

As it is, does your LED actually turn on and off? or is it permanently on?

In looking at the photo, it appears that you should remove the blue wire and move the resistor to where the blue wire was.
Then the STAMP output can turn the LED on (HIGH command) and off (LOW command)

See the rough attached part schematic for how the circuit will then be wired and drawn

servello

Yes, the LED does blink·ON and OFF as intended.

I think I'm starting to understand, and I'm going to try out your updated circuit.

I'll post the results a little later.

servello

Hi westaust55,

I re-did the circuit as suggested (replaced blue lead wire with the 470 ohm resistor) and it worked great. This circuit is·simpler and more clean (the lesser the components, the better).

Looking at it now, it makes much more sense. I learned a valuable lesson here. Thanks for the help.

- Dominic

Bill Chennault

Dominic--

It is neat that you are learning this stuff and found this forum to ask questions. I only began a few months ago and the people here CANNOT be beat.

If you haven't why don't you download Parallax's free "What's a Microcontroller?" If you want the printed version, it is inexpensive and well worth it.

--Bill

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You are what you write.

servello

If you haven't why don't you download Parallax's free "What's a Microcontroller?" If you want the printed version, it is inexpensive and well worth it.

Hi Bill,

Thanks for joining in on this thread. I have·learned much from reading·your posts here and I look forward to future correspondance. Regarding the "What's a Microcontroller?" material - I think it is simply the best introduction to electronics, programming and circuits there is. I mentioned in my original post that I am currently using the book and have completed the first four chapters.

Best,
Dominic

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- It's just a scratch, but it's a nasty scratch

Bill Chennault

Dominic--

Thank you very much for the compliment, but I obviously do not deserve it! I should have read your original post more carefully!

I hope you have fun and continue to ask questions of the guys on this forum that actually KNOW something.

--Bill

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You are what you write.

servello

Hey Bill,

You are too modest. You are a gentleman on these forums and you always do your best to be of help (especially to us real newbies).

I've finished up with the pushbuttons and am now moving along with the servos (I just did the first activity). I do not claim to understand everything from all the past activities, so although I am moving forward, I'm sure I'll be going back to earlier lessons to re-learn the material.

And, as you say, there are always you guys here to help out. And I look forward to future projects and forum participation.

- Dominic

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- It's just a scratch, but it's a nasty scratch