Changes for page LSS Communication Protocol
Last modified by Eric Nantel on 2025/06/06 07:47
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... ... @@ -1,6 +1,10 @@ 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 ... ... @@ -157,7 +157,8 @@ 157 157 | 20|**F**irst Position (**P**ulse)| | QFP|CFP | ✓| ✓| none | 158 158 | 21|**F**irst Position (**D**egrees)| | QFD|CFD| ✓| ✓| none | 159 159 | 22|**T**arget (**D**egree) **P**osition| | QDT| | | ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)| 160 -| 23|**M**odel| | QM| | | | none (integer)| 164 +| 23|**M**odel **String**| | QMS| | | | none (string)| Recommended to determine the model| 165 +| 23b|**M**odel| | QM| | | | none (integer)| Returns a raw value representing the three model inputs (36 bit)| 161 161 | 24|Serial **N**umber| | QN| | | | none (integer)| 162 162 | 25|**F**irmware version| | QF| | | | none (integer)| 163 163 | 26|**Q**uery (general status)| | Q| | | ✓| none (integer from 1 to 8)| See command description for details ... ... @@ -174,39 +174,39 @@ 174 174 |32|**DEFAULT**| | | | |✓|none|Revert to firmware default values. See command for details 175 175 |33|**UPDATE**| | | | |✓|none|Update firmware. See command for details. 176 176 177 -= Details = 182 +== Details == 178 178 179 -__1. Limp (**L**)__ 184 +====== __1. Limp (**L**)__ ====== 180 180 181 181 Example: #5L<cr> 182 182 183 183 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>. 184 184 185 -__2. Halt & Hold (**H**)__ 190 +====== __2. Halt & Hold (**H**)__ ====== 186 186 187 187 Example: #5H<cr> 188 188 189 189 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. 190 190 191 -__3. Timed move (**T**)__ 196 +====== __3. Timed move (**T**)__ ====== 192 192 193 193 Example: #5P1500T2500<cr> 194 194 195 195 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. 196 196 197 -__4. Speed (**S**)__ 202 +====== __4. Speed (**S**)__ ====== 198 198 199 199 Example: #5P1500S750<cr> 200 200 201 201 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. 202 202 203 -__5. (Relative) Move in Degrees (**MD**)__ 208 +====== __5. (Relative) Move in Degrees (**MD**)__ ====== 204 204 205 205 Example: #5MD123<cr> 206 206 207 207 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. 208 208 209 -__6. Origin Offset Action (**O**)__ 214 +====== __6. Origin Offset Action (**O**)__ ====== 210 210 211 211 Example: #5O2400<cr> 212 212 ... ... @@ -230,7 +230,7 @@ 230 230 231 231 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. 232 232 233 -__7. Angular Range (**AR**)__ 238 +====== __7. Angular Range (**AR**)__ ====== 234 234 235 235 Example: #5AR1800<cr> 236 236 ... ... @@ -254,7 +254,7 @@ 254 254 255 255 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. 256 256 257 -__8. Position in Pulse (**P**)__ 262 +====== __8. Position in Pulse (**P**)__ ====== 258 258 259 259 Example: #5P2334<cr> 260 260 ... ... @@ -267,7 +267,7 @@ 267 267 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. 268 268 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). 269 269 270 -__9. Position in Degrees (**D**)__ 275 +====== __9. Position in Degrees (**D**)__ ====== 271 271 272 272 Example: #5PD1456<cr> 273 273 ... ... @@ -281,7 +281,7 @@ 281 281 282 282 This means the servo is located at 13.2 degrees. 283 283 284 -__10. Wheel Mode in Degrees (**WD**)__ 289 +====== __10. Wheel Mode in Degrees (**WD**)__ ====== 285 285 286 286 Ex: #5WD900<cr> 287 287 ... ... @@ -293,7 +293,7 @@ 293 293 294 294 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). 295 295 296 -__11. Wheel Mode in RPM (**WR**)__ 301 +====== __11. Wheel Mode in RPM (**WR**)__ ====== 297 297 298 298 Ex: #5WR40<cr> 299 299 ... ... @@ -305,7 +305,7 @@ 305 305 306 306 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). 307 307 308 -__12. Speed in Degrees (**SD**)__ 313 +====== __12. Speed in Degrees (**SD**)__ ====== 309 309 310 310 Ex: #5SD1800<cr> 311 311 ... ... @@ -330,7 +330,7 @@ 330 330 331 331 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. 332 332 333 -__13. Speed in RPM (**SR**)__ 338 +====== __13. Speed in RPM (**SR**)__ ====== 334 334 335 335 Ex: #5SD45<cr> 336 336 ... ... @@ -355,7 +355,7 @@ 355 355 356 356 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. 357 357 358 -__14. Angular Stiffness (**AS**)__ 363 +====== __14. Angular Stiffness (**AS**)__ ====== 359 359 360 360 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. 361 361 ... ... @@ -383,7 +383,7 @@ 383 383 384 384 Writes the desired angular stiffness value to memory. 385 385 386 -__15. Angular Hold Stiffness (**AH**)__ 391 +====== __15. Angular Hold Stiffness (**AH**)__ ====== 387 387 388 388 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. 389 389 ... ... @@ -403,19 +403,19 @@ 403 403 404 404 This writes the angular holding stiffness of servo #5 to 2 to EEPROM 405 405 406 -__15b: Angular Acceleration (**AA**)__ 411 +====== __15b: Angular Acceleration (**AA**)__ ====== 407 407 408 408 {More details to come} 409 409 410 -__15c: Angular Deceleration (**AD**)__ 415 +====== __15c: Angular Deceleration (**AD**)__ ====== 411 411 412 412 {More details to come} 413 413 414 -__15d: Motion Control (**MC**)__ 419 +====== __15d: Motion Control (**MC**)__ ====== 415 415 416 416 {More details to come} 417 417 418 -__16. RGB LED (**LED**)__ 423 +====== __16. RGB LED (**LED**)__ ====== 419 419 420 420 Ex: #5LED3<cr> 421 421 ... ... @@ -433,7 +433,7 @@ 433 433 434 434 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. 435 435 436 -__17. Identification Number__ 441 +====== __17. Identification Number__ ====== 437 437 438 438 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. 439 439 ... ... @@ -449,7 +449,7 @@ 449 449 450 450 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. 451 451 452 -__18. Baud Rate__ 457 +====== __18. Baud Rate__ ====== 453 453 454 454 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. 455 455 \*: 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. ... ... @@ -466,7 +466,7 @@ 466 466 467 467 Sending this command will change the baud rate associated with servo ID 5 to 9600 bits per second. 468 468 469 -__19. Gyre Rotation Direction__ 474 +====== __19. Gyre Rotation Direction__ ====== 470 470 471 471 "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). 472 472 ... ... @@ -484,7 +484,7 @@ 484 484 485 485 This changes the gyre direction as described above and also writes to EEPROM. 486 486 487 -__20. First / Initial Position (pulse)__ 492 +====== __20. First / Initial Position (pulse)__ ====== 488 488 489 489 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. 490 490 ... ... @@ -500,7 +500,7 @@ 500 500 501 501 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). 502 502 503 -__21. First / Initial Position (Degrees)__ 508 +====== __21. First / Initial Position (Degrees)__ ====== 504 504 505 505 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. 506 506 ... ... @@ -516,31 +516,37 @@ 516 516 517 517 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. 518 518 519 -__22. Query Target Position in Degrees (**QDT**)__ 524 +====== __22. Query Target Position in Degrees (**QDT**)__ ====== 520 520 521 521 Ex: #5QDT<cr> might return *5QDT6783<cr> 522 522 523 523 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>). 524 524 525 -__23. Query Model (**QM**)__ 530 +====== __23. Query Model String (**QMS**)__ ====== 526 526 527 -Ex: #5QM<cr> might return *5QM1 1<cr>532 +Ex: #5QMS<cr> might return *5QMSLSS-HS1cr> 528 528 529 -This reply means the servo model is 1 .1, meaning high speed servo, first revision.1=HS (high speed) 2=ST (standard) 3=HT (high torque)534 +This reply means the servo model is LSS-HS1, meaning a high speed servo, first revision. 530 530 531 -__2 4. QuerySerialNumber(**QN**)__536 +====== __23b. Query Model (**QM**)__ ====== 532 532 538 +Ex: #5QM<cr> might return *5QM68702699520cr> 539 + 540 +This reply means the servo model is 0xFFF000000 or 100, meaning a high speed servo, first revision. 541 + 542 +====== __24. Query Serial Number (**QN**)__ ====== 543 + 533 533 Ex: #5QN<cr> might return *5QN~_~_<cr> 534 534 535 535 The number in the response is the servo's serial number which is set and cannot be changed. 536 536 537 -__25. Query Firmware (**QF**)__ 548 +====== __25. Query Firmware (**QF**)__ ====== 538 538 539 539 Ex: #5QF<cr> might return *5QF11<cr> 540 540 541 541 The integer in the reply represents the firmware version with one decimal, in this example being 1.1 542 542 543 -__26. Query Status (**Q**)__ 554 +====== __26. Query Status (**Q**)__ ====== 544 544 545 545 Ex: #5Q<cr> might return *5Q6<cr>, which indicates the motor is holding a position. 546 546 ... ... @@ -557,25 +557,25 @@ 557 557 |ex: *5Q9<cr>|Stuck|Motor cannot perform request movement at current speed setting 558 558 |ex: *5Q10<cr>|Blocked|Similar to stuck, but the motor is at maxiumum duty and still cannot move (i.e.: stalled) 559 559 560 -__27. Query Voltage (**QV**)__ 571 +====== __27. Query Voltage (**QV**)__ ====== 561 561 562 562 Ex: #5QV<cr> might return *5QV11200<cr> 563 563 564 564 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). 565 565 566 -__28. Query Temperature (**QT**)__ 577 +====== __28. Query Temperature (**QT**)__ ====== 567 567 568 568 Ex: #5QT<cr> might return *5QT564<cr> 569 569 570 570 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. 571 571 572 -__29. Query Current (**QC**)__ 583 +====== __29. Query Current (**QC**)__ ====== 573 573 574 574 Ex: #5QC<cr> might return *5QC140<cr> 575 575 576 576 The units are in milliamps, so in the example above, the servo is consuming 140mA, or 0.14A. 577 577 578 -__30. RC Mode (**CRC**)__ 589 +====== __30. RC Mode (**CRC**)__ ====== 579 579 580 580 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. 581 581 ... ... @@ -587,13 +587,13 @@ 587 587 588 588 EX: #5CRC<cr> 589 589 590 -__31. RESET__ 601 +====== __31. RESET__ ====== 591 591 592 592 Ex: #5RESET<cr> or #5RS<cr> 593 593 594 594 This command does a "soft reset" (no power cycle required) and reverts all commands to those stored in EEPROM (i.e. configuration commands). 595 595 596 -__32. DEFAULT & CONFIRM__ 607 +====== __32. DEFAULT & CONFIRM__ ====== 597 597 598 598 Ex: #5DEFAULT<cr> 599 599 ... ... @@ -605,7 +605,7 @@ 605 605 606 606 Note that after the CONFIRM command is sent, the servo will automatically perform a RESET. 607 607 608 -__33. UPDATE & CONFIRM__ 619 +====== __33. UPDATE & CONFIRM__ ====== 609 609 610 610 Ex: #5UPDATE<cr> 611 611 ... ... @@ -616,5 +616,3 @@ 616 616 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. 617 617 618 618 Note that after the CONFIRM command is sent, the servo will automatically perform a RESET. 619 - 620 -=== ===