Output multiple RS232 data?

johnboyington

This may be a noob question but here is what I need to accomplish.
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I need to send short messages to several serial LCD screens that use RS232 rx @ a 2400 baud rate.
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Can multiple I/O pins on a basic stamp be configured to transmit separate RS232 data?

If a basic stamp can't do this does anyone have a cheap sugestion?
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Thanks in advance.
John

Chris Savage

John,
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·· The BASIC Stamp should be able to do this no problem.· The only thing you’re going to have to do is determine whether or not the I/O pin can drive the RS-232 input without a line driver.· You would need to use inverted baud mode to do this.· This is assuming you are only sending data to the LCD and not receiving data back as well.· I hope this helps.· Take care.

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Chris Savage
Parallax Tech Support

allanlane5

Yup, every SEROUT statement can use a different pin and a different baud rate. And any and all I/O pins can be used in this way. Pretty convenient and powerful, really.

The only drawback is that there is not really a UART on each pin -- so the BS2 can send data, or listen to data, but it can't do both at the same time. Just be aware.

johnboyington

Thanks guys, that's what I needed to know.

FORD

I use 3 rs232 ports on our system.

First I always·use the programming port (serout or serin,·pin 16) because it already has the rs232 driver.

Then I use a MAX233 ttl/rs232 converter on 4 other pins to use as 2 more serial ports, 2·* rx and 2·* tx.

The MAX233 is a bit expensive, but it doesnt need any external caps, and it has 2 ports in it.

Using the stamp programming port saves you fitting a serial driver if you only needed 1 port.

Cheers,
Chris