tool/mbed/mbed-sdk/libraries/tests/peripherals/AX12/AX12.cpp

   1 /* mbed AX-12+ Servo Library
   2  *
   3  * Copyright (c) 2010, cstyles (http://mbed.org)
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21  * THE SOFTWARE.
  22  */
  23
  24 #include "AX12.h"
  25 #include "mbed.h"
  26
  27 AX12::AX12(PinName tx, PinName rx, int ID, int baud)
  28         : _ax12(tx,rx) {
  29     _baud = baud;
  30     _ID = ID;
  31     _ax12.baud(_baud);
  32
  33 }
  34
  35 // Set the mode of the servo
  36 //  0 = Positional (0-300 degrees)
  37 //  1 = Rotational -1 to 1 speed
  38 int AX12::SetMode(int mode) {
  39
  40     if (mode == 1) { // set CR
  41         SetCWLimit(0);
  42         SetCCWLimit(0);
  43         SetCRSpeed(0.0);
  44     } else {
  45         SetCWLimit(0);
  46         SetCCWLimit(300);
  47         SetCRSpeed(0.0);
  48     }
  49     return(0);
  50 }
  51
  52
  53 // if flag[0] is set, were blocking
  54 // if flag[1] is set, we're registering
  55 // they are mutually exclusive operations
  56 int AX12::SetGoal(int degrees, int flags) {
  57
  58     char reg_flag = 0;
  59     char data[2];
  60
  61     // set the flag is only the register bit is set in the flag
  62     if (flags == 0x2) {
  63         reg_flag = 1;
  64     }
  65
  66     // 1023 / 300 * degrees
  67     short goal = (1023 * degrees) / 300;
  68 #ifdef AX12_DEBUG
  69     printf("SetGoal to 0x%x\n",goal);
  70 #endif
  71
  72     data[0] = goal & 0xff; // bottom 8 bits
  73     data[1] = goal >> 8;   // top 8 bits
  74
  75     // write the packet, return the error code
  76     int rVal = write(_ID, AX12_REG_GOAL_POSITION, 2, data, reg_flag);
  77
  78     if (flags == 1) {
  79         // block until it comes to a halt
  80         while (isMoving()) {}
  81     }
  82     return(rVal);
  83 }
  84
  85
  86 // Set continuous rotation speed from -1 to 1
  87 int AX12::SetCRSpeed(float speed) {
  88
  89     // bit 10     = direction, 0 = CCW, 1=CW
  90     // bits 9-0   = Speed
  91     char data[2];
  92
  93     int goal = (0x3ff * abs(speed));
  94
  95     // Set direction CW if we have a negative speed
  96     if (speed < 0) {
  97         goal |= (0x1 << 10);
  98     }
  99
 100     data[0] = goal & 0xff; // bottom 8 bits
 101     data[1] = goal >> 8;   // top 8 bits
 102
 103     // write the packet, return the error code
 104     int rVal = write(_ID, 0x20, 2, data);
 105
 106     return(rVal);
 107 }
 108
 109
 110 int AX12::SetCWLimit (int degrees) {
 111
 112     char data[2];
 113
 114     // 1023 / 300 * degrees
 115     short limit = (1023 * degrees) / 300;
 116
 117 #ifdef AX12_DEBUG
 118     printf("SetCWLimit to 0x%x\n",limit);
 119 #endif
 120
 121     data[0] = limit & 0xff; // bottom 8 bits
 122     data[1] = limit >> 8;   // top 8 bits
 123
 124     // write the packet, return the error code
 125     return (write(_ID, AX12_REG_CW_LIMIT, 2, data));
 126
 127 }
 128
 129 int AX12::SetCCWLimit (int degrees) {
 130
 131     char data[2];
 132
 133     // 1023 / 300 * degrees
 134     short limit = (1023 * degrees) / 300;
 135
 136 #ifdef AX12_DEBUG
 137     printf("SetCCWLimit to 0x%x\n",limit);
 138 #endif
 139
 140     data[0] = limit & 0xff; // bottom 8 bits
 141     data[1] = limit >> 8;   // top 8 bits
 142
 143     // write the packet, return the error code
 144     return (write(_ID, AX12_REG_CCW_LIMIT, 2, data));
 145 }
 146
 147
 148 int AX12::SetID (int CurrentID, int NewID) {
 149
 150     char data[1];
 151     data[0] = NewID;
 152
 153 #ifdef AX12_DEBUG
 154     printf("Setting ID from 0x%x to 0x%x\n",CurrentID,NewID);
 155 #endif
 156
 157     return (write(CurrentID, AX12_REG_ID, 1, data));
 158
 159 }
 160
 161
 162 int AX12::SetBaud (int baud) {
 163
 164     char data[1];
 165     data[0] = baud;
 166
 167 #ifdef AX12_DEBUG
 168     printf("Setting Baud rate to %d\n",baud);
 169 #endif
 170
 171     return (write(0xFE, AX12_REG_BAUD, 1, data));
 172
 173 }
 174
 175
 176
 177 // return 1 is the servo is still in flight
 178 int AX12::isMoving(void) {
 179
 180     char data[1];
 181     read(_ID,AX12_REG_MOVING,1,data);
 182     return(data[0]);
 183 }
 184
 185
 186 void AX12::trigger(void) {
 187
 188     char TxBuf[16];
 189     char sum = 0;
 190
 191 #ifdef AX12_TRIGGER_DEBUG
 192     // Build the TxPacket first in RAM, then we'll send in one go
 193     printf("\nTriggered\n");
 194     printf("\nTrigger Packet\n  Header : 0xFF, 0xFF\n");
 195 #endif
 196
 197     TxBuf[0] = 0xFF;
 198     TxBuf[1] = 0xFF;
 199
 200     // ID - Broadcast
 201     TxBuf[2] = 0xFE;
 202     sum += TxBuf[2];
 203
 204 #ifdef AX12_TRIGGER_DEBUG
 205     printf("  ID : %d\n",TxBuf[2]);
 206 #endif
 207
 208     // Length
 209     TxBuf[3] = 0x02;
 210     sum += TxBuf[3];
 211
 212 #ifdef AX12_TRIGGER_DEBUG
 213     printf("  Length %d\n",TxBuf[3]);
 214 #endif
 215
 216     // Instruction - ACTION
 217     TxBuf[4] = 0x04;
 218     sum += TxBuf[4];
 219
 220 #ifdef AX12_TRIGGER_DEBUG
 221     printf("  Instruction 0x%X\n",TxBuf[5]);
 222 #endif
 223
 224     // Checksum
 225     TxBuf[5] = 0xFF - sum;
 226 #ifdef AX12_TRIGGER_DEBUG
 227     printf("  Checksum 0x%X\n",TxBuf[5]);
 228 #endif
 229
 230     // Transmit the packet in one burst with no pausing
 231     for (int i = 0; i < 6 ; i++) {
 232         _ax12.putc(TxBuf[i]);
 233     }
 234
 235     // This is a broadcast packet, so there will be no reply
 236     return;
 237 }
 238
 239
 240 float AX12::GetPosition(void) {
 241
 242 #ifdef AX12_DEBUG
 243     printf("\nGetPosition(%d)",_ID);
 244 #endif
 245
 246     char data[2];
 247
 248     int ErrorCode = read(_ID, AX12_REG_POSITION, 2, data);
 249     short position = data[0] + (data[1] << 8);
 250     float angle = (position * 300)/1024;
 251
 252     return (angle);
 253 }
 254
 255
 256 float AX12::GetTemp (void) {
 257
 258 #ifdef AX12_DEBUG
 259     printf("\nGetTemp(%d)",_ID);
 260 #endif
 261
 262     char data[1];
 263     int ErrorCode = read(_ID, AX12_REG_TEMP, 1, data);
 264     float temp = data[0];
 265     return(temp);
 266 }
 267
 268
 269 float AX12::GetVolts (void) {
 270
 271 #ifdef AX12_DEBUG
 272     printf("\nGetVolts(%d)",_ID);
 273 #endif
 274
 275     char data[1];
 276     int ErrorCode = read(_ID, AX12_REG_VOLTS, 1, data);
 277     float volts = data[0]/10.0;
 278     return(volts);
 279 }
 280
 281
 282 int AX12::read(int ID, int start, int bytes, char* data) {
 283
 284     char PacketLength = 0x4;
 285     char TxBuf[16];
 286     char sum = 0;
 287     char Status[16];
 288
 289     Status[4] = 0xFE; // return code
 290
 291 #ifdef AX12_READ_DEBUG
 292     printf("\nread(%d,0x%x,%d,data)\n",ID,start,bytes);
 293 #endif
 294
 295     // Build the TxPacket first in RAM, then we'll send in one go
 296 #ifdef AX12_READ_DEBUG
 297     printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
 298 #endif
 299
 300     TxBuf[0] = 0xff;
 301     TxBuf[1] = 0xff;
 302
 303     // ID
 304     TxBuf[2] = ID;
 305     sum += TxBuf[2];
 306
 307 #ifdef AX12_READ_DEBUG
 308     printf("  ID : %d\n",TxBuf[2]);
 309 #endif
 310
 311     // Packet Length
 312     TxBuf[3] = PacketLength;    // Length = 4 ; 2 + 1 (start) = 1 (bytes)
 313     sum += TxBuf[3];            // Accululate the packet sum
 314
 315 #ifdef AX12_READ_DEBUG
 316     printf("  Length : 0x%x\n",TxBuf[3]);
 317 #endif
 318
 319     // Instruction - Read
 320     TxBuf[4] = 0x2;
 321     sum += TxBuf[4];
 322
 323 #ifdef AX12_READ_DEBUG
 324     printf("  Instruction : 0x%x\n",TxBuf[4]);
 325 #endif
 326
 327     // Start Address
 328     TxBuf[5] = start;
 329     sum += TxBuf[5];
 330
 331 #ifdef AX12_READ_DEBUG
 332     printf("  Start Address : 0x%x\n",TxBuf[5]);
 333 #endif
 334
 335     // Bytes to read
 336     TxBuf[6] = bytes;
 337     sum += TxBuf[6];
 338
 339 #ifdef AX12_READ_DEBUG
 340     printf("  No bytes : 0x%x\n",TxBuf[6]);
 341 #endif
 342
 343     // Checksum
 344     TxBuf[7] = 0xFF - sum;
 345 #ifdef AX12_READ_DEBUG
 346     printf("  Checksum : 0x%x\n",TxBuf[7]);
 347 #endif
 348
 349     // Transmit the packet in one burst with no pausing
 350     for (int i = 0; i<8 ; i++) {
 351         _ax12.putc(TxBuf[i]);
 352     }
 353
 354     // Wait for the bytes to be transmitted
 355     wait (0.00002);
 356
 357     // Skip if the read was to the broadcast address
 358     if (_ID != 0xFE) {
 359
 360
 361
 362         // response packet is always 6 + bytes
 363         // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
 364         // timeout is a little more than the time to transmit
 365         // the packet back, i.e. (6+bytes)*10 bit periods
 366
 367         int timeout = 0;
 368         int plen = 0;
 369         while ((timeout < ((6+bytes)*10)) && (plen<(6+bytes))) {
 370
 371             if (_ax12.readable()) {
 372                 Status[plen] = _ax12.getc();
 373                 plen++;
 374                 timeout = 0;
 375             }
 376
 377             // wait for the bit period
 378             wait (1.0/_baud);
 379             timeout++;
 380         }
 381
 382         if (timeout == ((6+bytes)*10) ) {
 383             return(-1);
 384         }
 385
 386         // Copy the data from Status into data for return
 387         for (int i=0; i < Status[3]-2 ; i++) {
 388             data[i] = Status[5+i];
 389         }
 390
 391 #ifdef AX12_READ_DEBUG
 392         printf("\nStatus Packet\n");
 393         printf("  Header : 0x%x\n",Status[0]);
 394         printf("  Header : 0x%x\n",Status[1]);
 395         printf("  ID : 0x%x\n",Status[2]);
 396         printf("  Length : 0x%x\n",Status[3]);
 397         printf("  Error Code : 0x%x\n",Status[4]);
 398
 399         for (int i=0; i < Status[3]-2 ; i++) {
 400             printf("  Data : 0x%x\n",Status[5+i]);
 401         }
 402
 403         printf("  Checksum : 0x%x\n",Status[5+(Status[3]-2)]);
 404 #endif
 405
 406     } // if (ID!=0xFE)
 407
 408     return(Status[4]);
 409 }
 410
 411
 412 int AX12::write(int ID, int start, int bytes, char* data, int flag) {
 413 // 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum
 414
 415     char TxBuf[16];
 416     char sum = 0;
 417     char Status[6];
 418
 419 #ifdef AX12_WRITE_DEBUG
 420     printf("\nwrite(%d,0x%x,%d,data,%d)\n",ID,start,bytes,flag);
 421 #endif
 422
 423     // Build the TxPacket first in RAM, then we'll send in one go
 424 #ifdef AX12_WRITE_DEBUG
 425     printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
 426 #endif
 427
 428     TxBuf[0] = 0xff;
 429     TxBuf[1] = 0xff;
 430
 431     // ID
 432     TxBuf[2] = ID;
 433     sum += TxBuf[2];
 434
 435 #ifdef AX12_WRITE_DEBUG
 436     printf("  ID : %d\n",TxBuf[2]);
 437 #endif
 438
 439     // packet Length
 440     TxBuf[3] = 3+bytes;
 441     sum += TxBuf[3];
 442
 443 #ifdef AX12_WRITE_DEBUG
 444     printf("  Length : %d\n",TxBuf[3]);
 445 #endif
 446
 447     // Instruction
 448     if (flag == 1) {
 449         TxBuf[4]=0x04;
 450         sum += TxBuf[4];
 451     } else {
 452         TxBuf[4]=0x03;
 453         sum += TxBuf[4];
 454     }
 455
 456 #ifdef AX12_WRITE_DEBUG
 457     printf("  Instruction : 0x%x\n",TxBuf[4]);
 458 #endif
 459
 460     // Start Address
 461     TxBuf[5] = start;
 462     sum += TxBuf[5];
 463
 464 #ifdef AX12_WRITE_DEBUG
 465     printf("  Start : 0x%x\n",TxBuf[5]);
 466 #endif
 467
 468     // data
 469     for (char i=0; i<bytes ; i++) {
 470         TxBuf[6+i] = data[i];
 471         sum += TxBuf[6+i];
 472
 473 #ifdef AX12_WRITE_DEBUG
 474         printf("  Data : 0x%x\n",TxBuf[6+i]);
 475 #endif
 476
 477     }
 478
 479     // checksum
 480     TxBuf[6+bytes] = 0xFF - sum;
 481
 482 #ifdef AX12_WRITE_DEBUG
 483     printf("  Checksum : 0x%x\n",TxBuf[6+bytes]);
 484 #endif
 485
 486     // Transmit the packet in one burst with no pausing
 487     for (int i = 0; i < (7 + bytes) ; i++) {
 488         _ax12.putc(TxBuf[i]);
 489     }
 490
 491     // Wait for data to transmit
 492     wait (0.00002);
 493
 494     // make sure we have a valid return
 495     Status[4]=0x00;
 496
 497     // we'll only get a reply if it was not broadcast
 498     if (_ID!=0xFE) {
 499
 500
 501         // response packet is always 6 bytes
 502         // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
 503         // timeout is a little more than the time to transmit
 504         // the packet back, i.e. 60 bit periods, round up to 100
 505         int timeout = 0;
 506         int plen = 0;
 507         while ((timeout < 100) && (plen<6)) {
 508
 509             if (_ax12.readable()) {
 510                 Status[plen] = _ax12.getc();
 511                 plen++;
 512                 timeout = 0;
 513             }
 514
 515             // wait for the bit period
 516             wait (1.0/_baud);
 517             timeout++;
 518         }
 519
 520
 521         // Build the TxPacket first in RAM, then we'll send in one go
 522 #ifdef AX12_WRITE_DEBUG
 523         printf("\nStatus Packet\n  Header : 0x%X, 0x%X\n",Status[0],Status[1]);
 524         printf("  ID : %d\n",Status[2]);
 525         printf("  Length : %d\n",Status[3]);
 526         printf("  Error : 0x%x\n",Status[4]);
 527         printf("  Checksum : 0x%x\n",Status[5]);
 528 #endif
 529
 530
 531     }
 532
 533     return(Status[4]); // return error code
 534 }