Yes, I can see 'rs485 v1.1'. The python code still works fine out of the box. C code Rx and Tx lines work OK but RTS still does nothing. When I exported the GPIO9 by hand, dmesg got: [ 222.055685] gpio_request: gpio-9 (RS485 TXE) status -16 [ 222.055730] omap_uart 481a8000.serial: Could not request GPIO 9 : -16
That means that 485 kernel support works. Without manually exporting it says just "[ 537.089146] rs485 v1.1" and does nothing. BUT now I've discovered something strange with logical level flags in struct serial_rs485, maybe I'm using different header or maybe I don't understand it correctly. When I changed the SER_RS485_RTS_AFTER_SEND to 0 and SER_RS485_RTS_ON_SEND to 0,* it started working fine*. That means, when sending data, RTS goes HIGH, after sending, it goes immediately LOW , that means, I expected setting ON_SEND to 1 and AFTER_SEND to 0, but with this setting it just changed from LOW to LOW. Thank you both again for Your valuable help. I'm satisfied now :-) Dne pondělí, 8. září 2014 19:12:55 UTC+2 Alexander Hiam napsal(a): > > > > Normally If you look at the log (dmsg) you should see a line rs485 >> something. It's a printk that I show when the ioctl work. >> > Right, it's 'rs485 v1.1'. If you see that in dmesg then the ioctl worked > and it's almost certainly a pinmux issue. > > >> And of course you have to configure the pin correctly = pin mode for TX, >> rx, gpio. >> Le 8 sept. 2014 17:27, <[email protected]> a écrit : >> >>> I've downloaded Robert C Nelson's code and run build_kernel.sh and >>> install_kernel.sh. I've controlled that sources are patched by rs485 patch. >>> BBB booted up normally and uname -r says that I am running new kernel. >>> But I don't have patched kernel headers. I have created serial.h header as >>> following: >>> 1 #include <linux/types.h> >>> 2 >>> 3 >>> 4 struct serial_rs485 { >>> 5 __u32 flags; /* RS485 feature flags */ >>> 6 #define SER_RS485_ENABLED (1 << 0) /* If >>> enabled */ >>> 7 #define SER_RS485_RTS_ON_SEND (1 << 1) /* Logical >>> level for >>> 8 RTS pin >>> when >>> 9 sending */ >>> 10 #define SER_RS485_RTS_AFTER_SEND (1 << 2) /* Logical >>> level for >>> 11 RTS pin >>> after sent*/ >>> 12 #define SER_RS485_RTS_BEFORE_SEND (1 << 3) >>> 13 #define SER_RS485_USE_GPIO (1 << 5) >>> 14 //#define SER_RS485_RX_DURING_TX (1 << 4) >>> 15 __u32 delay_rts_before_send; /* Delay before send >>> (milliseconds) */ >>> 16 __u32 delay_rts_after_send; /* Delay after send >>> (milliseconds) */ >>> 17 // __u32 padding[5]; /* Memory is cheap, new >>> structs >>> 18 __u32 gpio_pin; /* GPIO Pin Index */ >>> 19 __u32 padding[4]; /* Memory is cheap, new structs >>> 20 are a royal PITA .. */ >>> 21 }; >>> >>> >>> and used it in small example program: >>> #include <fcntl.h> >>> #include <termios.h> >>> #include <sys/ioctl.h> >>> #include <sys/types.h> >>> #include "serial.h" >>> //#include <include/uapi/linux/serial.h> >>> #include <stdio.h> >>> #include <unistd.h> >>> >>> int main() >>> { >>> int fd = open("/dev/ttyO4", O_RDWR | O_NOCTTY | O_NDELAY); >>> if (fd < 0) >>> { >>> perror("Error opening tty!"); >>> return 1; >>> } >>> >>> struct serial_rs485 rs485conf; >>> >>> rs485conf.flags |= SER_RS485_ENABLED; >>> >>> rs485conf.flags |= SER_RS485_USE_GPIO; >>> rs485conf.gpio_pin = 9; >>> rs485conf.flags |= SER_RS485_RTS_ON_SEND; >>> rs485conf.flags &= ~(SER_RS485_RTS_AFTER_SEND); >>> rs485conf.delay_rts_before_send = 0; >>> rs485conf.delay_rts_after_send = 0; >>> >>> if (ioctl (fd, TIOCSRS485, &rs485conf) < 0) >>> { >>> perror("Bad ioctl"); >>> } >>> >>> struct termios ttyc; >>> tcgetattr(fd, &ttyc); >>> >>> cfsetospeed(&ttyc, B9600); >>> cfsetispeed(&ttyc, B9600); >>> ttyc.c_cflag &= ~CRTSCTS; >>> ttyc.c_cflag |= CS8 | CLOCAL | CREAD; >>> ttyc.c_cflag |= CRTSCTS; >>> ttyc.c_cc[VMIN] = 1; >>> ttyc.c_cc[VTIME] = 5; >>> tcsetattr(fd, TCSANOW, &ttyc); >>> >>> char data = 0xAA; >>> >>> int i = 0; >>> while(i < 10000) >>> { >>> if(write(fd, &data, 1) < 1) >>> { >>> perror("Error sending char"); >>> break; >>> } >>> >>> i++; >>> } >>> >>> if (close (fd) < 0) >>> { >>> perror("Error closing tty!"); >>> return 1; >>> } >>> >>> >>> return 0; >>> } >>> but RTS pin stays still LOW. >>> >>> >>> Dne čtvrtek, 4. září 2014 21:51:58 UTC+2 Mickae1 napsal(a): >>>> >>>> In the Debian image from Robert C Nelson, the patch rs485 is already >>>> included. >>>> Le 4 sept. 2014 20:57, <[email protected]> a écrit : >>>> >>>>> Thank you for your answers. The python code is working perfectly. >>>>> I need to use it in greater C project though. So I am compiling new >>>>> kernel including RS485 patch. I have tried >>>>> /opt/scripts/tools/update_kernel.sh >>>>> hoping that it includes the RS485 patch ...unsuccessfully. >>>>> I am now following steps from http://jkridner.wordpress.com/ >>>>> 2014/06/04/yet-another-set-of-notes-on-building-beaglebone-kernel/ >>>>> >>>>> Dne středa, 3. září 2014 17:57:53 UTC+2 [email protected] napsal(a): >>>>>> >>>>>> Hello, >>>>>> I'm writing an app for BeagleBoneBlack running debian >>>>>> (3.8.13-bone50). I would like to use UART4 to communicate with RS485 >>>>>> transmitter over P9.24(UART4 Tx), P9.26(UART4 Rx) and P8.33 (UART4 RTS). >>>>>> I've disabled HDMI and enabled overlays BB-UART4 and BB-UART4-RTSCTS >>>>>> >>>>>> cat /sys/devices/bone_capemgr.9/slots >>>>>> 0: 54:PF--- >>>>>> 1: 55:PF--- >>>>>> 2: 56:PF--- >>>>>> 3: 57:PF--- >>>>>> 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G >>>>>> 5: ff:P-O-- Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI >>>>>> 6: ff:P-O-- Bone-Black-HDMIN,00A0,Texas Instrument,BB-BONELT-HDMIN >>>>>> 7: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-UART4 >>>>>> 10: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-UART4-RTSCTS >>>>>> >>>>>> cat /proc/tty/driver/OMAP-SERIAL >>>>>> serinfo:1.0 driver revision: >>>>>> 0: uart:OMAP UART0 mmio:0x44E09000 irq:72 tx:345 rx:0 RTS|CTS|DTR|DSR >>>>>> 4: uart:OMAP UART4 mmio:0x481A8000 irq:45 tx:61355 rx:1 brk:1 RTS|DTR >>>>>> |DSR >>>>>> >>>>>> >>>>>> RS485 transmitter is connected through RS485-USB converter to PC. >>>>>> When I run screen /dev/ttyO4 9600 +crtscts and periodicaly write some >>>>>> data >>>>>> to it, PC receives it properly, but RTS line stays constantly low (I'm >>>>>> using scope on Tx and RTS lines). >>>>>> I've also tried to write simple C program, using *struct >>>>>> serial_rs485. *When I write some data over this program, I got >>>>>> response: *Resource temporarily unavailable* and dmesg says >>>>>> *omap_uart 481a8000.serial: Must use GPIO for RS485 Support. *When I >>>>>> tried to use: >>>>>> struct serial_rs485 rs485conf; >>>>>> rs485conf.flags |= SER_RS485_USE_GPIO; >>>>>> rs485conf.gpio_pin = GPIO0_9; >>>>>> >>>>>> I got error from gcc that it does not know those macros: >>>>>> ‘SER_RS485_USE_GPIO’ was not declared in this scope >>>>>> rs485conf.flags |= SER_RS485_USE_GPIO; >>>>>> ‘struct serial_rs485’ has no member named ‘gpio_pin’ >>>>>> rs485conf.gpio_pin = GPIO0_9; >>>>>> ‘GPIO0_9’ was not declared in this scope >>>>>> rs485conf.gpio_pin = GPIO0_9; >>>>>> >>>>>> Could somebody help me? I have no more ideas. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>> 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/d/optout. >>>>> >>>> -- >>> 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/d/optout. >>> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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