PropPlug documentation
Harley
Posts: 997
I've just ordered a PropPlug, but haven't found any documentation on it to design to.
What caveats are there to designing a pcb to accomodate this part?____
1. What clearance on the back side is required, as it appears to be close to a board is the header pins are parallel to the PropPlug?___
2. Can it be 'hot plugged' or is power required to be turned off when plugging in?___
3. Can the Tx/Rx lines be used for anything else after downloading?___ (If so, this frees up those two pins for other uses. I understand the Prop can be used, but does the Tx signal hold the line solidly?___)
4. Is it desirable to mount the PropPlug perpendicular to the board (using a straight, rather than right-angle header)?___
5. Does any documentation come with the PropPlug?___ (If so, I suppose I can wait until the part arrives in several days.)
6. (To Parallax[noparse]:)[/noparse] Is the part so new, this is why no documentation exists on the web site?___
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Harley Shanko
h.a.s. designn
Post Edited (Harley) : 11/7/2006 3:49:50 AM GMT
What caveats are there to designing a pcb to accomodate this part?____
1. What clearance on the back side is required, as it appears to be close to a board is the header pins are parallel to the PropPlug?___
2. Can it be 'hot plugged' or is power required to be turned off when plugging in?___
3. Can the Tx/Rx lines be used for anything else after downloading?___ (If so, this frees up those two pins for other uses. I understand the Prop can be used, but does the Tx signal hold the line solidly?___)
4. Is it desirable to mount the PropPlug perpendicular to the board (using a straight, rather than right-angle header)?___
5. Does any documentation come with the PropPlug?___ (If so, I suppose I can wait until the part arrives in several days.)
6. (To Parallax[noparse]:)[/noparse] Is the part so new, this is why no documentation exists on the web site?___
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Harley Shanko
h.a.s. designn
Post Edited (Harley) : 11/7/2006 3:49:50 AM GMT
Comments
2. Yes
3. I'll have to ask
4. It doesn't matter either works
5. Soon it will be availible for download
6. Yes
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
Hope there is notice when the PropPlug download is available.
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Harley Shanko
h.a.s. designn
To answer question 3, we strongly recomend not using the Prop Plug's Tx·connection (Propeller's Pin 31) for another purpose. This·line is driven high by the Prop Plug. There is a 150 Ohm resistor this is fed through, but it is not rated for very much current. You can force it low if you include a 220-330 Ohm resistor in the signal path, but like I said we do not recomend doing this. The·Prop Plug's Rx line can be used for other purposes, this is weakly pulled high by the Prop Plug.
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
Our web staff tells me that the PropClip/PropPlug documentation will be posted on the product pages today.·We apologize for the delay.
-Stephanie Lindsay
Editor, Parallax Inc.
I will use two other pins for FullDuplexSerial i/f to avoid driving into the PropPlug circuitry. I found the same problem with the PropSTICK; Prop manual says the pins are free for user, but the MAX chip is driving its output solidly. That made it impossible to tell if FullDuplexSerial or my program was even running.
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Harley Shanko
h.a.s. designn
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Paul Baker
Propeller Applications Engineer
Parallax, Inc.
The only PC i/f is during programming.
Using another pair of pins for serial i/f w/ the other board, there are still several pins remaining on both Props. Fingers crossed that they can remain unused when done programming.
Again, many thanks for assistance with the Propeller and PropPlug questions.
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Harley Shanko
h.a.s. designn
Sometimes you can 'fudge' an open collector output with nothing more than a diode and resistor.
This even works when the supply voltages are different.· The GND or Vss must be shared however.
o--/\/\---> Pullup supply | | From driven output device >------|<----o---------> Output acts like an Open collector▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Beau Schwabe
IC Layout Engineer
Parallax, Inc.
Post Edited (Beau Schwabe (Parallax)) : 11/7/2006 10:27:05 PM GMT
http://www.parallax.com/detail.asp?product_id=32201
Btw, I'd guess the pull-up R is on the wrong side of the diode. Or, was this a 'test'? Hah!
Thanks, Beau, for an alternative I'd not thought of; just in case I/O becomes tight.
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Harley Shanko
h.a.s. designn
Are you using a browser that doesn't show monospaced text? (My iMac is that way using Opera). Without it, the pullup does appear on the wrong side of the diode. But this is an illusion wrought by the text that precedes the diode on the fourth line of the schematic.
-Phil
I note on pg.3 though, the titles of PropClip and PropPlug are switched. If not wrong, I may have ordered the wrong part.
Thanks.
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Harley Shanko
h.a.s. designn
I can imagine the upper three lines should connect to the anode side, then. Makes sense then. Dang browsers not doing WYSIWYG. I didn't realize such until I did some web site design (for self). Can be quite a difference between browsers; even IE on Mac or PC. My formatting was not right depending on whether viewed from Mac or PC. Wish the industry could get it right; suppose there isn't a good spec to actually design to.
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Harley Shanko
h.a.s. designn
True, so invert the data with a transistor and wire the transistor with an open collector configuration.
How fast do you want to go?··A 1K - 10K resistor should be fine
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
Fortunately I have some spare pins on the Prop. But a good idea to have just in case later happend.
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Harley Shanko
h.a.s. designn
-Stephanie Lindsay
Editor, Parallax Inc.··
WOW! I didn't visualize how tiny they are. Cool pcb design
And the retractable cable rather matches it. The actual 'cable' is so thin; hope there is good longevity for it. Probably NOT a good idea to 'play' with it and listen to the ratchet clicks.
I printed out the document on the PropPlug. For some reason there was no text on it (except for titling at bottom). Am I missing something?____
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Harley Shanko
h.a.s. designn
I can attest that the pdf I uploaded has text on it!· Can you read it properly on the screen, but the text won't print?·Can you print as an image?···I have had a problem like that crop up just recently,·for us it is a situation where a new printer does not play well with certain fonts, and perhaps not all fonts embedding in the document properly.· However, this particular document is not one where I have had problems!
I will try a few tricks and tests to see what is up with this particular doc.· If you are willing to run a test-print for me, please email me!
Edited to add: Version 1.2 of this document will be uploaded to our website shortly.· It is an Adobe Acrobat 6-generated document with embedded TrueType fonts. Harley, please email me if it does not print properly.
Stephanie Lindsay
editor@parallax.com
Post Edited (Steph Lindsay (Parallax)) : 11/9/2006 7:01:10 PM GMT
Some other possible errata:
Page 4 is entirely blank, save for the footer (although that may have been intentional).
The schematic on page 6 is for a different product. It looks more like one for a USB-to-RS232 adapter; but even then, there are some errors in it. (FTDI chip is mislabled as "BM" instead of "R"; DB9 pin directions are reversed; ATN circuit is ... well, I can't make heads or tails of it. The caps on the DB9 probably don't belong there, and I doubt that DTR would be AC-coupled for an RS232 adapter -- though it would be for something like a PropPlug.)
-Phil
Stephanie Lindsay