LSS - Communication Protocol

= Protocol concepts =

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.

4

5

== Session ==

6

7

A "session" is defined as the time between when the servo is powered ON to when it is powered OFF or reset.

8

9

== Action Commands ==

10

11

Action commands are sent serially to the servo's Rx pin and must be set in the following format:

12

13

1. Start with a number sign # (U+0023)

14

1. Servo ID number as an integer

15

1. Action command (one to three letters, no spaces, capital or lower case)

16

1. Action value in the correct units with no decimal

17

1. End with a control / carriage return '<cr>'

(((

Ex: #5PD1443<cr>

Move servo with ID #5 to a position of 144.3 degrees.

23

24

Action commands cannot be combined with query commands, and only one action command can be sent at a time.

25

26

Action commands are session-specific, therefore once a servo is power cycled, it will not have any "memory" of previous actions or virtual positions (as described at the bottom of this page).

27

28

=== Action Modifiers ===

29

30

Two commands can be used as action modifiers only: Timed Move and Speed. The format is:

31

32

1. Start with a number sign # (U+0023)

33

1. Servo ID number as an integer

34

1. Action command (one to three letters, no spaces, capital or lower case)

35

1. Action value in the correct units with no decimal

36

1. Modifier command (one letter)

37

1. Modifier value in the correct units with no decimal

38

1. End with a control / carriage return '<cr>'

Ex: #5P1456T1263<cr>

Results in the servo rotating from the current angular position to a pulse position of 1456 in 1263 milliseconds.

43

44

Action modifiers can only be used with certain commands.

45

)))

46

47

== Configuration Commands ==

48

49

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]].

50

51

1. Start with a number sign # (U+0023)

52

1. Servo ID number as an integer

53

1. Configuration command (two to three letters, no spaces, capital or lower case)

54

1. Configuration value in the correct units with no decimal

55

1. End with a control / carriage return '<cr>'

Ex: #5CO-50<cr>

Assigns an absolute origin offset of -5.0 degrees (with respect to factory origin) to servo #5 and changes the offset for that session to -5.0 degrees.

60

61

Configuration commands are not cumulative, in that if two configurations are sent at any time, only the last configuration is used and stored.

62

63

*Important Note: the one exception is the baud rate - the servo's current session retains the given baud rate. The new baud rate will only be in place when the servo is power cycled.

== Query Commands ==

Query commands are sent serially to the servo's Rx pin and must be set in the following format:

68

69

1. Start with a number sign # (U+0023)

70

1. Servo ID number as an integer

71

1. Query command (one to three letters, no spaces, capital or lower case)

72

1. End with a control / carriage return '<cr>'

73

74

(((

75

Ex: #5QD<cr>Query position in degrees for servo #5

)))

(((

The query will return a value via the Tx pin with the following format:

80

81

1. Start with an asterisk (U+002A)

82

1. Servo ID number as an integer

83

1. Query command (one to three letters, no spaces, capital letters)

84

1. The reported value in the units described, no decimals.

85

1. End with a control / carriage return '<cr>'

(((

Ex: *5QD1443<cr>

)))

Indicates that servo #5 is currently at 144.3 degrees.

92

93

**Session vs Configuration Query**

94

95

By default, the query command returns the sessions' value; should no action commands have been sent to change, it will return the value saved in EEPROM from the last configuration command.

96

97

In order to query the value in EEPROM, add a '1' to the query command.

98

99

Ex: #5CSR20<cr> sets the maximum speed for servo #5 to 20rpm upon RESET (explained below).

100

101

After RESET: #5SR4<cr> sets the session's speed to 4rpm.

102

103

#5QSR<cr> would return *5QSR4<cr> which represents the value for that session.

104

105

#5QSR1<cr> would return *5QSR20<cr> which represents the value in EEPROM

106

107

=== Virtual Angular Position ===

{In progress}

A "virtual position" is one which allows for multiple rotations of the output horn, moving the center position and more. The "absolute position" would be the angle of the output shaft with respect to 360.0 degrees.

112

113

[[image:LSS-servo-positions.jpg]]

114

115

Example: Gyre direction / rotation is positive (clockwise), and origin offset has not been modified. Each square represents 30 degrees.

116

117

#1D-300<cr> The servo is sent a command to move to -30.0 degrees (green arrow)

118

119

#1D2100<cr> This second position command is sent to the servo, which moves it to 210.0 degrees (orange arrow)

120

121

#1D-4200<cr> This next command rotates the servo counterclockwise to a position of -420 degrees (red arrow), which means one full rotation of 360 degrees, stopping at an absolute position of 60.0 degrees (420.0-360.0), with a virtual position of -420.0 degrees.

122

123

Although the final physical position would be the same as if the servo were commanded to move to -60.0 degrees, the servo is in fact at -420.0 degrees.

124

125

#1D4800<cr> This new command is sent which would then cause the servo to rotate from -420.0 degrees to 480.0 degrees (blue arrow), which would be a total of 900 degrees of clockwise rotation, or 2.5 complete rotations.

126

127

#1D3300<cr> would cause the servo to rotate from 480.0 degrees to 330.0 degrees (yellow arrow).

128

129

If / once the servo loses power or is power cycled, it also loses the virtual position associated with that session. For example, if the virtual position was 480.0 degrees before power is cycled, upon power up the servo's position will be read as +120.0 degrees from zero (assuming center position has not been modified).

)))

= Command List =

| 1|**L**imp| L| | | | ✓| none|

136

| 2|**H**alt & Hold| H| | | | ✓| none|

137

| 3|**T**imed move| T| | | | ✓| milliseconds| Modifier only

138

| 4|**S**peed| S| | | | ✓| microseconds / second| Modifier only

139

| 5|**M**ove in **D**egrees (relative)| MD| | | | ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|

140

| 6|**O**rigin Offset| O| QO| CO| ✓| ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|

141

| 7|**A**ngular **R**ange| AR| QAR| CAR| ✓| ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|

142

| 8|Position in **P**ulse| P| QP| | | ✓| microseconds|(((

143

See details below

144

)))

145

| 9|Position in **D**egrees| D| QD| | | ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|

146

| 10|**W**heel mode in **D**egrees| WD| QWD| | | ✓| tenths of degrees per second (ex 248 = 24.8 degrees per second)|

147

| 11|**W**heel mode in **R**PM| WR| QWR| | | ✓| rpm|

148

| 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

149

| 13|Max **S**peed in **R**PM| SR| QSR| CSR| ✓| ✓| rpm|QSR: Add modifier "2" for instantaneous speed

150

| 14|**A**ngular **S**tiffness| AS| QAS| CAS| ✓| ✓|none|-4 to +4, but suggested values are between 0 to +4

151

| 15|**A**ngular **H**olding Stiffness|AH|QAH|CAH| | ✓|none|-10 to +10, with default as 0.

152

|15b|**A**ngular **A**cceleration|AA|QAA|CAA| | ✓|degrees per second squared|Increments of 10 degrees per second squared

153

|15c|**A**ngular **D**eceleration|AD|QAD|CAD| | ✓|degrees per second squared|Increments of 10 degrees per second squared

154

|15d|**M**otion **C**ontrol|MC|QMC| | | ✓|none|MC0 to disable motion control, MC1 to enable. Session specific

155

| 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

156

| 17|**ID** #| | QID| CID| | ✓| none (integer from 0 to 250)|Note: ID 254 is a "broadcast" which all servos respond to

157

| 18|**B**aud rate| B| QB| CB| | ✓| none (integer)|

158

| 19|**G**yre direction (**G**)| G| QG| CG| ✓| ✓| none | Gyre / rotation direction where 1= CW (clockwise) -1 = CCW (counter-clockwise)

159

| 20|**F**irst Position (**P**ulse)| | QFP|CFP | ✓| ✓| none |

160

| 21|**F**irst Position (**D**egrees)| | QFD|CFD| ✓| ✓| none |

161

| 22|**T**arget (**D**egree) **P**osition| | QDT| | | ✓| tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|

162

163

164

| 24|Serial **N**umber| | QN| | | | none (integer)|

165

| 25|**F**irmware version| | QF| | | | none (integer)|

166

| 26|**Q**uery (general status)| | Q| | | ✓| none (integer from 1 to 8)| See command description for details

167

| 27|**V**oltage| | QV| | | ✓| millivolts (ex 5936 = 5936mV = 5.936V)|

168

| 28|**T**emperature| | QT| | | ✓| tenths of degrees Celsius|Max temp before error: 85°C (servo goes limp)

169

| 29|**C**urrent| | QC| | | ✓| milliamps (ex 200 = 0.2A)|

170

| 30|**RC** Mode| | |CRC| |✓|none|(((

171

CRC: Add modifier "1" for RC-position mode.

172

CRC: Add modifier "2" for RC-wheel mode.

173

Any other value for the modifier results in staying in smart mode.

174

Puts the servo into RC mode. To revert to smart mode, use the button menu.

)))

= Details =

__1. Limp (**L**)__

Example: #5L<cr>

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>.

187

188

__2. Halt & Hold (**H**)__

Example: #5H<cr>

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.

193

194

__3. Timed move (**T**)__

195

196

Example: #5P1500T2500<cr>

197

198

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.

__4. Speed (**S**)__

Example: #5P1500S750<cr>

203

204

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.

205

206

__5. (Relative) Move in Degrees (**MD**)__

Example: #5MD123<cr>

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.

211

212

__6. Origin Offset Action (**O**)__

Example: #5O2400<cr>

This command allows you to temporarily change the origin of the servo in relation to the factory zero position. The setting will be lost upon servo reset / power cycle. Origin offset commands are not cumulative and always relate to factory zero. Note that for a given session, the O command overrides the CO command. In the first image, the origin at factory offset '0' (centered).

217

218

[[image:LSS-servo-default.jpg]]

219

220

In the second image, the origina, as well as the angular range (explained below) have been shifted by 240.0 degrees:

221

222

[[image:LSS-servo-origin.jpg]]

223

224

Origin Offset Query (**QO**)

225

226

Example: #5QO<cr> Returns: *5QO-13

227

228

This allows you to query the angle (in tenths of degrees) of the origin in relation to the factory zero position.

229

230

Configure Origin Offset (**CO**)

Example: #5CO-24<cr>

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.

235

236

__7. Angular Range (**AR**)__

237

238

Example: #5AR1800<cr>

239

240

This command allows you to temporarily change the total angular range of the servo in tenths of degrees. This applies to the Position in Pulse (P) command and RC mode. The default for (P) and RC mode is 1800 (180.0 degrees total, or ±90.0 degrees). In the first image,

241

242

[[image:LSS-servo-default.jpg]]

243

244

Here, the angular range has been restricted to 180.0 degrees, or -90.0 to +90.0. The center has remained unchanged.

245

246

[[image:LSS-servo-ar.jpg]]

247

248

The angular range action command (ex. #5AR1800<cr>) and origin offset action command (ex. #5O-1200<cr>) an be used to move both the center and limit the angular range:

249

250

[[image:LSS-servo-ar-o-1.jpg]]

251

252

Query Angular Range (**QAR**)

253

254

Example: #5QAR<cr> might return *5AR2756

255

256

Configure Angular Range (**CAR**)

257

258

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.

259

260

__8. Position in Pulse (**P**)__

Example: #5P2334<cr>

The position in PWM pulses was retained in order to be backward compatible with the SSC-32 / 32U protocol. This relates the desired angle with an RC standard PWM pulse and is further explained in the SSC-32 and SSC-32U manuals found on Lynxmotion.com. Without any modifications to configuration considered, and a ±90.0 degrees standard range where 1500 microseconds is centered, a pulse of 2334 would set the servo to 165.1 degrees. Valid values for P are [500, 2500]. Values outside this range are corrected to end points.

265

266

Query Position in Pulse (**QP**)

267

268

Example: #5QP<cr> might return *5QP2334

269

270

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.

271

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).

272

273

__9. Position in Degrees (**D**)__

274

275

Example: #5PD1456<cr>

276

277

This moves the servo to an angle of 145.6 degrees, where the center (0) position is centered. Negative values (ex. -176 representing -17.6 degrees) are used. A full circle would be from -1800 to 1800 degrees. A value of 2700 would be the same angle as -900, except the servo would move in a different direction.

278

279

Larger values are permitted and allow for multi-turn functionality using the concept of virtual position.

280

281

Query Position in Degrees (**QD**)

282

283

Example: #5QD<cr> might return *5QD132<cr>

284

285

This means the servo is located at 13.2 degrees.

286

287

__10. Wheel Mode in Degrees (**WD**)__

Ex: #5WD900<cr>

This command sets the servo to wheel mode where it will rotate in the desired direction at the selected speed. The example above would have the servo rotate at 90.0 degrees per second clockwise (assuming factory default configurations).

292

293

Query Wheel Mode in Degrees (**QWD**)

294

295

Ex: #5QWD<cr> might return *5QWD900<cr>

296

297

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).

298

299

__11. Wheel Mode in RPM (**WR**)__

Ex: #5WR40<cr>

This command sets the servo to wheel mode where it will rotate in the desired direction at the selected rpm. Wheel mode (a.k.a. "continuous rotation") has the servo operate like a geared DC motor. The servo's maximum rpm cannot be set higher than its physical limit at a given voltage. The example above would have the servo rotate at 40 rpm clockwise (assuming factory default configurations).

304

305

Query Wheel Mode in RPM (**QWR**)

306

307

Ex: #5QWR<cr> might return *5QWR40<cr>

308

309

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).

310

311

__12. Speed in Degrees (**SD**)__

Ex: #5SD1800<cr>

This command sets the servo's maximum speed for action commands in tenths of degrees per second for that session. In the example above, the servo's maximum speed for that session would be set to 180.0 degrees per second. Therefore maximum speed for actions can be set "on the fly". The servo's maximum speed cannot be set higher than its physical limit at a given voltage. SD overrides CSD (described below) for that session. Upon reset or power cycle, the servo reverts to the value associated with CSD as described below. Note that SD and SR (described below) are effectively the same, but allow the user to specify the speed in either unit. The last command (either SR or SD) is what the servo uses for that session.

316

317

Query Speed in Degrees (**QSD**)

318

319

Ex: #5QSD<cr> might return *5QSD1800<cr>

320

321

By default QSD will return the current session value, which is set to the value of CSD as reset/power cycle and changed whenever a SD/SR command is processed.

322

If #5QSD1<cr> is sent, the configured maximum speed (CSD value) will be returned instead. You can also query the current speed using "2" and the current target travel speed using "3". See the table below for an example:

323

324

|**Command sent**|**Returned value (1/10 °)**

325

|ex: #5QSD<cr>|Session value for maximum speed (set by latest SD/SR command)

326

|ex: #5QSD1<cr>|Configured maximum speed (set by CSD/CSR)

327

|ex: #5QSD2<cr>|Instantaneous speed (same as QWD)

328

|ex: #5QSD3<cr>|Target travel speed

329

330

Configure Speed in Degrees (**CSD**)

Ex: #5CSD1800<cr>

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.

335

336

__13. Speed in RPM (**SR**)__

Ex: #5SD45<cr>

This command sets the servo's maximum speed for action commands in rpm for that session. In the example above, the servo's maximum speed for that session would be set to 45rpm. Therefore maximum speed for actions can be set "on the fly". The servo's maximum speed cannot be set higher than its physical limit at a given voltage. SD overrides CSD (described below) for that session. Upon reset or power cycle, the servo reverts to the value associated with CSD as described below. Note that SD (described above) and SR are effectively the same, but allow the user to specify the speed in either unit. The last command (either SR or SD) is what the servo uses for that session.

341

342

Query Speed in Degrees (**QSR**)

343

344

Ex: #5QSR<cr> might return *5QSR45<cr>

345

346

By default QSR will return the current session value, which is set to the value of CSR as reset/power cycle and changed whenever a SD/SR command is processed.

347

If #5QSR1<cr> is sent, the configured maximum speed (CSR value) will be returned instead. You can also query the current speed using "2" and the current target travel speed using "3". See the table below for an example:

348

349

|**Command sent**|**Returned value (1/10 °)**

350

|ex: #5QSR<cr>|Session value for maximum speed (set by latest SD/SR command)

351

|ex: #5QSR1<cr>|Configured maximum speed (set by CSD/CSR)

352

|ex: #5QSR2<cr>|Instantaneous speed (same as QWR)

353

|ex: #5QSR3<cr>|Target travel speed

354

355

Configure Speed in RPM (**CSR**)

Ex: #5CSR45<cr>

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.

360

361

__14. Angular Stiffness (**AS**)__

362

363

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.

364

365

A positive value of "angular stiffness":

366

367

* The more torque will be applied to try to keep the desired position against external input / changes

368

* The faster the motor will reach its intended travel speed and the motor will decelerate faster and nearer to its target position

369

370

A negative value on the other hand:

371

372

* Causes a slower acceleration to the travel speed, and a slower deceleration

373

* Allows the target position to deviate more from its position before additional torque is applied to bring it back

374

375

The default value is zero and the effect becomes extreme by -4, +4. There are no units, only integers between -4 to 4. Greater values produce increasingly erratic behavior.

Ex: #5AS-2<cr>

This reduces the angular stiffness to -2 for that session, allowing the servo to deviate more around the desired position. This can be beneficial in many situations such as impacts (legged robots) where more of a "spring" effect is desired. Upon reset, the servo will use the value stored in memory, based on the last configuration command.

Ex: #5QAS<cr>

Queries the value being used.

Ex: #5CAS<cr>

Writes the desired angular stiffness value to memory.

388

389

__15. Angular Hold Stiffness (**AH**)__

390

391

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.

Ex: #5AH3<cr>

This sets the holding stiffness for servo #5 to 3 for that session.

396

397

Query Angular Hold Stiffness (**QAH**)

398

399

Ex: #5QAH<cr> might return *5QAH3<cr>

400

401

This returns the servo's angular holding stiffness value.

402

403

Configure Angular Hold Stiffness (**CAH**)

Ex: #5CAH2<cr>

This writes the angular holding stiffness of servo #5 to 2 to EEPROM

408

409

__15b: Angular Acceleration (**AA**)__

410

411

{More details to come}

412

413

__15c: Angular Deceleration (**AD**)__

414

415

{More details to come}

416

417

__15d: Motion Control (**MC**)__

418

419

{More details to come}

420

421

__16. RGB LED (**LED**)__

Ex: #5LED3<cr>

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.

426

427

0=OFF 1=RED 2=GREEN 3= BLUE 4=YELLOW 5=CYAN 6= 7=MAGENTA, 8=WHITE

428

429

Query LED Color (**QLED**)

430

431

Ex: #5QLED<cr> might return *5QLED5<cr>

432

433

This simple query returns the indicated servo's LED color.

434

435

Configure LED Color (**CLED**)

436

437

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.

438

439

__17. Identification Number__

440

441

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.

442

443

Query Identification (**QID**)

444

445

EX: #254QID<cr> might return *QID5<cr>

446

447

When using the query ID command, it is best to only have one servo connected and thus receive only one reply using the broadcast command (ID 254). Alternatively, pushing the button upon startup and temporarily setting the servo ID to 255 will still result in the servo responding with its "real" ID.

448

449

Configure ID (**CID**)

Ex: #4CID5<cr>

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.

__18. Baud Rate__

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.

458

\*: 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.

459

460

Query Baud Rate (**QB**)

461

462

Ex: #5QB<cr> might return *5QB9600<cr>

463

464

Querying the baud rate is used simply to confirm the CB configuration command before the servo is power cycled.

465

466

Configure Baud Rate (**CB**)

Ex: #5CB9600<cr>

Sending this command will change the baud rate associated with servo ID 5 to 9600 bits per second.

471

472

__19. Gyre Rotation Direction__

473

474

"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).

475

476

{images showing before and after with AR and Origin offset}

477

478

Query Gyre Direction (**QG**)

479

480

Ex: #5QG<cr> might return *5QG-1<cr>

481

482

The value returned above means the servo is in a counter-clockwise gyration.

483

484

Configure Gyre (**CG**)

Ex: #5CG-1<cr>

This changes the gyre direction as described above and also writes to EEPROM.

489

490

__20. First / Initial Position (pulse)__

491

492

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.

493

494

Query First Position in Pulses (**QFP**)

495

496

Ex: #5QFP<cr> might return *5QFP1550<cr>

497

498

The reply above indicates that servo with ID 5 has a first position pulse of 1550 microseconds. If no first position has been set, servo will respond with DIS ("disabled").

499

500

Configure First Position in Pulses (**CFP**)

Ex: #5CP1550<cr>

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).

505

506

__21. First / Initial Position (Degrees)__

507

508

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.

509

510

Query First Position in Degrees (**QFD**)

511

512

Ex: #5QFD<cr> might return *5QFD64<cr>

513

514

The reply above indicates that servo with ID 5 has a first position pulse of 1550 microseconds.

515

516

Configure First Position in Degrees (**CFD**)

Ex: #5CD64<cr>

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.

521

522

__22. Query Target Position in Degrees (**QDT**)__

523

524

Ex: #5QDT<cr> might return *5QDT6783<cr>

525

526

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>).

527

528

__23. Query Model String (**QMS**)__

529

530

Ex: #5QMS<cr> might return *5QMSLSS-HS1cr>

531

532

This reply means the servo model is LSS-HS1, meaning a high speed servo, first revision.

533

534

__23b. Query Model (**QM**)__

535

536

Ex: #5QM<cr> might return *5QM68702699520cr>

537

538

This reply means the servo model is 0xFFF000000 or 100, meaning a high speed servo, first revision.

539

540

__24. Query Serial Number (**QN**)__

541

542

Ex: #5QN<cr> might return *5QN~_~_<cr>

543

544

The number in the response is the servo's serial number which is set and cannot be changed.

545

546

__25. Query Firmware (**QF**)__

547

548

Ex: #5QF<cr> might return *5QF11<cr>

549

550

The integer in the reply represents the firmware version with one decimal, in this example being 1.1

551

552

__26. Query Status (**Q**)__

553

554

Ex: #5Q<cr> might return *5Q6<cr>, which indicates the motor is holding a position.

555

556

|*Value returned|**Status**|**Detailed description**

557

|ex: *5Q0<cr>|Unknown|LSS is unsure

558

|ex: *5Q1<cr>|Limp|Motor driving circuit is not powered and horn can be moved freely

559

|ex: *5Q2<cr>|Free moving|Motor driving circuit is not powered and horn can be moved freely

560

|ex: *5Q3<cr>|Accelerating|Increasing speed from rest (or previous speeD) towards travel speed

561

|ex: *5Q4<cr>|Traveling|Moving at a stable speed

562

|ex: *5Q5<cr>|Deccelerating|Decreasing speed towards travel speed towards rest

563

|ex: *5Q6<cr>|Holding|Keeping current position

564

|ex: *5Q7<cr>|Stepping|Special low speed mode to maintain torque

565

|ex: *5Q8<cr>|Outside limits|More details coming soon

566

|ex: *5Q9<cr>|Stuck|Motor cannot perform request movement at current speed setting

567

|ex: *5Q10<cr>|Blocked|Similar to stuck, but the motor is at maxiumum duty and still cannot move (i.e.: stalled)

568

569

__27. Query Voltage (**QV**)__

570

571

Ex: #5QV<cr> might return *5QV11200<cr>

572

573

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).

574

575

__28. Query Temperature (**QT**)__

576

577

Ex: #5QT<cr> might return *5QT564<cr>

578

579

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.

580

581

__29. Query Current (**QC**)__

582

583

Ex: #5QC<cr> might return *5QC140<cr>

584

585

The units are in milliamps, so in the example above, the servo is consuming 140mA, or 0.14A.

586

587

__30. RC Mode (**CRC**)__

588

589

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.

590

591

|**Command sent**|**Note**

592

|ex: #5CRC<cr>|Stay in smart mode.

593

|ex: #5CRC1<cr>|Change to RC position mode.

594

|ex: #5CRC2<cr>|Change to RC continuous (wheel) mode.

595

|ex: #5CRC*<cr>|Where * is any number or value. Stay in smart mode.

EX: #5CRC<cr>

__31. RESET__

Ex: #5RESET<cr> or #5RS<cr>

602

603

This command does a "soft reset" (no power cycle required) and reverts all commands to those stored in EEPROM (i.e. configuration commands).

604

605

__32. DEFAULT & CONFIRM__

Ex: #5DEFAULT<cr>

This command sets in motion the reset all values to the default values included with the version of the firmware installed on that servo. The servo then waits for the CONFIRM command. Any other command received will cause the servo to exit the DEFAULT function.

610

611

EX: #5DEFAULT<cr> followed by #5CONFIRM<cr>

612

613

Since it it not common to have to restore all configurations, a confirmation command is needed after a firmware 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.

614

615

Note that after the CONFIRM command is sent, the servo will automatically perform a RESET.

616

617

__33. UPDATE & CONFIRM__

Ex: #5UPDATE<cr>

This command sets in motion the equivalent of a long button press when the servo is not powered in order to enter firmware update mode. This is useful should the button be broken or inaccessible. The servo then waits for the CONFIRM command. Any other command received will cause the servo to exit the UPDATE function.

622

623

EX: #5UPDATE<cr> followed by #5CONFIRM<cr>

624

625

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.

626

627

Note that after the CONFIRM command is sent, the servo will automatically perform a RESET.

628

629

=== ===

Wiki source code of LSS - Communication Protocol

Navigation