How to increase the number of RS232 available on a microcontroller?

[leoren_tm]

Any scheme on how increase the number of RS232 available on a micro controller? like multiplexing.... pls suggest any IC to use

 

[drbizzarow]

EXTEND RS232

what kind of multiplexing you need ?? HW or SW ???
like through SW you can use any PIC IO port as serial port ..... but 1 at a time

 

[MAK-1]

EXTEND RS232

For multiple HW RS232 multiplexing use external multiplexer.

 

[amol_shah]

Re: EXTEND RS232

use bit banging technique
https://www.dnatechindia.com/index.php/Tutorials/8051-Tutorial/Bit-Banging.html

 

[laktronics]

Re: EXTEND RS232

Hi,
If your Micro has sufficient idle time bit banging can be used. Otherwise you have to interface UART Chips along with RS232 drivers.

Regards,
Laktronics

 

[leoren_tm]

Re: EXTEND RS232

what kind of multiplexing you need ?? HW or SW ???
like through SW you can use any PIC IO port as serial port ..... but 1 at a time

what is HW and SW? anyway ill be using 8051 micro

Added after 2 minutes:

For multiple HW RS232 multiplexing use external multiplexer.

external? what do you mean by that? i was thinking og multiplesing my UART or maybe tru 232 signal. im asking if this is efficient.

Added after 2 minutes:

use bit banging technique
https://www.dnatechindia.com/index.php/Tutorials/8051-Tutorial/Bit-Banging.html

i think its not a good application

this is quite a tedious process and puts too much load the Micro controller processing.

and its by software....maybe it would be easy if ill let the hardware do it/

Added after 1 minutes:

Hi,
If your Micro has sufficient idle time bit banging can be used. Otherwise you have to interface UART Chips along with RS232 drivers.

Regards,
Laktronics

didnt get your point..about RS232..?? im thinking of MAX232, it just convert the TTL to RS232 signal.

Added after 2 minutes:

AH!! what i mean on my post is to virtually increase my UART.

 

[drbizzarow]

EXTEND RS232

HW=hardware and SW=software by the if u r using 8051 controller then forget SW option

 

[penoy_balut]

EXTEND RS232

a single uart can be up to 16 by using mux/demux like CD4067, additional pins are required for addressing

 

[leoren_tm]

Re: EXTEND RS232

a single uart can be up to 16 by using mux/demux like CD4067, additional pins are required for addressing

yah as i mention earlier..but did you try using it?(theoriticaly it will work)

 

[davidgrm]

Re: EXTEND RS232

Software UART can be done on 8051. In fact the boolean processor makes this very efficient. The other alternative is to use a multi drop network such as rs485

 

[leoren_tm]

Re: EXTEND RS232

Software UART can be done on 8051. In fact the boolean processor makes this very efficient. The other alternative is to use a multi drop network such as rs485

i think your making it complicated..pls explain

 

[davidgrm]

Re: EXTEND RS232

Not sure which of my two suggestions is making it more complicated. You have not stated exactly what you are trying to achieve. If you just want to communicate between a lot of micro's you can use rs485. This will allow distances of over a kilometre. You can connect many systems together on an rs485 network and it is fairly simple to use.
My comment about the 8051 was just in response to drbizzarow's comment regarding 8051. The 8051 has a hardware uart and can support quite a few soft uarts. Atmel have an app note which has 8 soft uarts plus a hardware uart all working simultaneously at 9600 baud.

 

[aNdreiBuuu]

Re: EXTEND RS232

**broken link removed**

...but is better to choose a controller with 4 UARTs for example...
//a

 

[leoren_tm]

Re: EXTEND RS232

Not sure which of my two suggestions is making it more complicated. You have not stated exactly what you are trying to achieve. If you just want to communicate between a lot of micro's you can use rs485. This will allow distances of over a kilometre. You can connect many systems together on an rs485 network and it is fairly simple to use.
My comment about the 8051 was just in response to drbizzarow's comment regarding 8051. The 8051 has a hardware uart and can support quite a few soft uarts. Atmel have an app note which has 8 soft uarts plus a hardware uart all working simultaneously at 9600 baud.

can you show me the application note?
anyway...want i want is..to communicate to many micro usig UART...as an example a multiplexer...distanvce is just a common application for rs232/