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 ... ... @@ -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 -=== ===