Oops, good point. That's what I get for skimming ;) With that requirement, what about multiplexing some of your other pins? Use a serial to parallel shift register or whatever they're called, that way with just 2 or 3 pins you can output or input 8. As long as you don't need to do anything weird, it should work. The data into a LCD or something else with 8 data input pins would work just fine this way. -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Mitch Berkson Sent: Friday, June 08, 2001 7:19 PM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [PIC]:Possible to use USART for RX and have TX as general purpose I/O? I won't be able to use the USART receiver portion if the USART is disabled. Mitch Berkson ----- Original Message ----- From: "Michael Cook" To: Sent: Friday, June 08, 2001 6:52 PM Subject: Re: [PIC]:Possible to use USART for RX and have TX as general purpose I/O? > It should be perfectly possible. If you don't enable the USART, they > should be general IO pins. If memory serves me, the USART is DISABLED > by default, so as long as you don't touch the registers you should be > fine. > > -----Original Message----- > From: pic microcontroller discussion list > [mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Mitch Berkson > Sent: Friday, June 08, 2001 5:01 PM > To: PICLIST@MITVMA.MIT.EDU > Subject: [PIC]:Possible to use USART for RX and have TX as general > purpose I/O? > > > With a 16F877, I would like to use the USART to receive asynchronous > data but use the TX pin as a general purpose I/O. After having tried > various permutations of TXEN, SPEN and tristating the TX pin or not, I > suspect that this is not possible. > > Disabling the entire USART when I want to use the TX as an output is > not an option because receive data can arrive at any time. A software > USART is also not an option. > > Thanks for any help. > > Mitch Berkson > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.