I have a problem with interfacing two serial port with 8051 microcontroller. I have to use bar code reader and RF reciver and transmitter which both of them interfaced serially. I am thinking to add an ic to controller these to serial ports, but I don't know which type of IC I should used!! could any one help me, please?
Thanks,
Thanks Eric for your comments! Devices like LTC1387 will do the job. When a channel in high impedance on RS232 side, shoritng RX (at TTL) may not give you chance for smoke. Else it is simple to build a switch to isoalte TTL side, with old style MAX232 device.
Thanks Eric for your comments! Devices like LTC1387 will do the job ... as far as I can see there is no disable of the (TTL level) Rx output and it IS push-pull. Thus parallelling two WILL give smoke.
Erik
continuing: why not just use an OR gate?
Thanks for every body who try to help me.
yes, I was thinking to use an OR gate...
thanks a lot
So now you're discounting all the reasons that have been repeatedly explained to you why trying to bodge this onto a single UART is a Really Bad Idea!
Don't do it!
You will compromise the functionality of your project, you will make your design & development harder, and you are unlikely to save any cost on the hardware - but may well make it more expensive!
Why on earth would you do that?!
Thank you Andy
unfotunitly I searched about 8051 with 2 serial port, but the company didn't deliverd the part the UAE and other companies the product is out of stock....
So what can I do????????????/ I should look for alternative!!!!
digi-key http://www.digikey.com/ ship all over the world and I believe, so does Mouser and others