I'm sorry...

Lord Steve

I need some hand-holding...

I have read that serial ports logic 1 is -3 to -25 volts and that logic 0 is +3 to +25 volts and I just might have that backwards.· I want to interface an SX to a PC serial port so I can watch pretty characters come up in hyperterminal.· This would be through a Parallax-sold USB-to-serial adapter.· What voltages do I need to worry about?· Do·I NEED this MAX232 thingie?· Yes, I did a forum search for "RS-232", and "pc serial port".

Chris Savage

MAX232 is the simplest way to go.· See details on our RS-232 AppMod, as the same concepts apply to the SX.

http://www.parallax.com/detail.asp?product_id=29120

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Chris Savage
Parallax Tech Support
csavage@parallax.com

Jon Williams

Since my serial port is tied up with the SX-Key, I usually use the USB2SER adapter for SX to PC comms.

http://www.parallax.com/detail.asp?product_id=28024

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Jon Williams
Applications Engineer, Parallax

Lord Steve

I have secured a MAX232.· It is NOT a MAX232A.· I only have 10uF electrolytic caps.· The datasheet says 1uF caps.· Can I use the 10uF caps, and if so, what behavior can i expect?

Chris Savage

Steve,

·· The Caps are used for the charge pumps.· I'm not certain what would happen, but if you're going to experiment, then by all means, experiment.·

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Chris Savage
Parallax Tech Support
csavage@parallax.com

Jon Williams

I'm pretty sure you need to use 1 uF caps -- that said, you can try the 10 uF but if they don't work you know why.

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Jon Williams
Applications Engineer, Parallax