Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? Especially is there any USART mode where one can send a string of bits longer than 10 bits without start/stop bits inbetween. Just like an ethernet frame or such?
PIC/AVR serial modes
Started by ●December 17, 2008
Reply by ●December 17, 20082008-12-17
On 17 Dec, 16:49, va...@silvtrc.org wrote:> Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? > > Especially is there any USART mode where one can send a string of bits longer > than 10 bits without start/stop bits inbetween. Just like an ethernet frame > or such?You can do whatever you like if you implement it yourself in software. Leon
Reply by ●December 17, 20082008-12-17
Leon <leon355@btinternet.com> wrote:>On 17 Dec, 16:49, va...@silvtrc.org wrote: >> Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? >> >> Especially is there any USART mode where one can send a string of bits longer >> than 10 bits without start/stop bits inbetween. Just like an ethernet frame >> or such?>You can do whatever you like if you implement it yourself in software.Sure, but the idea was to use a builtin hardware USART to reduce the cpu load.
Reply by ●December 17, 20082008-12-17
On Dec 17, 11:56=A0am, va...@silvtrc.org wrote:> Leon <leon...@btinternet.com> wrote: > >On 17 Dec, 16:49, va...@silvtrc.org wrote: > >> Are there other serial modes on PIC/AVR than standard RS-232 and SPI .=.?> > >> Especially is there any USART mode where one can send a string of bits=longer> >> than 10 bits without start/stop bits inbetween. Just like an ethernet =frame> >> or such? > >You can do whatever you like if you implement it yourself in software. > > Sure, but the idea was to use a builtin hardware USART to reduce the cpu =load.
Reply by ●December 17, 20082008-12-17
On Dec 17, 11:56=A0am, va...@silvtrc.org wrote:> Leon <leon...@btinternet.com> wrote: > >On 17 Dec, 16:49, va...@silvtrc.org wrote: > >> Are there other serial modes on PIC/AVR than standard RS-232 and SPI .=.?> > >> Especially is there any USART mode where one can send a string of bits=longer> >> than 10 bits without start/stop bits inbetween. Just like an ethernet =frame> >> or such? > >You can do whatever you like if you implement it yourself in software. > > Sure, but the idea was to use a builtin hardware USART to reduce the cpu =load. If you use a part that has an SPI interface with DMA, that will (kinda) give you what you want.
Reply by ●December 17, 20082008-12-17
On Wed, 17 Dec 2008 16:49:22 +0000 (UTC), valwn@silvtrc.org wrote:>Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? > >Especially is there any USART mode where one can send a string of bits longer >than 10 bits without start/stop bits inbetween. Just like an ethernet frame >or such?Some of the newer AVRs has a synchronous serial mode for the UART. One can program 5 bits per character mode, and send 2 in synchronous mode. Regards Anton Erasmus
Reply by ●December 18, 20082008-12-18
<valwn@silvtrc.org> wrote in message news:gibaii$29cm$1@news.ett.com.ua...> Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? > > Especially is there any USART mode where one can send a string of bitslonger> than 10 bits without start/stop bits inbetween. Just like an ethernetframe> or such?You can send any string of bits using the SPI interface. Meindert
Reply by ●December 18, 20082008-12-18
Meindert Sprang <ms@nojunkcustomorspamware.nl> wrote:><valwn@silvtrc.org> wrote in message news:gibaii$29cm$1@news.ett.com.ua... >> Are there other serial modes on PIC/AVR than standard RS-232 and SPI ..? >> >> Especially is there any USART mode where one can send a string of bits >longer >> than 10 bits without start/stop bits inbetween. Just like an ethernet >frame >> or such?>You can send any string of bits using the SPI interface.That work for open collector or RS485 bus too..? --
Reply by ●December 18, 20082008-12-18
<valwn@silvtrc.org> wrote in message news:gid73n$96s$1@news.ett.com.ua...> Meindert Sprang <ms@nojunkcustomorspamware.nl> wrote: > ><valwn@silvtrc.org> wrote in messagenews:gibaii$29cm$1@news.ett.com.ua...> >> Are there other serial modes on PIC/AVR than standard RS-232 and SPI..?> >> > >> Especially is there any USART mode where one can send a string of bits > >longer > >> than 10 bits without start/stop bits inbetween. Just like an ethernet > >frame > >> or such? > > >You can send any string of bits using the SPI interface. > > That work for open collector or RS485 bus too..?Of course. The SPI output is just a serial output, just like the UART TX output. You can add anything to that port, an open collector stage, a MAX485, anything. Meindert
Reply by ●December 18, 20082008-12-18
>> That work for open collector or RS485 bus too..?>Of course. The SPI output is just a serial output, just like the UART TX >output. You can add anything to that port, an open collector stage, a >MAX485, anything.SPI has three signal lines. My bus is only 1-bit "wide" (open collector). So somehow clock + data must be joined.