main.c

   1 /*
   2  * Copyright (c) 2011, Olivier MATZ <zer0@droids-corp.org>
   3  * All rights reserved.
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are met:
   6  *
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of the University of California, Berkeley nor the
  13  *       names of its contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 /* fuses:
  29  * avrdude -p atmega1284p -P usb -c avrispmkii -U lfuse:w:0xff:m -U hfuse:w:0x99:m -U efuse:w:0xff:m
  30  */
  31
  32 #include <aversive.h>
  33 #include <aversive/queue.h>
  34 #include <aversive/endian.h>
  35 #include <aversive/wait.h>
  36 #include <aversive/error.h>
  37
  38 #include <uart.h>
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <stdint.h>
  43 #include <inttypes.h>
  44 #include <stdlib.h>
  45 #include <stdarg.h>
  46 #include <errno.h>
  47 #include <ctype.h>
  48
  49 #include <scheduler.h>
  50 #include <clock_time.h>
  51 #include <parse.h>
  52 #include <rdline.h>
  53 #include <timer.h>
  54
  55 #include "main.h"
  56
  57 struct xbeeboard xbeeboard;
  58 volatile uint16_t global_ms;
  59 struct callout_manager cm;
  60
  61 #define TIMEOUT_MS 1000
  62
  63 /* global xbee device */
  64 struct xbee_dev *xbee_dev;
  65
  66 /* events */
  67 //static struct event stdin_read_event, xbee_read_event;
  68
  69 /* parameters */
  70 int xbee_raw = 0;
  71 int xbee_hexdump = 0;
  72 int xbee_debug = 0;
  73
  74 int xbee_cmdline_input_enabled = 1;
  75
  76 static struct xbee_ctx xbee_ctx[XBEE_MAX_CHANNEL];
  77
  78 static void hexdump(const char *title, const void *buf, unsigned int len)
  79 {
  80         unsigned int i, out, ofs;
  81         const unsigned char *data = buf;
  82 #define LINE_LEN 80
  83         char line[LINE_LEN];    /* space needed 8+16*3+3+16 == 75 */
  84
  85         printf_P(PSTR("%s at [%p], len=%d\r\n"), title, data, len);
  86         ofs = 0;
  87         while (ofs < len) {
  88                 /* format 1 line in the buffer, then use printk to print them */
  89                 out = snprintf_P(line, LINE_LEN, PSTR("%08X"), ofs);
  90                 for (i=0; ofs+i < len && i<16; i++)
  91                         out += snprintf_P(line+out, LINE_LEN - out,
  92                                           PSTR(" %02X"),
  93                                           data[ofs+i]&0xff);
  94                 for (;i<=16;i++)
  95                         out += snprintf(line+out, LINE_LEN - out, "   ");
  96                 for (i=0; ofs < len && i<16; i++, ofs++) {
  97                         unsigned char c = data[ofs];
  98                         if (!isascii(c) || !isprint(c))
  99                                 c = '.';
 100                         out += snprintf_P(line+out,
 101                                           LINE_LEN - out,
 102                                           PSTR("%c"), c);
 103                 }
 104                 printf_P(PSTR("%s\r\n"), line);
 105         }
 106 }
 107
 108 static int parse_xmit_status(struct xbee_ctx *ctx,
 109                              struct xbee_xmit_status_hdr *frame, unsigned len)
 110 {
 111         (void)len;
 112
 113         if (ctx == NULL) {
 114                 printf_P(PSTR("no context\r\n"));
 115                 return -1;
 116         }
 117
 118         /* see if it matches a xmit query (atcmd_query must be NULL) */
 119         if (ctx->atcmd_query[0] != '\0') {
 120                 printf_P(PSTR("invalid response 2\r\n"));
 121                 return -1;
 122         }
 123
 124         /* XXX use defines for these values */
 125         if (frame->delivery_status == 0x00)
 126                 printf_P(PSTR("Success\r\n"));
 127         else if (frame->delivery_status == 0x01)
 128                 printf_P(PSTR("MAC ACK Failure\r\n"));
 129         else if (frame->delivery_status == 0x15)
 130                 printf_P(PSTR("Invalid destination endpoint\r\n"));
 131         else if (frame->delivery_status == 0x21)
 132                 printf_P(PSTR("Network ACK Failure\r\n"));
 133         else if (frame->delivery_status == 0x25)
 134                 printf_P(PSTR("Route Not Found\r\n"));
 135
 136         return 0;
 137 }
 138
 139 static int dump_atcmd(struct xbee_ctx *ctx, struct xbee_atresp_hdr *frame,
 140                unsigned len)
 141 {
 142         char atcmd_str[3];
 143         const struct xbee_atcmd *cmd_pgm;
 144         struct xbee_atcmd cmd;
 145         union {
 146                 uint8_t u8;
 147                 uint16_t u16;
 148                 uint32_t u32;
 149                 int16_t s16;
 150         } __attribute__((packed)) *result;
 151
 152         if (ctx == NULL) {
 153                 printf_P(PSTR("no context\r\n"));
 154                 return -1;
 155         }
 156
 157         /* get AT command from frame */
 158         memcpy(atcmd_str, &frame->cmd, 2);
 159         atcmd_str[2] = '\0';
 160
 161         /* see if it matches query */
 162         if (memcmp(atcmd_str, ctx->atcmd_query, 2)) {
 163                 printf_P(PSTR("invalid response <%c%c><%s><%s>\r\n"),
 164                          frame->cmd & 0xFF,
 165                          (frame->cmd >> 8) & 0xFF,
 166                          atcmd_str, ctx->atcmd_query);
 167                 return -1;
 168         }
 169
 170         /* see if it exists */
 171         cmd_pgm = xbee_atcmd_lookup_name(atcmd_str);
 172         if (cmd_pgm == NULL) {
 173                 printf_P(PSTR("unknown response\r\n"));
 174                 return -1;
 175         }
 176         memcpy_P(&cmd, cmd_pgm, sizeof(cmd));
 177
 178         /* bad status */
 179         if (frame->status == 1) {
 180                 printf_P(PSTR("Status is error\r\n"));
 181                 return -1;
 182         }
 183         else if (frame->status == 2) {
 184                 printf_P(PSTR("Invalid command\r\n"));
 185                 return -1;
 186         }
 187         else if (frame->status == 3) {
 188                 printf_P(PSTR("Invalid parameter\r\n"));
 189                 return -1;
 190         }
 191         else if (frame->status != 0) {
 192                 printf_P(PSTR("Unknown status error %d\r\n"), frame->status);
 193                 return -1;
 194         }
 195
 196         /* callback */
 197         if (ctx->func != NULL)
 198                 ctx->func(frame, len, ctx->arg);
 199
 200         /* dump frame */
 201         result = (void *)frame->data;
 202         len -= offsetof(struct xbee_atresp_hdr, data);
 203         if (cmd.flags & XBEE_ATCMD_F_PARAM_U8 && len == sizeof(uint8_t))
 204                 printf_P(PSTR("<%s> is 0x%x\r\n"), atcmd_str, result->u8);
 205         else if (cmd.flags & XBEE_ATCMD_F_PARAM_U16 && len == sizeof(uint16_t))
 206                 printf_P(PSTR("<%s> is 0x%x\r\n"),
 207                          atcmd_str,
 208                          ntohs(result->u16));
 209         else if (cmd.flags & XBEE_ATCMD_F_PARAM_U32 && len == sizeof(uint32_t))
 210                 printf_P(PSTR("<%s> is 0x%"PRIx32"\r\n"),
 211                          atcmd_str,
 212                          ntohl(result->u32));
 213         else if (cmd.flags & XBEE_ATCMD_F_PARAM_S16 && len == sizeof(int16_t))
 214                 printf_P(PSTR("<%s> is %d\r\n"), atcmd_str, ntohs(result->s16));
 215         else if (len == 0)
 216                 printf_P(PSTR("no data, status ok\r\n"));
 217         else
 218                 hexdump("atcmd answer", frame->data, len);
 219
 220
 221         return 0;
 222 }
 223
 224
 225 int xbee_recv_data(struct xbee_recv_hdr *recvframe, unsigned len)
 226 {
 227         unsigned int datalen;
 228         struct rc_proto_hdr *rch = (struct rc_proto_hdr *) &recvframe->data;
 229
 230         if (len <  sizeof(*recvframe))
 231                 return -1;
 232
 233         datalen = len - sizeof(*recvframe);
 234         if (datalen < sizeof(struct rc_proto_hdr))
 235                 return -1;
 236
 237         switch (rch->type) {
 238                 case RC_PROTO_TYPE_CHANNEL: {
 239                         struct rc_proto_channel *rcc =
 240                                 (struct rc_proto_channel *) recvframe->data;
 241                         int16_t val;
 242                         if (datalen != sizeof(struct rc_proto_channel))
 243                                 return -1;
 244                         val = ntohs(rcc->axis[0]);
 245                         val >>= 6;
 246                         val += 512;
 247                         spi_servo_set(0, val);
 248                         break;
 249                                   }
 250                 case RC_PROTO_TYPE_RANGE: {
 251                         struct rc_proto_range *rcr =
 252                                 (struct rc_proto_range *) recvframe->data;
 253
 254                         if (datalen != sizeof(struct rc_proto_range))
 255                                 return -1;
 256
 257                         if (rcr->power_level >= MAX_POWER_LEVEL)
 258                                 return -1;
 259
 260                         rc_proto_rx_range(rcr->power_level);
 261
 262                         break;
 263                 }
 264                 default:
 265                         return -1;
 266         }
 267
 268         return 0;
 269 }
 270
 271 /* socat /dev/ttyUSB0,raw,echo=0,b115200 /dev/ttyACM1,raw,echo=0,b115200 */
 272 void xbee_rx(struct xbee_dev *dev, int channel, int type,
 273              void *frame, unsigned len, void *opaque)
 274 {
 275         struct xbee_ctx *ctx = opaque;
 276         int do_hexdump = xbee_hexdump;
 277
 278         if (xbee_debug)
 279                 printf_P(PSTR("type=0x%x, channel=%d, ctx=%p\r\n"),
 280                          type, channel, ctx);
 281
 282         /* if ctx is !NULL, it is an answer to a query */
 283         if (ctx != NULL) {
 284                 /* XXX only delete timeout if answer matched */
 285                 xbee_unload_timeout(ctx);
 286                 if (xbee_debug && ctx->atcmd_query)
 287                         printf_P(PSTR("Received answer to query <%c%c>\r\n"),
 288                                  ctx->atcmd_query[0], ctx->atcmd_query[1]);
 289         }
 290
 291         /* some additional checks before sending */
 292         switch (type) {
 293                 case XBEE_TYPE_MODEM_STATUS: {
 294                         printf_P(PSTR("Received Modem Status frame\r\n"));
 295                         break;
 296                 }
 297
 298                 case XBEE_TYPE_RMT_ATRESP: {
 299                         union {
 300                                 uint64_t u64;
 301                                 struct {
 302 #if BYTE_ORDER == LITTLE_ENDIAN
 303                                         uint32_t low;
 304                                         uint32_t high;
 305 #else
 306                                         uint32_t high;
 307                                         uint32_t low;
 308 #endif
 309                                 } u32;
 310                         } addr;
 311                         memcpy(&addr, frame, sizeof(addr));
 312                         addr.u64 = ntohll(addr.u64);
 313                         printf_P(PSTR("from remote address %"PRIx32"%"PRIx32"\r\n"),
 314                                  addr.u32.high, addr.u32.low);
 315
 316                         /* this answer contains an atcmd answer at offset 10 */
 317                         if (dump_atcmd(ctx, frame + 10, len - 10) < 0)
 318                                 do_hexdump = 1;
 319                         break;
 320                 }
 321                 case XBEE_TYPE_ATRESP: {
 322                         if (dump_atcmd(ctx, frame, len) < 0)
 323                                 do_hexdump = 1;
 324                         break;
 325                 }
 326
 327                 case XBEE_TYPE_XMIT_STATUS: {
 328                         if (parse_xmit_status(ctx, frame, len) < 0)
 329                                 do_hexdump = 1;
 330                         break;
 331                 }
 332
 333                 case XBEE_TYPE_RECV: {
 334                         if (xbee_recv_data(frame, len) < 0)
 335                                 do_hexdump = 1;
 336                         break;
 337                 }
 338
 339                 case XBEE_TYPE_ATCMD:
 340                 case XBEE_TYPE_ATCMD_Q:
 341                 case XBEE_TYPE_XMIT:
 342                 case XBEE_TYPE_EXPL_XMIT:
 343                 case XBEE_TYPE_RMT_ATCMD:
 344                 case XBEE_TYPE_EXPL_RECV:
 345                 case XBEE_TYPE_NODE_ID:
 346                 default:
 347                         printf_P(PSTR("Invalid frame\r\n"));
 348                         do_hexdump = 1;
 349                         break;
 350         }
 351
 352         if (do_hexdump)
 353                 hexdump("undecoded rx frame", frame, len);
 354
 355         /* restart command line if it was a blocking query */
 356         if (ctx != NULL) {
 357                 xbee_unregister_channel(dev, channel);
 358                 if (ctx->foreground) {
 359                         xbee_stdin_enable();
 360                         rdline_newline(&xbeeboard.rdl, xbeeboard.prompt);
 361                 }
 362         }
 363 }
 364
 365 static int xbeeapp_send(struct xbee_ctx *ctx, int type, void *buf, unsigned len,
 366                         int foreground)
 367 {
 368         int ret;
 369         int channel;
 370
 371         if (len > XBEE_MAX_FRAME_LEN) {
 372                 printf_P(PSTR("frame too large\r\n"));
 373                 return -1;
 374         }
 375
 376         /* register a channel */
 377         channel = xbee_register_channel(xbee_dev, XBEE_CHANNEL_ANY,
 378                                         xbee_rx, NULL);
 379         if (channel < 0) {
 380                 printf_P(PSTR("cannot send: no free channel\r\n"));
 381                 return -1;
 382         }
 383
 384         /* copy context in the static struct table (avoiding a malloc) */
 385         memcpy(&xbee_ctx[channel], ctx, sizeof(*ctx));
 386         ctx = &xbee_ctx[channel];
 387         xbee_set_opaque(xbee_dev, channel, ctx);
 388
 389         if (xbee_debug)
 390                 printf_P(PSTR("send frame channel=%d type=0x%x len=%d\r\n"),
 391                          channel, type, len);
 392         if (xbee_hexdump)
 393                 hexdump("xmit frame", buf, len);
 394
 395         /* transmit the frame on this channel */
 396         ret = xbee_proto_xmit(xbee_dev, channel, type, buf,
 397                               len);
 398         if (ret < 0) {
 399                 printf_P(PSTR("cannot send\r\n"));
 400                 xbee_unregister_channel(xbee_dev, channel);
 401                 return -1;
 402         }
 403
 404         ctx->channel = channel;
 405         xbee_load_timeout(ctx);   /* load a timeout event */
 406
 407         /* suspend command line until we have answer or timeout */
 408         if (foreground) {
 409                 ctx->foreground = 1;
 410                 rdline_stop(&xbeeboard.rdl); /* don't display prompt when return */
 411                 xbee_stdin_disable();  /* unload file descriptor polling */
 412         }
 413
 414         return 0;
 415 }
 416
 417 /* send an AT command with parameters filled by caller. Disable
 418  * command line until we get the answer or until a timeout occurs */
 419 int xbeeapp_send_atcmd(const char *atcmd_str,
 420                        void *param, unsigned param_len, int foreground,
 421                        int (*func)(void *frame, unsigned len, void *arg), void *arg)
 422 {
 423         struct xbee_ctx ctx;
 424         struct {
 425                 struct xbee_atcmd_hdr atcmd;
 426                 char buf[XBEE_MAX_FRAME_LEN];
 427         } __attribute__((packed)) frame;
 428
 429         memset(&ctx, 0, sizeof(ctx));
 430         ctx.atcmd_query[0] = atcmd_str[0];
 431         ctx.atcmd_query[1] = atcmd_str[1];
 432         ctx.func = func;
 433         ctx.arg = arg;
 434
 435         memcpy(&frame.atcmd.cmd, atcmd_str, 2);
 436         memcpy(&frame.buf, param, param_len);
 437
 438         if (xbeeapp_send(&ctx, XBEE_TYPE_ATCMD, &frame,
 439                          sizeof(struct xbee_atcmd_hdr) +
 440                          param_len, foreground) < 0) {
 441                 return -1;
 442         }
 443
 444         return 0;
 445 }
 446
 447 int xbeeapp_send_msg(uint64_t addr, void *data,
 448                      unsigned data_len, int foreground)
 449 {
 450         struct xbee_ctx ctx;
 451         struct {
 452                 struct xbee_xmit_hdr xmit;
 453                 char buf[XBEE_MAX_FRAME_LEN];
 454         } __attribute__((packed)) frame;
 455
 456         memset(&ctx, 0, sizeof(ctx));
 457         ctx.atcmd_query[0] = '\0';
 458
 459         frame.xmit.dstaddr = htonll(addr);
 460         frame.xmit.reserved = htons(0xFFFE);
 461         frame.xmit.bcast_radius = 0;
 462         frame.xmit.opts = 0;
 463         memcpy(&frame.buf, data, data_len);
 464
 465         if (xbeeapp_send(&ctx, XBEE_TYPE_XMIT, &frame,
 466                          sizeof(struct xbee_xmit_hdr) +
 467                          data_len, foreground) < 0) {
 468                 return -1;
 469         }
 470
 471         return 0;
 472 }
 473
 474 void xbee_stdin_enable(void)
 475 {
 476         xbee_cmdline_input_enabled = 1;
 477 }
 478
 479 void xbee_stdin_disable(void)
 480 {
 481         xbee_cmdline_input_enabled = 0;
 482 }
 483
 484 static void evt_timeout(struct callout_manager *cm, struct callout *clt,
 485                         void *arg)
 486 {
 487         struct xbee_ctx *ctx = arg;
 488
 489         (void)cm;
 490         (void)clt;
 491
 492         printf_P(PSTR("Timeout\r\n"));
 493
 494         /* restart command line */
 495         xbee_stdin_enable();
 496         rdline_newline(&xbeeboard.rdl, xbeeboard.prompt);
 497
 498         /* free event */
 499         xbee_unregister_channel(xbee_dev, ctx->channel);
 500 }
 501
 502 void xbee_load_timeout(struct xbee_ctx *ctx)
 503 {
 504         callout_reset(&cm, &ctx->timeout, TIMEOUT_MS, SINGLE, evt_timeout, ctx);
 505 }
 506
 507 void xbee_unload_timeout(struct xbee_ctx *ctx)
 508 {
 509         callout_stop(&cm, &ctx->timeout);
 510 }
 511
 512 void bootloader(void)
 513 {
 514 #define BOOTLOADER_ADDR 0x3f000
 515         if (pgm_read_byte_far(BOOTLOADER_ADDR) == 0xff) {
 516                 printf_P(PSTR("Bootloader is not present\r\n"));
 517                 return;
 518         }
 519         cli();
 520         /* ... very specific :( */
 521         TIMSK0 = 0;
 522         TIMSK1 = 0;
 523         TIMSK2 = 0;
 524         TIMSK3 = 0;
 525         EIMSK = 0;
 526         UCSR0B = 0;
 527         UCSR1B = 0;
 528         SPCR = 0;
 529         TWCR = 0;
 530         ACSR = 0;
 531         ADCSRA = 0;
 532
 533         /* XXX */
 534         /* __asm__ __volatile__ ("ldi r31,0xf8\n"); */
 535         /* __asm__ __volatile__ ("ldi r30,0x00\n"); */
 536         /* __asm__ __volatile__ ("eijmp\n"); */
 537 }
 538
 539 void xbee_mainloop(void)
 540 {
 541         while (1) {
 542                 callout_manage(&cm);
 543
 544                 if (xbee_raw) {
 545                         int16_t c;
 546
 547                         /* from xbee to cmdline */
 548                         c = xbee_dev_recv(NULL);
 549                         if (c >= 0)
 550                                 cmdline_dev_send((uint8_t)c, NULL);
 551
 552                         /* from cmdline to xbee */
 553                         c = cmdline_dev_recv(NULL);
 554                         if (c == 4) { /* CTRL-d */
 555                                 xbee_raw = 0;
 556                                 rdline_newline(&xbeeboard.rdl,
 557                                                xbeeboard.prompt);
 558                         }
 559                         else if (c >= 0) {
 560                                 /* send to xbee */
 561                                 xbee_dev_send((uint8_t)c, NULL);
 562
 563                                 /* echo on cmdline */
 564                                 cmdline_dev_send((uint8_t)c, NULL);
 565                         }
 566                 }
 567                 else {
 568                         if (xbee_cmdline_input_enabled)
 569                                 cmdline_poll();
 570                         xbee_proto_rx(xbee_dev);
 571                 }
 572         }
 573 }
 574
 575 /* return time in milliseconds on unsigned 16 bits */
 576 static uint16_t get_time_ms(void)
 577 {
 578         return global_ms;
 579 }
 580
 581 static void main_timer_interrupt(void)
 582 {
 583         static uint16_t cycles;
 584         static uint8_t cpt;
 585
 586         /* interrupt every 2048 cycles */
 587         cycles += 2048;
 588         if (cycles >= 12000) {
 589                 cycles -= 12000;
 590                 global_ms ++;
 591         }
 592
 593         /* LED blink */
 594         if (global_ms & 0x80)
 595                 LED1_ON();
 596         else
 597                 LED1_OFF();
 598
 599         /* call scheduler every 682us with interrupt unlocked */
 600         sei();
 601         if ((cpt & 0x3) == 0)
 602                 scheduler_interrupt();
 603 }
 604
 605 int main(void)
 606 {
 607         //struct callout t1;
 608         FILE *xbee_file;
 609         int8_t err;
 610         struct xbee_dev dev;
 611
 612         DDRA = 0x07; /* LEDs */
 613
 614         uart_init();
 615         uart_register_rx_event(CMDLINE_UART, emergency);
 616
 617         fdevopen(cmdline_dev_send, cmdline_dev_recv);
 618         xbee_file = fdevopen(xbee_dev_send, xbee_dev_recv);
 619         scheduler_init();
 620         timer_init();
 621         timer0_register_OV_intr(main_timer_interrupt);
 622
 623         cmdline_init();
 624         spi_servo_init();
 625
 626         printf_P(PSTR("\r\n"));
 627         rdline_newline(&xbeeboard.rdl, xbeeboard.prompt);
 628
 629         callout_manager_init(&cm, get_time_ms);
 630         //callout_reset(&cm, &t1, 500, PERIODICAL, do_led_blink, NULL);
 631
 632         /* initialize libxbee */
 633         err = xbee_init();
 634         if (err < 0)
 635                 return -1;
 636
 637         xbee_dev = &dev;
 638
 639         /* open xbee device */
 640         if (xbee_open(xbee_dev, xbee_file) < 0)
 641                 return -1;
 642
 643         /* register default channel with a callback */
 644         if (xbee_register_channel(xbee_dev, XBEE_DEFAULT_CHANNEL,
 645                                   xbee_rx, NULL) < 0) {
 646                 fprintf(stderr, "cannot register default channel\n");
 647                 return -1;
 648         }
 649
 650         sei();
 651
 652         xbee_mainloop();
 653         return 0;
 654 }