| 107 | | || Laguna || GW2380/2/3 || UART0 || ttyS0 || console: 3.3V TTL JTAG J2 / 3.3V TTL J4 || |
| 108 | | || || || UART1 || ttyS1 || GPS || |
| 109 | | || || || UART2 || ttyS2 || UART: 3.3V TTL J8 || |
| 110 | | || || GW2387 || UART0 || ttyS0 || console: 3.3V TTL JTAG J3/J7 / RS232 J13 || |
| 111 | | || || || UART1 || ttyS1 || RS232 J13 / 3.3V TTL J7 || |
| 112 | | || || || UART2 || ttyS2 || GPS || |
| 113 | | || || GW2388 || UART0 || ttyS0 || console: 3.3V TTL JTAG J8 / RS232 J21 || |
| 114 | | || || || UART1 || ttyS1 || RS232 J21 || |
| 115 | | || || || UART2 || ttyS2 || GPS || |
| 116 | | || || GW2391 || UART0 || ttyS0 || console: 3.3V TTL JTAG J1 / RS232 J15 || |
| 117 | | || || || UART1 || ttyS1 || RS232 J15 || |
| 118 | | || || || UART2 || ttyS2 || GPS || |
| 119 | | || || |
| 625 | | [=#rs485-example] |
| 626 | | === RS485 without TIOCSRS485 driver support |
| 627 | | If a board connects RTS, DTR, or a gpio to TX-Enable but does not support the TIOCSRS485 you can alter your code to enable/disable the TX-Enable as needed. |
| 628 | | |
| 629 | | Note that if a driver supports TIOCSRS485 (in other words it handles the assertion/de-assertion of TXEN in the driver) this is preferred over using tcdrain() to determine when the FIFO is empty as tcdrain() can have considerable latency at small transmit sizes. |
| 630 | | |
| 631 | | Example: |
| 632 | | {{{#!c |
| 633 | | /** write_file - write to a file |
| 634 | | * @param str to write |
| 635 | | * @param fname to write to |
| 636 | | * |
| 637 | | * This is used to set/configure GPIO's via the sysfs interface to gpio class |
| 638 | | */ |
| 639 | | int write_file(const char* str, const char* fname) |
| 640 | | { |
| 641 | | FILE *file; |
| 642 | | int ret = -EIO; |
| 643 | | |
| 644 | | file = fopen(fname, "w"); |
| 645 | | if (file) { |
| 646 | | ret = fprintf(file, "%s\n", str); |
| 647 | | if (ret <= 0) |
| 648 | | ret = -EIO; |
| 649 | | fclose(file); |
| 650 | | return 0; |
| 651 | | } |
| 652 | | return ret; |
| 653 | | } |
| 654 | | |
| 655 | | |
| 656 | | /** assert_tx - enable/disable TX on a device |
| 657 | | * @param dev - serial device |
| 658 | | * @param enable - enable or disable |
| 659 | | * @returns 0 on success otherwise error |
| 660 | | */ |
| 661 | | int assert_tx(int fd, const char *txen, unsigned char enable) |
| 662 | | { |
| 663 | | char str[64]; |
| 664 | | int t; |
| 665 | | |
| 666 | | if (!txen) |
| 667 | | return 0; |
| 668 | | |
| 669 | | printf("%sasserting %s\n", (enable)?"":"de-", txen); |
| 670 | | if (strcasecmp(txen, "DTR") == 0) { |
| 671 | | // assert DTR on enable, de-assert on disable |
| 672 | | t = TIOCM_DTR; |
| 673 | | return ioctl(fd, (enable)?TIOCMBIC:TIOCMBIS, &t); |
| 674 | | } else if (strcasecmp(txen, "RTS") == 0) { |
| 675 | | // assert RTS on enable, de-assert on disable |
| 676 | | t = TIOCM_RTS; |
| 677 | | return ioctl(fd, (enable)?TIOCMBIC:TIOCMBIS, &t); |
| 678 | | } else if (strncasecmp(txen, "gpio", 4) == 0) { |
| 679 | | t = atoi(txen + 4); |
| 680 | | sprintf(str, "/sys/class/gpio/gpio%d/value", t); |
| 681 | | write_file((enable)?"1":"0", str); |
| 682 | | } |
| 683 | | |
| 684 | | return 0; |
| 685 | | } |
| 686 | | |
| 687 | | int main(int argc, char **argv) { |
| 688 | | ... |
| 689 | | |
| 690 | | // txen is a string: DTR, RTS, or gpio<n> |
| 691 | | if (txen && (0 == strncasecmp(txen, "gpio", 4))) |
| 692 | | { |
| 693 | | char str[64]; |
| 694 | | int gpio = atoi(txen + 4); |
| 695 | | |
| 696 | | printf("exporting gpio%d\n", gpio); |
| 697 | | sprintf(str, "%d", gpio); |
| 698 | | write_file(str, "/sys/class/gpio/export"); |
| 699 | | sprintf(str, "/sys/class/gpio/gpio%d/direction", gpio); |
| 700 | | write_file("out", str); |
| 701 | | sprintf(str, "/sys/class/gpio/gpio%d/value", gpio); |
| 702 | | write_file("0", str); // assuming TXEN active-high |
| 703 | | } |
| 704 | | |
| 705 | | // transmit data |
| 706 | | assert_tx(fd, txen, 1); // assert TXEN |
| 707 | | write(fd, buf, sz); // transmit data |
| 708 | | tcdrain(fd); //wait for all characters to be transmitted |
| 709 | | assert_tx(fd, txen, 0); // de-assert TXEN |
| 710 | | |
| 711 | | // receive data |
| 712 | | ... |
| 713 | | }}} |
| 714 | | |
| 812 | | |
| 813 | | |
| 814 | | [=#laguna] |
| 815 | | === Laguna: GW2382 |
| 816 | | J8 is an expansion header and is by default mapped to /dev/ttyS2. J2 and J4 are connected to /dev/ttyS0. The GPS is hooked to /dev/ttyS1. |
| 817 | | |
| 818 | | === Laguna: Baud Rate |
| 819 | | The Laguna Family has the option of 2 clocks for the serial port, 24MHz and 14.7456MHz. |
| 820 | | |
| 821 | | By default the 24MHz clock is loaded. This clock creates drift for some baud rates as seen below. |
| 822 | | |
| 823 | | Because this drift is consistent on Laguna boards, Laguna to Laguna serial will work at all baud rates. |
| 824 | | |
| 825 | | Therefore, we suggest using rates below 115200. Please contact support at Gateworks if higher baud rates are required. |
| 826 | | |
| 827 | | Laguna Buadrates with default 24MHz clock: |
| 828 | | ||= Target baudrate =||= 24MHz ref div =||= actual baudrate =||= % error =|| |
| 829 | | || 4800 || 312.50 || 4792 || 0.17 || |
| 830 | | || 9600 || 156.25 || 9615 || -0.16 || |
| 831 | | || 19200 || 78.13 || 19231 || -0.16 || |
| 832 | | || 38400 || 39.06 || 38462 || -0.16 || |
| 833 | | || 57600 || 26.04 || 57692 || -0.16 || |
| 834 | | || 115200 || 13.02 || 115385 || -0.16 || |
| 835 | | || 230400 || 6.51 || 214286 || 6.99 || |
| 836 | | || 460800 || 3.26 || 500000 || -8.51 || |
| 837 | | || 921600 || 1.63 || 750000 || 18.62 || |
| 838 | | || 1500000 || 1.00 || 1500000 || 0 || |
