I am looking for an PIC with three UART ports if such a thing exists. I have two UART inputs and I want to output a single UART output. I've seen plenty of ICs with 2 UART ports, but I have yet to find one with three. I typically use microchip ICs, but I am open to any brand as long as it would do the trick and has a good C compiler. How would a situation like this be handled in modern electronics? I am a student and we typically would solve something like this with a MUX. However, 1) it seems pretty "primitve" for today's electronics - are these still used? and 2) I would like to use all three UART ports at the same time. I was thinking of two ICs, but with only 2 UARTs that wouldn't solve the problem. The only other idea I could come up with would be to have an IC to store the data from each UART input to a memory IC. A third IC would then read/write from the shared memory and output a single UART output. Is there anything simple that would solve my problem? I am a software guy and am not very good with hardware. Any advice or even google search words would be appreciated. Thanks for the help.
UART x3
Started by ●November 17, 2007
Reply by ●November 17, 20072007-11-17
On Nov 17, 12:51 pm, "jonathan03" <jm_2003_2...@yahoo.com> wrote:> I am looking for an PIC with three UART ports if such a thing exists. I > have two UART inputs and I want to output a single UART output. I've seen > plenty of ICs with 2 UART ports, but I have yet to find one with three. I > typically use microchip ICs, but I am open to any brand as long as it > would do the trick and has a good C compiler. > > How would a situation like this be handled in modern electronics? I am a > student and we typically would solve something like this with a MUX. > However, 1) it seems pretty "primitve" for today's electronics - are these > still used? and 2) I would like to use all three UART ports at the same > time. > > I was thinking of two ICs, but with only 2 UARTs that wouldn't solve the > problem. The only other idea I could come up with would be to have an IC > to store the data from each UART input to a memory IC. A third IC would > then read/write from the shared memory and output a single UART output. > > Is there anything simple that would solve my problem? I am a software guy > and am not very good with hardware. Any advice or even google search words > would be appreciated. Thanks for the help.If the bitrate isn't too high, you could bitbang one of the UARTs. The output would be the easiest. You can use a timer interrupt programmed at the exact length of a bit, and keep a small state machine to sequentially write the bits.
Reply by ●November 17, 20072007-11-17
On Sat, 17 Nov 2007 05:51:12 -0600, "jonathan03" <jm_2003_2008@yahoo.com> wrote:>I am looking for an PIC with three UART ports if such a thing exists. I >have two UART inputs and I want to output a single UART output. I've seen >plenty of ICs with 2 UART ports, but I have yet to find one with three. I >typically use microchip ICs, but I am open to any brand as long as it >would do the trick and has a good C compiler.Atmel AVR ATMega 640/1280/2560 has four hardware UARTs. The programming architecture is much more straigghtforward and C friendly than the PIC's with their crippled architecture. A decent gcc port does exist, and there are also some good commercial tools (Imagecraft, Codevision, IAR (expensive!!!)). Mit freundlichen Gr��en Frank-Christian Kr�gel
Reply by ●November 17, 20072007-11-17
On Sat, 17 Nov 2007 05:51:12 -0600, "jonathan03" <jm_2003_2008@yahoo.com> wrote:>I am looking for an PIC with three UART ports if such a thing exists. I >have two UART inputs and I want to output a single UART output. I've seen >plenty of ICs with 2 UART ports, but I have yet to find one with three. I >typically use microchip ICs, but I am open to any brand as long as it >would do the trick and has a good C compiler. > >How would a situation like this be handled in modern electronics? I am a >student and we typically would solve something like this with a MUX. >However, 1) it seems pretty "primitve" for today's electronics - are these >still used? and 2) I would like to use all three UART ports at the same >time. > >I was thinking of two ICs, but with only 2 UARTs that wouldn't solve the >problem. The only other idea I could come up with would be to have an IC >to store the data from each UART input to a memory IC. A third IC would >then read/write from the shared memory and output a single UART output. > >Is there anything simple that would solve my problem? I am a software guy >and am not very good with hardware. Any advice or even google search words >would be appreciated. Thanks for the help. >If the baudrate is sensible, and depending on other interrupt activity, a soft UART is easy enough, especially for TX only. Creative use of a timer compare output might also be possible if interrupt jitter is a problem. .
Reply by ●November 17, 20072007-11-17
On Sat, 17 Nov 2007 05:51:12 -0600, "jonathan03" <jm_2003_2008@yahoo.com> wrote:>I am looking for an PIC with three UART ports if such a thing exists. I >have two UART inputs and I want to output a single UART output. I've seen >plenty of ICs with 2 UART ports, but I have yet to find one with three. I >typically use microchip ICs, but I am open to any brand as long as it >would do the trick and has a good C compiler.As I read this, you are saying that two of your serial signals are receive-only, while the third is transmit-only. Can you not use UART1 to receive one receive only signal and send the transmit-only signal, and use UART2 to receive the second receive-only signal? On most UARTs that I've used, the transmit and receive sections are independent, except for baud rate. -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca