AX12.cpp

00001 /* mbed AX-12+ Servo Library
00002  *
00003  * Copyright (c) 2010, cstyles (http://mbed.org)
00004  *
00005  * Permission is hereby granted, free of charge, to any person obtaining a copy
00006  * of this software and associated documentation files (the "Software"), to deal
00007  * in the Software without restriction, including without limitation the rights
00008  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009  * copies of the Software, and to permit persons to whom the Software is
00010  * furnished to do so, subject to the following conditions:
00011  *
00012  * The above copyright notice and this permission notice shall be included in
00013  * all copies or substantial portions of the Software.
00014  *
00015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021  * THE SOFTWARE.
00022  */
00023 
00024 #include "AX12.h"
00025 #include "mbed.h"
00026 #include "SerialHalfDuplex.h"
00027 
00028 AX12::AX12(PinName tx, PinName rx, int ID, int baud)
00029         : _ax12(tx,rx) {
00030     _baud = baud;
00031     _ID = ID;
00032     _ax12.baud(_baud);
00033 
00034 }
00035 
00036 // Set the mode of the servo
00037 //  0 = Positional (0-300 degrees)
00038 //  1 = Rotational -1 to 1 speed
00039 int AX12::SetMode(int mode) {
00040 
00041     if (mode == 1) { // set CR
00042         SetCWLimit(0);
00043         SetCCWLimit(0);
00044         SetCRSpeed(0.0);
00045     } else {
00046         SetCWLimit(0);
00047         SetCCWLimit(300);
00048         SetCRSpeed(0.0);
00049     }
00050     return(0);
00051 }
00052 
00053 
00054 // if flag[0] is set, were blocking
00055 // if flag[1] is set, we're registering
00056 // they are mutually exclusive operations
00057 int AX12::SetGoal(int degrees, int flags) {
00058 
00059     char reg_flag = 0;
00060     char data[2];
00061 
00062     // set the flag is only the register bit is set in the flag
00063     if (flags == 0x2) {
00064         reg_flag = 1;
00065     }
00066 
00067     // 1023 / 300 * degrees
00068     short goal = (1023 * degrees) / 300;
00069 #ifdef AX12_DEBUG
00070     printf("SetGoal to 0x%x\n",goal);
00071 #endif
00072 
00073     data[0] = goal & 0xff; // bottom 8 bits
00074     data[1] = goal >> 8;   // top 8 bits
00075 
00076     // write the packet, return the error code
00077     int rVal = write(_ID, AX12_REG_GOAL_POSITION, 2, data, reg_flag);
00078 
00079     if (flags == 1) {
00080         // block until it comes to a halt
00081         while (isMoving()) {}
00082     }
00083     return(rVal);
00084 }
00085 
00086 // Set speed 
00087 int AX12::SetSpeed(int speed) {
00088     char data[2];
00089     
00090     data[0] = speed & 0xff; // bottom 8 bits
00091     data[1] = speed >> 8;   // top 8 bits
00092 
00093     // write the packet, return the error code
00094     int rVal = write(_ID, AX12_REG_MOVING_SPEED, 2, data);
00095     return(rVal);
00096 }
00097 
00098 // Set continuous rotation speed from -1 to 1
00099 int AX12::SetCRSpeed(float speed) {
00100 
00101     // bit 10     = direction, 0 = CCW, 1=CW
00102     // bits 9-0   = Speed
00103     char data[2];
00104 
00105     int goal = (0x3ff * abs(speed));
00106 
00107     // Set direction CW if we have a negative speed
00108     if (speed < 0) {
00109         goal |= (0x1 << 10);
00110     }
00111 
00112     data[0] = goal & 0xff; // bottom 8 bits
00113     data[1] = goal >> 8;   // top 8 bits
00114 
00115     // write the packet, return the error code
00116     int rVal = write(_ID, 0x20, 2, data);
00117 
00118     return(rVal);
00119 }
00120 
00121 
00122 int AX12::SetCWLimit (int degrees) {
00123 
00124     char data[2];
00125 
00126     // 1023 / 300 * degrees
00127     short limit = (1023 * degrees) / 300;
00128 
00129 #ifdef AX12_DEBUG
00130     printf("SetCWLimit to 0x%x\n",limit);
00131 #endif
00132 
00133     data[0] = limit & 0xff; // bottom 8 bits
00134     data[1] = limit >> 8;   // top 8 bits
00135 
00136     // write the packet, return the error code
00137     return (write(_ID, AX12_REG_CW_LIMIT, 2, data));
00138 
00139 }
00140 
00141 int AX12::SetCCWLimit (int degrees) {
00142 
00143     char data[2];
00144 
00145     // 1023 / 300 * degrees
00146     short limit = (1023 * degrees) / 300;
00147 
00148 #ifdef AX12_DEBUG
00149     printf("SetCCWLimit to 0x%x\n",limit);
00150 #endif
00151 
00152     data[0] = limit & 0xff; // bottom 8 bits
00153     data[1] = limit >> 8;   // top 8 bits
00154 
00155     // write the packet, return the error code
00156     return (write(_ID, AX12_REG_CCW_LIMIT, 2, data));
00157 }
00158 
00159 
00160 int AX12::SetID (int CurrentID, int NewID) {
00161 
00162     char data[1];
00163     data[0] = NewID;
00164 
00165 #ifdef AX12_DEBUG
00166     printf("Setting ID from 0x%x to 0x%x\n",CurrentID,NewID);
00167 #endif
00168 
00169     return (write(CurrentID, AX12_REG_ID, 1, data));
00170 
00171 }
00172 
00173 
00174 int AX12::SetBaud (int baud) {
00175 
00176     char data[1];
00177     data[0] = baud;
00178 
00179 #ifdef AX12_DEBUG
00180     printf("Setting Baud rate to %d\n",baud);
00181 #endif
00182 
00183     return (write(0xFE, AX12_REG_BAUD, 1, data));
00184 
00185 }
00186 
00187 
00188 
00189 // return 1 is the servo is still in flight
00190 int AX12::isMoving(void) {
00191 
00192     char data[1];
00193     read(_ID,AX12_REG_MOVING,1,data);
00194     return(data[0]);
00195 }
00196 
00197 
00198 void AX12::trigger(void) {
00199 
00200     char TxBuf[16];
00201     char sum = 0;
00202 
00203 #ifdef AX12_TRIGGER_DEBUG
00204     // Build the TxPacket first in RAM, then we'll send in one go
00205     printf("\nTriggered\n");
00206     printf("\nTrigger Packet\n  Header : 0xFF, 0xFF\n");
00207 #endif
00208 
00209     TxBuf[0] = 0xFF;
00210     TxBuf[1] = 0xFF;
00211 
00212     // ID - Broadcast
00213     TxBuf[2] = 0xFE;
00214     sum += TxBuf[2];
00215 
00216 #ifdef AX12_TRIGGER_DEBUG
00217     printf("  ID : %d\n",TxBuf[2]);
00218 #endif
00219 
00220     // Length
00221     TxBuf[3] = 0x02;
00222     sum += TxBuf[3];
00223 
00224 #ifdef AX12_TRIGGER_DEBUG
00225     printf("  Length %d\n",TxBuf[3]);
00226 #endif
00227 
00228     // Instruction - ACTION
00229     TxBuf[4] = 0x04;
00230     sum += TxBuf[4];
00231 
00232 #ifdef AX12_TRIGGER_DEBUG
00233     printf("  Instruction 0x%X\n",TxBuf[5]);
00234 #endif
00235 
00236     // Checksum
00237     TxBuf[5] = 0xFF - sum;
00238 #ifdef AX12_TRIGGER_DEBUG
00239     printf("  Checksum 0x%X\n",TxBuf[5]);
00240 #endif
00241 
00242     // Transmit the packet in one burst with no pausing
00243     for (int i = 0; i < 6 ; i++) {
00244         _ax12.putc(TxBuf[i]);
00245     }
00246 
00247     // This is a broadcast packet, so there will be no reply
00248     return;
00249 }
00250 
00251 
00252 float AX12::GetPosition(void) {
00253 
00254 #ifdef AX12_DEBUG
00255     printf("\nGetPosition(%d)",_ID);
00256 #endif
00257 
00258     char data[2];
00259 
00260     int ErrorCode = read(_ID, AX12_REG_POSITION, 2, data);
00261     short position = data[0] + (data[1] << 8);
00262     float angle = (position * 300)/1024;
00263 
00264     return (angle);
00265 }
00266 
00267 
00268 float AX12::GetTemp (void) {
00269 
00270 #ifdef AX12_DEBUG
00271     printf("\nGetTemp(%d)",_ID);
00272 #endif
00273 
00274     char data[1];
00275     int ErrorCode = read(_ID, AX12_REG_TEMP, 1, data);
00276     float temp = data[0];
00277     return(temp);
00278 }
00279 
00280 
00281 float AX12::GetVolts (void) {
00282 
00283 #ifdef AX12_DEBUG
00284     printf("\nGetVolts(%d)",_ID);
00285 #endif
00286 
00287     char data[1];
00288     int ErrorCode = read(_ID, AX12_REG_VOLTS, 1, data);
00289     float volts = data[0]/10.0;
00290     return(volts);
00291 }
00292 
00293 
00294 int AX12::read(int ID, int start, int bytes, char* data) {
00295 
00296     char PacketLength = 0x4;
00297     char TxBuf[16];
00298     char sum = 0;
00299     char Status[16];
00300 
00301     Status[4] = 0xFE; // return code
00302 
00303 #ifdef AX12_READ_DEBUG
00304     printf("\nread(%d,0x%x,%d,data)\n",ID,start,bytes);
00305 #endif
00306 
00307     // Build the TxPacket first in RAM, then we'll send in one go
00308 #ifdef AX12_READ_DEBUG
00309     printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
00310 #endif
00311 
00312     TxBuf[0] = 0xff;
00313     TxBuf[1] = 0xff;
00314 
00315     // ID
00316     TxBuf[2] = ID;
00317     sum += TxBuf[2];
00318 
00319 #ifdef AX12_READ_DEBUG
00320     printf("  ID : %d\n",TxBuf[2]);
00321 #endif
00322 
00323     // Packet Length
00324     TxBuf[3] = PacketLength;    // Length = 4 ; 2 + 1 (start) = 1 (bytes)
00325     sum += TxBuf[3];            // Accululate the packet sum
00326 
00327 #ifdef AX12_READ_DEBUG
00328     printf("  Length : 0x%x\n",TxBuf[3]);
00329 #endif
00330 
00331     // Instruction - Read
00332     TxBuf[4] = 0x2;
00333     sum += TxBuf[4];
00334 
00335 #ifdef AX12_READ_DEBUG
00336     printf("  Instruction : 0x%x\n",TxBuf[4]);
00337 #endif
00338 
00339     // Start Address
00340     TxBuf[5] = start;
00341     sum += TxBuf[5];
00342 
00343 #ifdef AX12_READ_DEBUG
00344     printf("  Start Address : 0x%x\n",TxBuf[5]);
00345 #endif
00346 
00347     // Bytes to read
00348     TxBuf[6] = bytes;
00349     sum += TxBuf[6];
00350 
00351 #ifdef AX12_READ_DEBUG
00352     printf("  No bytes : 0x%x\n",TxBuf[6]);
00353 #endif
00354 
00355     // Checksum
00356     TxBuf[7] = 0xFF - sum;
00357 #ifdef AX12_READ_DEBUG
00358     printf("  Checksum : 0x%x\n",TxBuf[7]);
00359 #endif
00360 
00361     // Transmit the packet in one burst with no pausing
00362     for (int i = 0; i<8 ; i++) {
00363         _ax12.putc(TxBuf[i]);
00364     }
00365 
00366     // Wait for the bytes to be transmitted
00367     wait (0.00002);
00368 
00369     // Skip if the read was to the broadcast address
00370     if (_ID != 0xFE) {
00371 
00372 
00373 
00374         // response packet is always 6 + bytes
00375         // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
00376         // timeout is a little more than the time to transmit
00377         // the packet back, i.e. (6+bytes)*10 bit periods
00378 
00379         int timeout = 0;
00380         int plen = 0;
00381         while ((timeout < ((6+bytes)*10)) && (plen<(6+bytes))) {
00382 
00383             if (_ax12.readable()) {
00384                 Status[plen] = _ax12.getc();
00385                 plen++;
00386                 timeout = 0;
00387             }
00388 
00389             // wait for the bit period
00390             wait (1.0/_baud);
00391             timeout++;
00392         }
00393 
00394         if (timeout == ((6+bytes)*10) ) {
00395             return(-1);
00396         }
00397 
00398         // Copy the data from Status into data for return
00399         for (int i=0; i < Status[3]-2 ; i++) {
00400             data[i] = Status[5+i];
00401         }
00402 
00403 #ifdef AX12_READ_DEBUG
00404         printf("\nStatus Packet\n");
00405         printf("  Header : 0x%x\n",Status[0]);
00406         printf("  Header : 0x%x\n",Status[1]);
00407         printf("  ID : 0x%x\n",Status[2]);
00408         printf("  Length : 0x%x\n",Status[3]);
00409         printf("  Error Code : 0x%x\n",Status[4]);
00410 
00411         for (int i=0; i < Status[3]-2 ; i++) {
00412             printf("  Data : 0x%x\n",Status[5+i]);
00413         }
00414 
00415         printf("  Checksum : 0x%x\n",Status[5+(Status[3]-2)]);
00416 #endif
00417 
00418     } // if (ID!=0xFE)
00419 
00420     return(Status[4]);
00421 }
00422 
00423 
00424 int AX12::write(int ID, int start, int bytes, char* data, int flag) {
00425 // 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum
00426 
00427     char TxBuf[16];
00428     char sum = 0;
00429     char Status[6];
00430 
00431 #ifdef AX12_WRITE_DEBUG
00432     printf("\nwrite(%d,0x%x,%d,data,%d)\n",ID,start,bytes,flag);
00433 #endif
00434 
00435     // Build the TxPacket first in RAM, then we'll send in one go
00436 #ifdef AX12_WRITE_DEBUG
00437     printf("\nInstruction Packet\n  Header : 0xFF, 0xFF\n");
00438 #endif
00439 
00440     TxBuf[0] = 0xff;
00441     TxBuf[1] = 0xff;
00442 
00443     // ID
00444     TxBuf[2] = ID;
00445     sum += TxBuf[2];
00446 
00447 #ifdef AX12_WRITE_DEBUG
00448     printf("  ID : %d\n",TxBuf[2]);
00449 #endif
00450 
00451     // packet Length
00452     TxBuf[3] = 3+bytes;
00453     sum += TxBuf[3];
00454 
00455 #ifdef AX12_WRITE_DEBUG
00456     printf("  Length : %d\n",TxBuf[3]);
00457 #endif
00458 
00459     // Instruction
00460     if (flag == 1) {
00461         TxBuf[4]=0x04;
00462         sum += TxBuf[4];
00463     } else {
00464         TxBuf[4]=0x03;
00465         sum += TxBuf[4];
00466     }
00467 
00468 #ifdef AX12_WRITE_DEBUG
00469     printf("  Instruction : 0x%x\n",TxBuf[4]);
00470 #endif
00471 
00472     // Start Address
00473     TxBuf[5] = start;
00474     sum += TxBuf[5];
00475 
00476 #ifdef AX12_WRITE_DEBUG
00477     printf("  Start : 0x%x\n",TxBuf[5]);
00478 #endif
00479 
00480     // data
00481     for (char i=0; i<bytes ; i++) {
00482         TxBuf[6+i] = data[i];
00483         sum += TxBuf[6+i];
00484 
00485 #ifdef AX12_WRITE_DEBUG
00486         printf("  Data : 0x%x\n",TxBuf[6+i]);
00487 #endif
00488 
00489     }
00490 
00491     // checksum
00492     TxBuf[6+bytes] = 0xFF - sum;
00493 
00494 #ifdef AX12_WRITE_DEBUG
00495     printf("  Checksum : 0x%x\n",TxBuf[6+bytes]);
00496 #endif
00497 
00498     // Transmit the packet in one burst with no pausing
00499     for (int i = 0; i < (7 + bytes) ; i++) {
00500         _ax12.putc(TxBuf[i]);
00501     }
00502 
00503     // Wait for data to transmit
00504     wait (0.00002);
00505 
00506     // make sure we have a valid return
00507     Status[4]=0x00;
00508 
00509     // we'll only get a reply if it was not broadcast
00510     if (_ID!=0xFE) {
00511 
00512 
00513         // response packet is always 6 bytes
00514         // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
00515         // timeout is a little more than the time to transmit
00516         // the packet back, i.e. 60 bit periods, round up to 100
00517         int timeout = 0;
00518         int plen = 0;
00519         while ((timeout < 100) && (plen<6)) {
00520 
00521             if (_ax12.readable()) {
00522                 Status[plen] = _ax12.getc();
00523                 plen++;
00524                 timeout = 0;
00525             }
00526 
00527             // wait for the bit period
00528             wait (1.0/_baud);
00529             timeout++;
00530         }
00531 
00532 
00533         // Build the TxPacket first in RAM, then we'll send in one go
00534 #ifdef AX12_WRITE_DEBUG
00535         printf("\nStatus Packet\n  Header : 0x%X, 0x%X\n",Status[0],Status[1]);
00536         printf("  ID : %d\n",Status[2]);
00537         printf("  Length : %d\n",Status[3]);
00538         printf("  Error : 0x%x\n",Status[4]);
00539         printf("  Checksum : 0x%x\n",Status[5]);
00540 #endif
00541 
00542 
00543     }
00544 
00545     return(Status[4]); // return error code
00546 }