Splitting Serial

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How can I split a serial TX line.

What I want to do is connnect one AVR to a PC, but also send the TX from that AVR to the RX on another.

Can I simply split it? Can't be that simple I'm thinking.

Don't Let the smoke out!

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well you sill need a level converter between the PC and the AVR, but certainly you can connect multiple receivers to a single transmit pin. [the reverse cannot be said though, you cannot simply connect multiple transmitters to a single receiver]

Writing code is like having sex.... make one little mistake, and you're supporting it for life.

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Like normally in logic signals, single output pin (TX) can drive multiple input pins (RS232 tranceiver and AVR RX).

Not so normal, but I have successfully fed RS232 level signals to two RS232 receivers. Helps to monitor communication.

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Cool, I know I couldn't run multiple TX into a single RX - but wasn't sure about the other way around. Usually things I think are simple turn out to be d*m near impossible.

Thanks!

Don't Let the smoke out!

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Quote:
What I want to do is connnect one AVR to a PC, but also send the TX from that AVR to the RX on another.

Depend your bit rate you could use some transistor to implement that, split your TX signal, or use an analog switch.

Regards,
Brunomuw

Regards,

Bruno Muswieck

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brunomusw wrote:

Depend your bit rate you could use some transistor to implement that, split your TX signal, or use an analog switch.

Regards,
Brunomuw

We don't even know if he meant logic level or RS232 level signals or both. They cannot be mixed directly, however your transistor can in some cases work for this.

Logic level output can drive multiple logic level inputs just fine.

RS232 level output usually can drive more than one RS232 level input, but I would do it only for debug or hobby purposes, never on real products.

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Quote:
We don't even know if he meant logic level or RS232 level signals or both. They cannot be mixed directly, however your transistor can in some cases work for this.

Yes, I could let my ideia clear, I was talking about split it on TTL levels.

Quote:
RS232 level output usually can drive more than one RS232 level input, but I would do it only for debug or hobby purposes, never on real products.

Jeapael, you mean because of the input resistence of the receiver?

Regards,
Brunomusw

Regards,

Bruno Muswieck

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It would be True RS232 to True RS232, Baud rate 9600.

Is there another way to do it?

Don't Let the smoke out!

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Just connect TX to RX1 and RX2 like I debug stuff.

If you want to do it properly, first use one receiver convert RS232 levels to logic levels, and then use two transmitters to transmit to both PC and 2nd MCU.

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Jaasper take a look at daisy-chain scheme.

http://www.maxim-ic.com/appnotes...

Regards,
Brunomusw

Regards,

Bruno Muswieck

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Maybe this will help.

Cheers,

Ross

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Ross McKenzie ValuSoft Melbourne Australia