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???
03/10/08 08:34
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 		 #152061 - Two RS232 devices
Responding to: ???'s previous message
I am assuming that your LCD is an RS232 device. I have no experience with them, but if you can run it as a a simple receiver with no handshake.

You would just have one TX output for your printer from the UART at 9600 baud. And a different pin as a software UART TX to your LCD. With no handshake, you will have to ensure that you do not write to the LCD too fast.

I initially read your message as adding a regular LCD module which needs at least six pins to drive as 4bit write-only. You could share those pins (except for the Enable line) with some other device but NOT your printer.

David.

List of 32 messages in thread
TopicAuthorDate
One RS232 port and two devices            01/01/70 00:00      
   Almost certainly not!            01/01/70 00:00      
      neither one talks back            01/01/70 00:00      
         Soft-UART ?            01/01/70 00:00      
         Simplex            01/01/70 00:00      
            responses            01/01/70 00:00      
               The beaty of the 8051            01/01/70 00:00      
                  why all this about bit-banging            01/01/70 00:00      
               Bit banging UART TX.            01/01/70 00:00      
                  Easy to get wrong.            01/01/70 00:00      
                     Point taken, but you can calculate delay.            01/01/70 00:00      
                        Depends on compiler/etc...            01/01/70 00:00      
                           Don't use HLL!            01/01/70 00:00      
                              Cycle counting.            01/01/70 00:00      
                                 Fundamental flaw            01/01/70 00:00      
                              Not an Absolute....            01/01/70 00:00      
                                 RE: Never is a strong word            01/01/70 00:00      
                                    ... and            01/01/70 00:00      
                              assembly verses HLL            01/01/70 00:00      
                           Use a Timer IRQ to set the soft baudrate            01/01/70 00:00      
                              Surprise.            01/01/70 00:00      
                                 High risk            01/01/70 00:00      
                                    Straying into fantasy.            01/01/70 00:00      
                                       Not so fantastic?            01/01/70 00:00      
                  Resistance is too high            01/01/70 00:00      
                  Another reason why this is not so easy...            01/01/70 00:00      
               Timescales            01/01/70 00:00      
      message formatting            01/01/70 00:00      
         Try it now            01/01/70 00:00      
            It's OK now, thanks.            01/01/70 00:00      
   Two RS232 devices            01/01/70 00:00      
      the LCD display            01/01/70 00:00      

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