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Steve Joblin
08-17-2005, 04:41 AM
My new laptop does not have a Serial port, so I need a USB-to-Serial interface.· What is the difference between USB2SER (http://www.parallax.com/detail.asp?product_id=28024)·and the USB-RS232 (http://www.parallax.com/detail.asp?product_id=800-00030)·?

I assume they are the same, except that the USB2SER uses an in-line .1" standard header and that the USB-Rs232 uses a standard DB9 Serial.· Is this assumption correct?

Assuming that I am correct, does anyone make a single USB-to-Serial interface that also has the electronics on the Stamp (Q1, Q2, Q3, U3, resistors and capacitors) used for serial interfacing to the pre-programmed PIC?· Ideally, I would like my next project to just have the pre-programmed PIC, EEPROM and resonator and a four pin header (everything else would be on the "adapter board".

Thanks,

Steve

Chris Savage
08-17-2005, 06:57 AM
Steve,

·· The USB2SER cannot be used to program a BASIC Stamp.· The USB to Serial Adapter can.· Hope this helps.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Steve Joblin
08-17-2005, 07:20 AM
Thanks for the quick response Chris!· I am bit confused... what would the USB2SER be used for?

dandreae
08-17-2005, 07:29 AM
The USB2SER provides an easy way to interface a PC to a microcontroller. It bridges the PC.s USB port to logic-level RX and TX signals that can connect directly to a microcontroller.s I/O pins.

The reason that you can't use it to program a BASIC Stamp is because the BASIC Stamp expects an inverted signal and the USB2SER uses a straight signal.· Also it can't reset the stamp.



Dave


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Dave Andreae

Tech Support
dandreae@parallax.com (mailto:dandreae@parallax.com)
http://www.parallax.com



Post Edited (Dave Andreae (Parallax)) : 8/16/2005 11:48:33 PM GMT

knightofoldcode
08-17-2005, 02:33 PM
Steve Joblin said...
My new laptop does not have a Serial port, so I need a USB-to-Serial interface. What is the difference between USB2SER and USB-RS232?


I assume they are the same, except that the USB2SER uses an in-line .1" standard header and that the USB-Rs232 uses a standard DB9 Serial. Is this assumption correct?



Assuming that I am correct, does anyone make a single USB-to-Serial interface that also has the electronics on the Stamp (Q1, Q2, Q3, U3, resistors and capacitors) used for serial interfacing to the pre-programmed PIC? Ideally, I would like my next project to just have the pre-programmed PIC, EEPROM and resonator and a four pin header (everything else would be on the "adapter board".



Thanks,



Steve


As far as I know this is not available for purchase. However I am in the process of creating something really similiar. I have intentions of assembling my PCB's for runtime use, then popping in my EEProm into a socket on those PCB's, and be done. However I need a "programming" board. I've purchased a zif socket, and got the schematic going. It's basically a BS2 OEM schematic, however it's a little "ugly" in the fact that it still needs a BS2 itself to program the EEProm for it. But at the price of the BS2 Interpreter and all associated parts, it's only like $18 for those parts, so I'm just going to leave 'em in. Eseentially it'll be a BS2 OEM, but with supporting hardware such as, USB Connection for power, serial connection and power socket (for wall wart), Power LED, reset Button, etc.

I was thinking it'd be really slick if the only connection to the computer was a USB cable, but after looking at the required circuitry to make the FTDI chip work, I've changed my mind. That's alot of stuff. I'll just stick with the DB-9 Serial port. :) (6 Capacitors, 1 Ferrite Bead, 4 Resistors, 1 Crystal, FT232BM) Now that I really divuldge myself in it, it's not that bad, except for the fact that it'd HAVE to be surface mount. The FT232BM only comes in surface mount, I'm not sure about the ferrite bead....) You wouldn't be able to do it (wihtout alot of work) with a prototype board.

Also, something that makes me have to make sure you understand something.... The Pic is never programmed by anyone BUT Parallax. When you create a pBasic program, and download it to your stamp, you're actually sending it to the EEProm. So, on your runtime PCB you could have the Parallax Pic, and just take the EEProm to the PCB.

Knight.