Hi Mike, I want to send the string of binary data, like 10001111 or 11110011 etc., and I expect to see HIGH and LOW on Oscilloscope.
When I use command set "echo -n \x01 > /dev/ttyO4" i can see on oscilloscope <https://lh5.googleusercontent.com/-SFyPNhrmt1Q/UpW8pMOL1QI/AAAAAAAAAIc/vXwys02_w9k/s1600/TEK00001.PNG> "echo -n \x1001 > /dev/ttyO4"<https://lh3.googleusercontent.com/-FM4duvgj-Js/UpW87M2poNI/AAAAAAAAAIk/NiFsI8K2u98/s1600/TEK00002.PNG> It is still in ascii, is there a way how to get it to work and send standard binary string , because my device needs CMOS/TTL logic. On Tuesday, 26 November 2013 19:53:44 UTC+1, Mike Bremford wrote: > > I'm really not sure this question at all. UART4 Tx a single wire which is > high by default. Put a multimeter on the uart4tx pin to confirm this. If > you send data to it then it goes out in blocks of N bits (N normally being > 10 - start bit, 8 data bits, stop bit), then returns to the default state > of high until the next transmission. > http://en.wikipedia.org/wiki/Asynchronous_start-stop > > Do you want to send binary data bit-by-bit, as in: write 1 to it, the pin > goes high, write 0 and the pin goes low? Then that's not what a UART does - > sounds like GPIO to me. > > Do you want to send the byte 0, as in: start bit, 8 x low bits, stop bit? > Then "echo -n \x00 > /dev/ttyO4" should do it. But much easier to do this > in C (or any other language) as the ttyO4 is just a file: open it, set it > up as a TTY (in C with functions tcsetattr, cfmakeraw etc), then write the > zero byte to the stream. > > > On 26 November 2013 14:42, Andrei <[email protected] <javascript:>>wrote: > >> Hello Rod, >> >> Thanks you for the help on this, was really helpful. >> But do you know how can I send the binary instead of ascii? (Do I need >> to put maybe prefix of SB before the value to send binary?) >> >> After many unsuccessful attempts of sending binary over UART, I'm >> looking at possibility to change the UART MODE described in *TI AM335x >> ARM A8 Microprocessors technical reference manual , *maybe this will >> allow me to send the binary then. >> >> >> For my project, the transceiver that I wan to connect to UART needs >> CMOS/TTL logic. >> >> >> On Monday, 25 November 2013 21:05:16 UTC+1, rod calabio wrote: >>> >>> Andrei >>> >>> ascii for "1" is 00110001 >>> ascii for Line feed is 00001010 >>> >>> so you will get >>> st=0 >>> d0 = 1 >>> d1 = 0 >>> d2 = 0 >>> d3 = 0 >>> d4 = 1 >>> d5 =1 >>> d6 = 0 >>> d7 =0 >>> sp = 1 >>> st = 0 >>> d0 = 0 >>> d1 = 1 >>> d2 = 0 >>> d3 = 1 >>> d4 - d7 =0 >>> sp = 1 >>> idle = 1 >>> >>> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
