Changes for page LSS Communication Protocol
Last modified by Eric Nantel on 2025/06/06 07:47
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... ... @@ -1,10 +5,6 @@ 1 -{{toc depth="3"/}} 2 - 3 -= Protocol concepts = 4 - 5 5 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. 6 6 7 -== Session == 3 +=== Session === 8 8 9 9 A "session" is defined as the time between when the servo is powered ON to when it is powered OFF or reset. 10 10 ... ... @@ -46,6 +46,10 @@ 46 46 Action modifiers can only be used with certain commands. 47 47 ))) 48 48 45 +((( 46 + 47 +))) 48 + 49 49 == Configuration Commands == 50 50 51 51 Configuration commands affect the servo's current session* but unlike action commands, configuration commands are written to EEPROM and are retained even if the servo loses power (therefore NOT session specific). Not all action commands have a corresponding configuration and vice versa. Certain configurations are retained for when the servo is used in RC model. More information can be found on the [[LSS - RC PWM page>>doc:LSS - Overview (DEV).LSS - RC PWM.WebHome]]. ... ... @@ -150,10 +150,7 @@ 150 150 | 12|Max **S**peed in **D**egrees| SD| QSD| CSD| ✓| ✓| tenths of degrees per second (ex 248 = 24.8 degrees per second)|QSD: Add modifier "2" for instantaneous speed 151 151 | 13|Max **S**peed in **R**PM| SR| QSR| CSR| ✓| ✓| rpm|QSR: Add modifier "2" for instantaneous speed 152 152 | 14|**A**ngular **S**tiffness| AS| QAS| CAS| ✓| ✓|none|-4 to +4, but suggested values are between 0 to +4 153 -| 15|**A**ngular **H**olding Stiffness|AH|QAH|CAH| | ✓|none|-10 to +10, with default as 0. 154 -|15b|**A**ngular **A**cceleration|AA|QAA|CAA| | ✓|degrees per second squared|Increments of 10 degrees per second squared 155 -|15c|**A**ngular **D**eceleration|AD|QAD|CAD| | ✓|degrees per second squared|Increments of 10 degrees per second squared 156 -|15d|**M**otion **C**ontrol|MC|QMC| | | ✓|none|MC0 to disable motion control, MC1 to enable. Session specific 153 +| 15|//N/A (removed)//| | | | | | | 157 157 | 16|**LED** Color| LED| QLED| CLED| ✓| ✓| none (integer from 1 to 8)|0=OFF 1=RED 2=GREEN 3= BLUE 4=YELLOW 5=CYAN 6=MAGENTA, 7=WHITE 158 158 | 17|**ID** #| | QID| CID| | ✓| none (integer from 0 to 250)|Note: ID 254 is a "broadcast" which all servos respond to 159 159 | 18|**B**aud rate| B| QB| CB| | ✓| none (integer)| ... ... @@ -161,14 +161,13 @@ 161 161 | 20|**F**irst Position (**P**ulse)| | QFP|CFP | ✓| ✓| none | 162 162 | 21|**F**irst Position (**D**egrees)| | QFD|CFD| ✓| ✓| none | 163 163 | 22|**T**arget (**D**egree) **P**osition| | QDT| | | ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)| 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 +| 23|**M**odel| | QM| | | | none (integer)| 166 166 | 24|Serial **N**umber| | QN| | | | none (integer)| 167 167 | 25|**F**irmware version| | QF| | | | none (integer)| 168 168 | 26|**Q**uery (general status)| | Q| | | ✓| none (integer from 1 to 8)| See command description for details 169 169 | 27|**V**oltage| | QV| | | ✓| millivolts (ex 5936 = 5936mV = 5.936V)| 170 -| 28|**T**emperature| | QT| | | ✓| tenths ofdegrees Celsius|Max temp before error: 85°C (servo goes limp)171 -| 29|**C**urrent| | QC| | | ✓| m illiamps (ex 200= 0.2A)|166 +| 28|**T**emperature| | QT| | | ✓| degrees Celsius|Max temp before error: 85°C (servo goes limp) 167 +| 29|**C**urrent| | QC| | | ✓| tenths of Amps (ex 2 = 0.2A)| 172 172 | 30|**RC** Mode| | |CRC| |✓|none|((( 173 173 CRC: Add modifier "1" for RC-position mode. 174 174 CRC: Add modifier "2" for RC-wheel mode. ... ... @@ -179,39 +179,39 @@ 179 179 |32|**DEFAULT**| | | | |✓|none|Revert to firmware default values. See command for details 180 180 |33|**UPDATE**| | | | |✓|none|Update firmware. See command for details. 181 181 182 -= =Details ==178 += Details = 183 183 184 - ======__1. Limp (**L**)__======180 +__1. Limp (**L**)__ 185 185 186 186 Example: #5L<cr> 187 187 188 188 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>. 189 189 190 - ======__2. Halt & Hold (**H**)__======186 +__2. Halt & Hold (**H**)__ 191 191 192 192 Example: #5H<cr> 193 193 194 194 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. 195 195 196 - ======__3. Timed move (**T**)__======192 +__3. Timed move (**T**)__ 197 197 198 198 Example: #5P1500T2500<cr> 199 199 200 200 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. 201 201 202 - ======__4. Speed (**S**)__======198 +__4. Speed (**S**)__ 203 203 204 204 Example: #5P1500S750<cr> 205 205 206 206 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. 207 207 208 - ======__5. (Relative) Move in Degrees (**MD**)__======204 +__5. (Relative) Move in Degrees (**MD**)__ 209 209 210 210 Example: #5MD123<cr> 211 211 212 212 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. 213 213 214 - ======__6. Origin Offset Action (**O**)__======210 +__6. Origin Offset Action (**O**)__ 215 215 216 216 Example: #5O2400<cr> 217 217 ... ... @@ -235,7 +235,7 @@ 235 235 236 236 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. 237 237 238 - ======__7. Angular Range (**AR**)__======234 +__7. Angular Range (**AR**)__ 239 239 240 240 Example: #5AR1800<cr> 241 241 ... ... @@ -259,7 +259,7 @@ 259 259 260 260 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. 261 261 262 - ======__8. Position in Pulse (**P**)__======258 +__8. Position in Pulse (**P**)__ 263 263 264 264 Example: #5P2334<cr> 265 265 ... ... @@ -272,7 +272,7 @@ 272 272 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. 273 273 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). 274 274 275 - ======__9. Position in Degrees (**D**)__======271 +__9. Position in Degrees (**D**)__ 276 276 277 277 Example: #5PD1456<cr> 278 278 ... ... @@ -286,7 +286,7 @@ 286 286 287 287 This means the servo is located at 13.2 degrees. 288 288 289 - ======__10. Wheel Mode in Degrees (**WD**)__======285 +__10. Wheel Mode in Degrees (**WD**)__ 290 290 291 291 Ex: #5WD900<cr> 292 292 ... ... @@ -298,7 +298,7 @@ 298 298 299 299 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). 300 300 301 - ======__11. Wheel Mode in RPM (**WR**)__======297 +__11. Wheel Mode in RPM (**WR**)__ 302 302 303 303 Ex: #5WR40<cr> 304 304 ... ... @@ -310,7 +310,7 @@ 310 310 311 311 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). 312 312 313 - ======__12. Speed in Degrees (**SD**)__======309 +__12. Speed in Degrees (**SD**)__ 314 314 315 315 Ex: #5SD1800<cr> 316 316 ... ... @@ -335,7 +335,7 @@ 335 335 336 336 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. 337 337 338 - ======__13. Speed in RPM (**SR**)__======334 +__13. Speed in RPM (**SR**)__ 339 339 340 340 Ex: #5SD45<cr> 341 341 ... ... @@ -360,7 +360,7 @@ 360 360 361 361 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. 362 362 363 - ======__14. Angular Stiffness (**AS**)__======359 +__14. Angular Stiffness (AS)__ 364 364 365 365 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. 366 366 ... ... @@ -388,40 +388,12 @@ 388 388 389 389 Writes the desired angular stiffness value to memory. 390 390 391 - ======__15. AngularHold Stiffness (**AH**)__======387 +__15. N/A (removed)__ 392 392 393 -Th e angular holdingstiffnessdeterminestheservo'sability to hold a desired positionunderload. Values can be from-10 to10, with the default being 0. Note that negativevalues mean the final position can be easilydeflected.389 +This command has been removed. 394 394 395 -E x:#5AH3<cr>391 +__16. RGB LED (**LED**)__ 396 396 397 -This sets the holding stiffness for servo #5 to 3 for that session. 398 - 399 -Query Angular Hold Stiffness (**QAH**) 400 - 401 -Ex: #5QAH<cr> might return *5QAH3<cr> 402 - 403 -This returns the servo's angular holding stiffness value. 404 - 405 -Configure Angular Hold Stiffness (**CAH**) 406 - 407 -Ex: #5CAH2<cr> 408 - 409 -This writes the angular holding stiffness of servo #5 to 2 to EEPROM 410 - 411 -====== __15b: Angular Acceleration (**AA**)__ ====== 412 - 413 -{More details to come} 414 - 415 -====== __15c: Angular Deceleration (**AD**)__ ====== 416 - 417 -{More details to come} 418 - 419 -====== __15d: Motion Control (**MC**)__ ====== 420 - 421 -{More details to come} 422 - 423 -====== __16. RGB LED (**LED**)__ ====== 424 - 425 425 Ex: #5LED3<cr> 426 426 427 427 This action sets the servo's RGB LED color for that session.The LED can be used for aesthetics, or (based on user code) to provide visual status updates. Using timing can create patterns. ... ... @@ -438,7 +438,7 @@ 438 438 439 439 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. 440 440 441 - ======__17. Identification Number__======409 +__17. Identification Number__ 442 442 443 443 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. 444 444 ... ... @@ -454,7 +454,7 @@ 454 454 455 455 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. 456 456 457 - ======__18. Baud Rate__======425 +__18. Baud Rate__ 458 458 459 459 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. 460 460 \*: 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. ... ... @@ -471,7 +471,7 @@ 471 471 472 472 Sending this command will change the baud rate associated with servo ID 5 to 9600 bits per second. 473 473 474 - ======__19. Gyre Rotation Direction__======442 +__19. Gyre Rotation Direction__ 475 475 476 476 "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). 477 477 ... ... @@ -489,7 +489,7 @@ 489 489 490 490 This changes the gyre direction as described above and also writes to EEPROM. 491 491 492 - ======__20. First / Initial Position (pulse)__======460 +__20. First / Initial Position (pulse)__ 493 493 494 494 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. 495 495 ... ... @@ -505,7 +505,7 @@ 505 505 506 506 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). 507 507 508 - ======__21. First / Initial Position (Degrees)__======476 +__21. First / Initial Position (Degrees)__ 509 509 510 510 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. 511 511 ... ... @@ -521,37 +521,31 @@ 521 521 522 522 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. 523 523 524 - ======__22. Query Target Position in Degrees (**QDT**)__======492 +__22. Query Target Position in Degrees (**QDT**)__ 525 525 526 526 Ex: #5QDT<cr> might return *5QDT6783<cr> 527 527 528 528 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>). 529 529 530 - ======__23. Query ModelString(**QMS**)__======498 +__23. Query Model (**QM**)__ 531 531 532 -Ex: #5QM S<cr> might return *5QMSLSS-HS1cr>500 +Ex: #5QM<cr> might return *5QM11<cr> 533 533 534 -This reply means the servo model LSS-HS1, meaningahigh speed servo, first revision.502 +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) 535 535 536 - ======__23b. QueryModel (**QM**)__======504 +__24. Query Serial Number (**QN**)__ 537 537 538 -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 - 544 544 Ex: #5QN<cr> might return *5QN~_~_<cr> 545 545 546 546 The number in the response is the servo's serial number which is set and cannot be changed. 547 547 548 - ======__25. Query Firmware (**QF**)__======510 +__25. Query Firmware (**QF**)__ 549 549 550 550 Ex: #5QF<cr> might return *5QF11<cr> 551 551 552 552 The integer in the reply represents the firmware version with one decimal, in this example being 1.1 553 553 554 - ======__26. Query Status (**Q**)__======516 +__26. Query Status (**Q**)__ 555 555 556 556 Ex: #5Q<cr> might return *5Q6<cr>, which indicates the motor is holding a position. 557 557 ... ... @@ -568,25 +568,25 @@ 568 568 |ex: *5Q9<cr>|Stuck|Motor cannot perform request movement at current speed setting 569 569 |ex: *5Q10<cr>|Blocked|Similar to stuck, but the motor is at maxiumum duty and still cannot move (i.e.: stalled) 570 570 571 - ======__27. Query Voltage (**QV**)__======533 +__27. Query Voltage (**QV**)__ 572 572 573 -Ex: #5QV<cr> might return *5QV112 00<cr>535 +Ex: #5QV<cr> might return *5QV112<cr> 574 574 575 575 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). 576 576 577 - ======__28. Query Temperature (**QT**)__======539 +__28. Query Temperature (**QT**)__ 578 578 579 579 Ex: #5QT<cr> might return *5QT564<cr> 580 580 581 581 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. 582 582 583 - ======__29. Query Current (**QC**)__======545 +__29. Query Current (**QC**)__ 584 584 585 585 Ex: #5QC<cr> might return *5QC140<cr> 586 586 587 587 The units are in milliamps, so in the example above, the servo is consuming 140mA, or 0.14A. 588 588 589 - ======__30. RC Mode (**CRC**)__======551 +__30. RC Mode (**CRC**)__ 590 590 591 591 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. 592 592 ... ... @@ -598,13 +598,13 @@ 598 598 599 599 EX: #5CRC<cr> 600 600 601 - ======__31. RESET__======563 +__31. RESET__ 602 602 603 603 Ex: #5RESET<cr> or #5RS<cr> 604 604 605 605 This command does a "soft reset" (no power cycle required) and reverts all commands to those stored in EEPROM (i.e. configuration commands). 606 606 607 - ======__32. DEFAULT & CONFIRM__======569 +__32. DEFAULT & CONFIRM__ 608 608 609 609 Ex: #5DEFAULT<cr> 610 610 ... ... @@ -616,7 +616,7 @@ 616 616 617 617 Note that after the CONFIRM command is sent, the servo will automatically perform a RESET. 618 618 619 - ======__33. UPDATE & CONFIRM__======581 +__33. UPDATE & CONFIRM__ 620 620 621 621 Ex: #5UPDATE<cr> 622 622 ... ... @@ -627,3 +627,5 @@ 627 627 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. 628 628 629 629 Note that after the CONFIRM command is sent, the servo will automatically perform a RESET. 592 + 593 +=== ===