Last modified by Eric Nantel on 2025/06/06 07:47

From version < 64.1 >
edited by RB1
on 2018/10/22 13:32
To version < 64.16 >
edited by RB1
on 2018/11/19 09:31
< >
Change comment: There is no comment for this version

Summary

Details

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Content
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1 +{{toc depth="3"/}}
2 +
3 += Protocol concepts =
4 +
1 1  The Lynxmotion Smart Servo (LSS) protocol was created in order to be as simple and straightforward as possible from a user perspective, while at the same time trying to stay compact and robust yet highly versatile. Almost everything one might expect to be able to configure for a smart servo motor is available.
2 2  
3 -=== Session ===
7 +== Session ==
4 4  
5 5  A "session" is defined as the time between when the servo is powered ON to when it is powered OFF or reset.
6 6  
... ... @@ -175,39 +175,39 @@
175 175  |32|**DEFAULT**| | | | |✓|none|Revert to firmware default values. See command for details
176 176  |33|**UPDATE**| | | | |✓|none|Update firmware. See command for details.
177 177  
178 -= Details =
182 +== Details ==
179 179  
180 -__1. Limp (**L**)__
184 +====== __1. Limp (**L**)__ ======
181 181  
182 182  Example: #5L<cr>
183 183  
184 184  This action causes the servo to go "limp". The microcontroller will still be powered, but the motor will not. As an emergency safety feature, should the robot not be doing what it is supposed to or risks damage, use the broadcast ID to set all servos limp #254L<cr>.
185 185  
186 -__2. Halt & Hold (**H**)__
190 +====== __2. Halt & Hold (**H**)__ ======
187 187  
188 188  Example: #5H<cr>
189 189  
190 190  This action overrides whatever the servo might be doing at the time the command is received (accelerating, moving continuously etc.) and causes it to stop immediately and hold that position.
191 191  
192 -__3. Timed move (**T**)__
196 +====== __3. Timed move (**T**)__ ======
193 193  
194 194  Example: #5P1500T2500<cr>
195 195  
196 196  Timed move can be used only as a modifier for a position (P) action. The units are in milliseconds, so a timed move of 2500 milliseconds would cause the servo to rotate from its current position to the desired position in 2.5 seconds. This command is in place to ensure backwards compatibility with the SSC-32 / 32U protocol.
197 197  
198 -__4. Speed (**S**)__
202 +====== __4. Speed (**S**)__ ======
199 199  
200 200  Example: #5P1500S750<cr>
201 201  
202 202  This command is a modifier only for a position (P) action and determines the speed of the move in microseconds per second. A speed of 750 microseconds would cause the servo to rotate from its current position to the desired position at a speed of 750 microseconds per second. This command is in place to ensure backwards compatibility with the SSC-32 / 32U protocol.
203 203  
204 -__5. (Relative) Move in Degrees (**MD**)__
208 +====== __5. (Relative) Move in Degrees (**MD**)__ ======
205 205  
206 206  Example: #5MD123<cr>
207 207  
208 208  The relative move command causes the servo to read its current position and move the specified number of tenths of degrees in the corresponding position. For example if the servo is set to rotate CW (default) and an MD command of 123 is sent to the servo, it will cause the servo to rotate clockwise by 12.3 degrees. Negative commands would cause the servo to rotate in the opposite configured direction.
209 209  
210 -__6. Origin Offset Action (**O**)__
214 +====== __6. Origin Offset Action (**O**)__ ======
211 211  
212 212  Example: #5O2400<cr>
213 213  
... ... @@ -231,7 +231,7 @@
231 231  
232 232  This command allows you to change the origin of the servo in relation to the factory zero position in EEPROM. The setting will be saved upon servo reset / power cycle. Origin offset configuration commands are not cumulative and always relate to factory zero. The new origin is also used in RC mode.
233 233  
234 -__7. Angular Range (**AR**)__
238 +====== __7. Angular Range (**AR**)__ ======
235 235  
236 236  Example: #5AR1800<cr>
237 237  
... ... @@ -255,7 +255,7 @@
255 255  
256 256  This command allows you to change the total angular range of the servo in tenths of degrees in EEPROM. The setting will be saved upon servo reset / power cycle.
257 257  
258 -__8. Position in Pulse (**P**)__
262 +====== __8. Position in Pulse (**P**)__ ======
259 259  
260 260  Example: #5P2334<cr>
261 261  
... ... @@ -268,7 +268,7 @@
268 268  This command queries the current angular position in PWM "units". The user must take into consideration that the response includes any angular range and origin configurations in order to determine the actual angle. 
269 269  Valid values for QP are {-500, [500, 2500], -2500}. Values outside the [500, 2500] range are given a negative corresponding end point value to indicate they are out of bounds (note that if the servo is physically located at one of the endpoints, it may return a negative number if it is a fraction of a degree beyond the position).
270 270  
271 -__9. Position in Degrees (**D**)__
275 +====== __9. Position in Degrees (**D**)__ ======
272 272  
273 273  Example: #5PD1456<cr>
274 274  
... ... @@ -282,7 +282,7 @@
282 282  
283 283  This means the servo is located at 13.2 degrees.
284 284  
285 -__10. Wheel Mode in Degrees (**WD**)__
289 +====== __10. Wheel Mode in Degrees (**WD**)__ ======
286 286  
287 287  Ex: #5WD900<cr>
288 288  
... ... @@ -294,7 +294,7 @@
294 294  
295 295  The servo replies with the angular speed in tenths of degrees per second. A negative sign would indicate the opposite direction (for factory default a negative value would be counter clockwise).
296 296  
297 -__11. Wheel Mode in RPM (**WR**)__
301 +====== __11. Wheel Mode in RPM (**WR**)__ ======
298 298  
299 299  Ex: #5WR40<cr>
300 300  
... ... @@ -306,7 +306,7 @@
306 306  
307 307  The servo replies with the angular speed in rpm. A negative sign would indicate the opposite direction (for factory default a negative value would be counter clockwise).
308 308  
309 -__12. Speed in Degrees (**SD**)__
313 +====== __12. Speed in Degrees (**SD**)__ ======
310 310  
311 311  Ex: #5SD1800<cr>
312 312  
... ... @@ -331,7 +331,7 @@
331 331  
332 332  Using the CSD command sets the servo's maximum speed which is saved in EEPROM. In the example above, the servo's maximum speed will be set to 180.0 degrees per second. When the servo is powered on (or after a reset), the CSD value is used. Note that CSD and CSR (described below) are effectively the same, but allow the user to specify the speed in either unit. The last command (either CSR or CSD) is what the servo uses for that session.
333 333  
334 -__13. Speed in RPM (**SR**)__
338 +====== __13. Speed in RPM (**SR**)__ ======
335 335  
336 336  Ex: #5SD45<cr>
337 337  
... ... @@ -356,7 +356,7 @@
356 356  
357 357  Using the CSR command sets the servo's maximum speed which is saved in EEPROM. In the example above, the servo's maximum speed will be set to 45rpm. When the servo is powered on (or after a reset), the CSR value is used. Note that CSD and CSR are effectively the same, but allow the user to specify the speed in either unit. The last command (either CSR or CSD) is what the servo uses for that session.
358 358  
359 -__14. Angular Stiffness (**AS**)__
363 +====== __14. Angular Stiffness (**AS**)__ ======
360 360  
361 361  The servo's rigidity / angular stiffness can be thought of as (though not identical to) a damped spring in which the value affects the stiffness and embodies how much, and how quickly the servo tried keep the requested position against changes.
362 362  
... ... @@ -384,7 +384,7 @@
384 384  
385 385  Writes the desired angular stiffness value to memory.
386 386  
387 -__15. Angular Hold Stiffness (**AH**)__
391 +====== __15. Angular Hold Stiffness (**AH**)__ ======
388 388  
389 389  The angular holding stiffness determines the servo's ability to hold a desired position under load. Values can be from -10 to 10, with the default being 0. Note that negative values mean the final position can be easily deflected.
390 390  
... ... @@ -404,19 +404,19 @@
404 404  
405 405  This writes the angular holding stiffness of servo #5 to 2 to EEPROM
406 406  
407 -__15b: Angular Acceleration (**AA**)__
411 +====== __15b: Angular Acceleration (**AA**)__ ======
408 408  
409 409  {More details to come}
410 410  
411 -__15c: Angular Deceleration (**AD**)__
415 +====== __15c: Angular Deceleration (**AD**)__ ======
412 412  
413 413  {More details to come}
414 414  
415 -__15d: Motion Control (**MC**)__
419 +====== __15d: Motion Control (**MC**)__ ======
416 416  
417 417  {More details to come}
418 418  
419 -__16. RGB LED (**LED**)__
423 +====== __16. RGB LED (**LED**)__ ======
420 420  
421 421  Ex: #5LED3<cr>
422 422  
... ... @@ -434,7 +434,7 @@
434 434  
435 435  Configuring the LED color via the CLED command sets the startup color of the servo after a reset or power cycle. Note that it also changes the session's LED color immediately as well.
436 436  
437 -__17. Identification Number__
441 +====== __17. Identification Number__ ======
438 438  
439 439  A servo's identification number cannot be set "on the fly" and must be configured via the CID command described below. The factory default ID number for all servos is 0. Since smart servos are intended to be daisy chained, in order to respond differently from one another, the user must set different identification numbers. Servos with the same ID and baud rate will all receive and react to the same commands.
440 440  
... ... @@ -450,7 +450,7 @@
450 450  
451 451  Setting a servo's ID in EEPROM is done via the CID command. All servos connected to the same serial bus will be assigned that ID. In most situations each servo must be set a unique ID, which means each servo must be connected individually to the serial bus and receive a unique CID number. It is best to do this before the servos are added to an assembly. Numbered stickers are provided to distinguish each servo after their ID is set, though you are free to use whatever alternative method you like.
452 452  
453 -__18. Baud Rate__
457 +====== __18. Baud Rate__ ======
454 454  
455 455  A servo's baud rate cannot be set "on the fly" and must be configured via the CB command described below. The factory default baud rate for all servos is 9600. Since smart servos are intended to be daisy chained, in order to respond to the same serial bus, all servos in that project should ideally be set to the same baud rate. Setting different baud rates will have the servos respond differently and may create issues. Available baud rates are: 9.6 kbps, 19.2 kbps, 38.4 kbps, 57.6 kbps, 115.2 kbps, 230.4 kbps, 250.0 kbps, 460.8 kbps, 500.0 kbps, 750.0 kbps*, 921.6 kbps*. Servos are shipped with a baud rate set to 9600. The baud rates are currently restricted to those above.
456 456  \*: Current tests reveal baud rates above 500 kbps are unstable and can cause timeouts. Please keep this in mind if using those / testing them out.
... ... @@ -467,7 +467,7 @@
467 467  
468 468  Sending this command will change the baud rate associated with servo ID 5 to 9600 bits per second.
469 469  
470 -__19. Gyre Rotation Direction__
474 +====== __19. Gyre Rotation Direction__ ======
471 471  
472 472  "Gyre" is defined as a circular course or motion. The effect of changing the gyre direction is as if you were to use a mirror image of a circle. CW = 1; CCW = -1. The factory default is clockwise (CW).
473 473  
... ... @@ -485,7 +485,7 @@
485 485  
486 486  This changes the gyre direction as described above and also writes to EEPROM.
487 487  
488 -__20. First / Initial Position (pulse)__
492 +====== __20. First / Initial Position (pulse)__ ======
489 489  
490 490  In certain cases, a user might want to have the servo move to a specific angle upon power up. We refer to this as "first position". The factory default has no first position value stored in EEPROM and therefore upon power up, the servo remains limp until a position (or hold command) is assigned. FP and FD are different in that FP is used for RC mode only, whereas FD is used for smart mode only.
491 491  
... ... @@ -501,7 +501,7 @@
501 501  
502 502  This configuration command means the servo, when set to RC mode, will immediately move to an angle equivalent to having received an RC pulse of 1550 microseconds upon power up. Sending a CFP command without a number results in the servo remaining limp upon power up (i.e. disabled).
503 503  
504 -__21. First / Initial Position (Degrees)__
508 +====== __21. First / Initial Position (Degrees)__ ======
505 505  
506 506  In certain cases, a user might want to have the servo move to a specific angle upon power up. We refer to this as "first position". The factory default has no first position value stored in EEPROM and therefore upon power up, the servo remains limp until a position (or hold command) is assigned. FP and FD are different in that FP is used for RC mode only, whereas FD is used for smart mode only.
507 507  
... ... @@ -517,37 +517,37 @@
517 517  
518 518  This configuration command means the servo, when set to smart mode, will immediately move to 6.4 degrees upon power up. Sending a CFD command without a number results in the servo remaining limp upon power up.
519 519  
520 -__22. Query Target Position in Degrees (**QDT**)__
524 +====== __22. Query Target Position in Degrees (**QDT**)__ ======
521 521  
522 522  Ex: #5QDT<cr> might return *5QDT6783<cr>
523 523  
524 524  The query target position command returns the target angle during and after an action which results in a rotation of the servo horn. In the example above, the servo is rotating to a virtual position of 678.3 degrees. Should the servo not have a target position or be in wheel mode, it will respond without a number (Ex: *5QDT<cr>).
525 525  
526 -__23. Query Model String (**QMS**)__
530 +====== __23. Query Model String (**QMS**)__ ======
527 527  
528 528  Ex: #5QMS<cr> might return *5QMSLSS-HS1cr>
529 529  
530 530  This reply means the servo model is LSS-HS1, meaning a high speed servo, first revision.
531 531  
532 -__23b. Query Model (**QM**)__
536 +====== __23b. Query Model (**QM**)__ ======
533 533  
534 534  Ex: #5QM<cr> might return *5QM68702699520cr>
535 535  
536 536  This reply means the servo model is 0xFFF000000 or 100, meaning a high speed servo, first revision.
537 537  
538 -__24. Query Serial Number (**QN**)__
542 +====== __24. Query Serial Number (**QN**)__ ======
539 539  
540 540  Ex: #5QN<cr> might return *5QN~_~_<cr>
541 541  
542 542  The number in the response is the servo's serial number which is set and cannot be changed.
543 543  
544 -__25. Query Firmware (**QF**)__
548 +====== __25. Query Firmware (**QF**)__ ======
545 545  
546 546  Ex: #5QF<cr> might return *5QF11<cr>
547 547  
548 548  The integer in the reply represents the firmware version with one decimal, in this example being 1.1
549 549  
550 -__26. Query Status (**Q**)__
554 +====== __26. Query Status (**Q**)__ ======
551 551  
552 552  Ex: #5Q<cr> might return *5Q6<cr>, which indicates the motor is holding a position.
553 553  
... ... @@ -564,25 +564,25 @@
564 564  |ex: *5Q9<cr>|Stuck|Motor cannot perform request movement at current speed setting
565 565  |ex: *5Q10<cr>|Blocked|Similar to stuck, but the motor is at maxiumum duty and still cannot move (i.e.: stalled)
566 566  
567 -__27. Query Voltage (**QV**)__
571 +====== __27. Query Voltage (**QV**)__ ======
568 568  
569 569  Ex: #5QV<cr> might return *5QV11200<cr>
570 570  
571 571  The number returned has one decimal, so in the case above, servo with ID 5 has an input voltage of 11.2V (perhaps a three cell LiPo battery).
572 572  
573 -__28. Query Temperature (**QT**)__
577 +====== __28. Query Temperature (**QT**)__ ======
574 574  
575 575  Ex: #5QT<cr> might return *5QT564<cr>
576 576  
577 577  The units are in tenths of degrees Celcius, so in the example above, the servo's internal temperature is 56.4 degrees C. To convert from degrees Celcius to degrees Farenheit, multiply by 1.8 and add 32. Therefore 56.4C = 133.52F.
578 578  
579 -__29. Query Current (**QC**)__
583 +====== __29. Query Current (**QC**)__ ======
580 580  
581 581  Ex: #5QC<cr> might return *5QC140<cr>
582 582  
583 583  The units are in milliamps, so in the example above, the servo is consuming 140mA, or 0.14A.
584 584  
585 -__30. RC Mode (**CRC**)__
589 +====== __30. RC Mode (**CRC**)__ ======
586 586  
587 587  This command puts the servo into RC mode (position or continuous), where it will only respond to RC pulses. Note that because this is the case, the servo will no longer accept serial commands. The servo can be placed back into smart mode by using the button menu.
588 588  
... ... @@ -594,13 +594,13 @@
594 594  
595 595  EX: #5CRC<cr>
596 596  
597 -__31. RESET__
601 +====== __31. RESET__ ======
598 598  
599 599  Ex: #5RESET<cr> or #5RS<cr>
600 600  
601 601  This command does a "soft reset" (no power cycle required) and reverts all commands to those stored in EEPROM (i.e. configuration commands).
602 602  
603 -__32. DEFAULT & CONFIRM__
607 +====== __32. DEFAULT & CONFIRM__ ======
604 604  
605 605  Ex: #5DEFAULT<cr>
606 606  
... ... @@ -612,7 +612,7 @@
612 612  
613 613  Note that after the CONFIRM command is sent, the servo will automatically perform a RESET.
614 614  
615 -__33. UPDATE & CONFIRM__
619 +====== __33. UPDATE & CONFIRM__ ======
616 616  
617 617  Ex: #5UPDATE<cr>
618 618  
... ... @@ -623,5 +623,3 @@
623 623  Since it it not common to have to update firmware, a confirmation command is needed after an UPDATE command is sent. Should any command other than CONFIRM be received by the servo after the firmware command has been received, it will leave the firmware action.
624 624  
625 625  Note that after the CONFIRM command is sent, the servo will automatically perform a RESET.
626 -
627 -=== ===
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