Last modified by Eric Nantel on 2025/06/06 07:47
From version < 94.1 >
edited by Coleman Benson
on 2019/02/01 12:00
To version < 93.1 >
edited by Coleman Benson
on 2019/01/31 15:51
< >
Change comment: There is no comment for this version

Summary

Details

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Content
... ... @@ -5,9 +5,9 @@
5 5  
6 6  = Serial Protocol Concept =
7 7  
8 -The custom Lynxmotion Smart Servo (LSS) serial protocol was created in order to be as simple and straightforward as possible from a user perspective ("human readable format"), while at the same time compact and robust yet highly versatile. The protocol was based on Lynxmotion's SSC-32 RC servo controller and almost everything one might expect to be able to configure for a smart servo motor is available.
8 +The Lynxmotion Smart Servo (LSS) serial protocol was created in order to be as simple and straightforward as possible from a user perspective ("human readable"), while at the same time trying to be compact and robust yet highly versatile. The protocol was based on Lynxmotion's SSC-32 RC servo controller and almost everything one might expect to be able to configure for a smart servo motor is available.
9 9  
10 -In order to have servos react differently when commands are sent to all servos in a serial bus, the first step a user should take is to assign a different ID number to each servo (explained below). Once this has been done, only the servo(s) which have been assigned to the ID sent as part of the command will follow that command. There is currently no CRC / checksum implemented as part of the protocol.
10 +In serial mode, in order to have servos react differently when commands are sent to all servos in a bus, the first step a user should take is to assign a different ID number to each servo (explained below). Once this has been done, only the servo(s) which have been assigned to the ID sent as part of the command will take action. There is currently no CRC / checksum implemented as part of the protocol.
11 11  
12 12  == Session ==
13 13  
... ... @@ -15,7 +15,7 @@
15 15  
16 16  == Action Commands ==
17 17  
18 -Action commands tell the servo, within that session, to do something (i.e. "take an action"). The types of action commands which can be sent are described below, and they cannot be combined with other commands such as queries or configurations. Only one action command can be sent at a time. Action commands are session-specific, therefore once a servo is power cycled, it will not have any "memory" of previous actions or virtual positions (described below on this page). Action commands are sent serially to the servo's Rx pin and must be sent in the following format:
18 +Action commands tell the servo, within that session, to do something (i.e. "take an action"). The type of action commands which can be sent are described below, and they cannot be combined with other commands such as queries or configurations. Only one action command can be sent at a time. 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). Action commands are sent serially to the servo's Rx pin and must be set in the following format:
19 19  
20 20  1. Start with a number sign # (U+0023)
21 21  1. Servo ID number as an integer
... ... @@ -26,11 +26,11 @@
26 26  (((
27 27  Ex: #5PD1443<cr>
28 28  
29 -This sends a serial command to all servo's Rx pins which are connected to the bus and only servo(s) with ID #5 will move to a position in tenths of degrees ("PD") of 144.3 degrees. Any servo on the bus which does not have ID 5 will take no action when receiving this command.
29 +This sends a serial command to all servo's Rx pins which are connected to the bus and only servo(s) with ID #5 will move to a position of 144.3 degrees. Any servo in the bus which does not have ID 5 will take no action when they receive this command.
30 30  
31 31  == Action Modifiers ==
32 32  
33 -Only two commands can be used as action modifiers: Timed Move (T) and Speed (S) described below. Action modifiers can only be used with certain action commands. The format to include a modifier is:
33 +Only two commands can be used as action modifiers: Timed Move (T) and Speed (S). Action modifiers can only be used with certain action commands. The format to include a modifier is:
34 34  
35 35  1. Start with a number sign # (U+0023)
36 36  1. Servo ID number as an integer
... ... @@ -42,12 +42,12 @@
42 42  
43 43  Ex: #5P1456T1263<cr>
44 44  
45 -This results in the servo with ID #5 rotating from the current angular position to a pulse position ("P") of 1456 in a time ("T") of 1263 milliseconds.
45 +This results in the servo with ID #5 rotating from the current angular position to a pulse position of 1456 in 1263 milliseconds. Position in pulses is described below.
46 46  )))
47 47  
48 48  == Configuration Commands ==
49 49  
50 -Configuration commands and corresponding values affect a servo's defaults which are written to and read from the servo's EEPROM. These configurations are retained in memory after the servo is reset or power is cut / lost. Some configuration commands affect the session, while others do not (see each command for details). Not all action commands have a corresponding configuration and vice versa. More information about which configuration commands are retained when in RC mode can be found on the [[LSS - RC PWM page>>doc:Lynxmotion Smart Servo (LSS).LSS - RC PWM.WebHome]]. Configuration commands are not cumulative, in that if two configurations are sent, one after the next, only the last configuration is used and stored. The format to send a configuration command is identical to that of an action command:
50 +Configuration commands affect a servo's default values which are written to the servo's EEPROM and are retained in memory after the servo loses power or is reset. Some configuration commands affect the session, while others do not (see each command for details). Not all action commands have a corresponding configuration and vice versa. More information about which configuration commands are retained in RC mode can be found on the [[LSS - RC PWM page>>doc:Lynxmotion Smart Servo (LSS).LSS - RC PWM.WebHome]]. Configuration commands are not cumulative, in that if two configurations are sent, one after the next, only the last configuration is used and stored. The format to send a configuration command is identical to that of an action command:
51 51  
52 52  1. Start with a number sign # (U+0023)
53 53  1. Servo ID number as an integer
... ... @@ -57,11 +57,11 @@
57 57  
58 58  Ex: #5CO-50<cr>
59 59  
60 -This configures an absolute origin offset ("CO") with respect to factory origin to servo with ID #5 and changes the offset for that session to -5.0 degrees (50 tenths of degrees). Once the servo is powered off and then powered on, zeroing the servo will cause it to move to -5.0 degrees with respect to the factory origin and report its position as 0 degrees. Configuration commands can be undone / reset either by sending the servo's default value for that configuration, or by doing a factory reset (clears all configurations) described below.
60 +This assigns an absolute origin offset of -5.0 degrees (with respect to factory origin) to servo with ID #5 and changes the offset for that session to -5.0 degrees. Once the servo is powered off and then powered on, zeroing the servo will cause it to move to -5.0 degrees with respect to the factory origin. Configuration commands can be undone / reset either by sending the servo's default value for that configuration, or by doing a factory reset (clears all configurations) described below.
61 61  
62 62  == Query Commands ==
63 63  
64 -Query commands request information from the servo. They are received via the Rx pin of the servo, and the servo's reply is sent via the servo's Tx pin. Using separate lines for Tx and Rx is called "full duplex". Query commands are also similar to action and configuration commands and must use the following format:
64 +Query commands request information from the servo. They are received via the Rx pin of the servo, and the servo's reply is sent via the servo's Tx pin. This is called "full duplex". Query commands are also similar to action and configuration commands and must use the following format:
65 65  
66 66  1. Start with a number sign # (U+0023)
67 67  1. Servo ID number as an integer
... ... @@ -81,39 +81,41 @@
81 81  1. The reported value in the units described, no decimals.
82 82  1. End with a control / carriage return '<cr>'
83 83  
84 -There is currently no option to control how fast a servo replies after it has received a query command, therefore when sending a query command to the bus, the controller should be prepared to immediately "listen" for and parse the reply. Sending multiple queries on a bus in fast succession may result in replies overlapping and giving incorrect or corrupt data. As such, the controller should receive a reply before sending a new command. A reply to the query sent above might be:
84 +There is currently no option to control how fast a servo replies after it has received a query command, therefore when sending a query command to the bus, the controller should be prepared to immediately "listen" for and parse the reply. Sending multiple queries on a bus in fast succession may result in replies overlapping and giving incorrect or corrupt data. As such, the controller should receive a reply before sending a new command.
85 85  
86 86  (((
87 87  Ex: *5QD1443<cr>
88 88  )))
89 89  
90 -This indicates that servo #5 is currently at 144.3 degrees (1443 tenths of degrees).
90 +This reply to the query above indicates that servo #5 is currently at 144.3 degrees (1443 tenths of degrees).
91 91  
92 92  **Session vs Configuration Query**
93 93  
94 -By default, the query command returns the sessions' value. Should no action commands have been sent to change the session value, it will return the value saved in EEPROM which will either be the servo's default, or modified with a configuration command. In order to query the value stored in EEPROM (configuration), add a '1' to the query command:
94 +By default, the query command returns the sessions' value. Should no action commands have been sent to change the session value, it will return the value saved in EEPROM from the last configuration command.
95 95  
96 -Ex: #5CSR20<cr> immediately sets the maximum speed for servo #5 to 20rpm (explained below) and changes the value in memory.
96 +In order to query the value in EEPROM (configuration), add a '1' to the query command.
97 97  
98 -After RESET, a command of #5SR4<cr> sets the session's speed to 4rpm, but does not change the configuration value in memory. Therefore:
98 +Ex: #5CSR20<cr> immediately sets the maximum speed for servo #5 to 20rpm (explained below) .
99 99  
100 -#5QSR<cr> would return *5QSR4<cr> which represents the value for that session, whereas
100 +After RESET: #5SR4<cr> sets the session's speed to 4rpm.
101 101  
102 +#5QSR<cr> would return *5QSR4<cr> which represents the value for that session.
103 +
102 102  #5QSR1<cr> would return *5QSR20<cr> which represents the value in EEPROM
103 103  
104 104  == Virtual Angular Position ==
105 105  
106 -The ability to store a "virtual angular position" is a feature which allows for rotation beyond 360 degrees, permitting multiple rotations of the output horn, moving the center position and more. In virtual position mode, the "absolute position" would be the angle of the output shaft with respect to a 360.0 degree circle, and can be obtained by taking the modulus (with respect to 360 degrees) of the value. For example if the virtual position is reported as 15335 (or 1533.5 degrees), taking the modulus would give 93.5 degrees (3600 * 4 + 935 = 15335) as the absolute position (assuming no origin offset).
108 +A "virtual position" is a feature which allows for rotation beyond 360 degrees, permitting multiple rotations of the output horn, moving the center position and more. In virtual position mode, the "absolute position" would be the angle of the output shaft with respect to 360.0 degrees, and can be obtained by taking the modulus (with respect to 360 degrees) of the value. For example if the virtual position is reported as 15335 (or 1533.5 degrees), taking the modulus would give 93.5 degrees (3600 * 4 + 935 = 15335).
107 107  
108 108  [[image:LSS-servo-positions.jpg]]
109 109  
110 -In this example, the gyre direction (explained below, a.k.a. "rotation direction") is positive (clockwise), and origin offset has not been modified. Each square represents 30 degrees. The following command is sent:
112 +In this example, the gyre direction (explained below, a.k.a. rotation direction) is positive (clockwise), and origin offset has not been modified. Each square represents 30 degrees. The following command is sent:
111 111  
112 112  #1D-300<cr> This causes the servo to move to -30.0 degrees (green arrow)
113 113  
114 114  #1D2100<cr> This second position command is sent to the servo, which moves it to 210.0 degrees (orange arrow)
115 115  
116 -#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 plus 60.0 degrees (420.0 - 360.0), with a virtual position of -420.0 degrees.
118 +#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.
117 117  
118 118  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.
119 119  
... ... @@ -131,37 +131,29 @@
131 131  | 2|[[**H**alt & **H**old>>||anchor="H2.Halt26Hold28H29"]]| H| | | | ✓|none|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
132 132  | 3|[[**T**imed move>>||anchor="H3.Timedmove28T29"]]| T| | | | ✓|milliseconds|(% style="width:510px" %) Modifier only for {P, D, MD}|(% style="text-align:center; width:113px" %)
133 133  | 4|[[**S**peed>>||anchor="H4.Speed28S29"]]| S| | | | ✓|microseconds / second|(% style="width:510px" %) Modifier only {P}|(% style="text-align:center; width:113px" %)
134 -| 5|[[**M**ove in **D**egrees (relative)>>||anchor="H5.28Relative29MoveinDegrees28MD29"]]| MD| | | | ✓|tenths of degrees (ex 325 = 32.5 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
135 -| 6|[[**O**rigin Offset>>||anchor="H6.OriginOffsetAction28O29"]]| O| QO| CO| ✓| ✓|tenths of degrees (ex 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)(((
136 +| 5|[[**M**ove in **D**egrees (relative)>>||anchor="H5.28Relative29MoveinDegrees28MD29"]]| MD| | | | ✓|tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
137 +| 6|[[**O**rigin Offset>>||anchor="H6.OriginOffsetAction28O29"]]| O| QO| CO| ✓| ✓|tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)(((
136 136  0
137 137  )))
138 -| 7|[[**A**ngular **R**ange>>||anchor="H7.AngularRange28AR29"]]| AR| QAR| CAR| ✓| ✓|tenths of degrees |(% style="width:510px" %) |(% style="text-align:center; width:113px" %)(((
140 +| 7|[[**A**ngular **R**ange>>||anchor="H7.AngularRange28AR29"]]| AR| QAR| CAR| ✓| ✓|tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)(((
139 139  1800
140 140  )))
141 141  | 8|[[Position in **P**ulse>>||anchor="H8.PositioninPulse28P29"]]| P| QP| | | ✓|microseconds|(% style="width:510px" %)(((
142 142  Inherited from SSC-32 serial protocol
143 143  )))|(% style="text-align:center; width:113px" %)
144 -| 9|[[Position in **D**egrees>>||anchor="H9.PositioninDegrees28D29"]]| D| QD| | | ✓|tenths of degrees |(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
146 +| 9|[[Position in **D**egrees>>||anchor="H9.PositioninDegrees28D29"]]| D| QD| | | ✓|tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
145 145  | 10|[[**W**heel mode in **D**egrees>>||anchor="H10.WheelModeinDegrees28WD29"]]| WD| QWD| | | ✓|tenths of degrees per second (ex 248 = 24.8 degrees per second)|(% style="width:510px" %)A.K.A. "Speed mode" or "Continuous rotation"|(% style="text-align:center; width:113px" %)
146 146  | 11|[[**W**heel mode in **R**PM>>||anchor="H11.WheelModeinRPM28WR29"]]| WR| QWR| | | ✓| rpm|(% style="width:510px" %)A.K.A. "Speed mode" or "Continuous rotation"|(% style="text-align:center; width:113px" %)
147 -| 12|[[Max **S**peed in **D**egrees>>||anchor="H12.SpeedinDegrees28SD29"]]| SD| QSD|CSD| ✓| ✓|tenths of degrees per second |(% style="width:510px" %)(((
148 -QSD: Add modifier "2" for instantaneous speed.
149 -
150 -SD overwrites SR / CSD overwrites CSR and vice-versa.
151 -)))|(% style="text-align:center; width:113px" %)Max per servo
152 -| 13|[[Max **S**peed in **R**PM>>||anchor="H13.SpeedinRPM28SR29"]]| SR| QSR|CSR| ✓| ✓|rpm|(% style="width:510px" %)(((
153 -QSR: Add modifier "2" for instantaneous speed
154 -
155 -SR overwrites SD / CSR overwrites CSD and vice-versa.
156 -)))|(% style="text-align:center; width:113px" %)Max per servo
149 +| 12|[[Max **S**peed in **D**egrees>>||anchor="H12.SpeedinDegrees28SD29"]]| SD| QSD|CSD| ✓| ✓|tenths of degrees per second (ex 248 = 24.8 degrees per second)|(% style="width:510px" %)QSD: Add modifier "2" for instantaneous speed|(% style="text-align:center; width:113px" %)Max per servo
150 +| 13|[[Max **S**peed in **R**PM>>||anchor="H13.SpeedinRPM28SR29"]]| SR| QSR|CSR| ✓| ✓|rpm|(% style="width:510px" %)QSR: Add modifier "2" for instantaneous speed|(% style="text-align:center; width:113px" %)Max per servo
157 157  | 16|[[**LED** Color>>||anchor="H16.RGBLED28LED29"]]| LED| QLED| CLED| ✓| ✓|none (integer from 0 to 8)|(% style="width:510px" %)0=Off (black); 1=Red 2=Green; 3=Blue; 4=Yellow; 5=Cyan; 6=Magenta; 7=White;|(% style="text-align:center; width:113px" %)7
158 158  | 17|[[**ID** #>>||anchor="H17.IdentificationNumber"]]| | QID| CID| | ✓|none (integer from 0 to 250)|(% style="width:510px" %)Note: ID 254 is a "broadcast" which all servos respond to|(% style="text-align:center; width:113px" %)0
159 159  | 18|[[**B**aud rate>>||anchor="H18.BaudRate"]]| B| QB| CB| | ✓|none (integer)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)9600
160 -| 19|[[**G**yre direction (**G**)>>||anchor="H19.GyreRotationDirection"]]| G| QG| CG| ✓| ✓|none |(% style="width:510px" %)Gyre / rotation direction where 1= CW (clockwise) -1 = CCW (counter-clockwise)|(% style="text-align:center; width:113px" %)1
161 -| 20|[[**F**irst Position (**P**ulse)>>||anchor="H20.First2InitialPosition28pulse29"]]| | QFP|CFP | ✓| ✓|none |(% style="width:510px" %)CFP overwrites CFD and vice-versa|(% style="text-align:center; width:113px" %)(((
154 +| 19|[[**G**yre direction (**G**)>>||anchor="H19.GyreRotationDirection"]]| G| QG| CG| ✓| ✓|none |(% style="width:510px" %) Gyre / rotation direction where 1= CW (clockwise) -1 = CCW (counter-clockwise)|(% style="text-align:center; width:113px" %)1 CW
155 +| 20|[[**F**irst Position (**P**ulse)>>||anchor="H20.First2InitialPosition28pulse29"]]| | QFP|CFP | ✓| ✓|none |(% style="width:510px" %) |(% style="text-align:center; width:113px" %)(((
162 162  Limp
163 163  )))
164 -| 21|[[**F**irst Position (**D**egrees)>>||anchor="H21.First2InitialPosition28Degrees29"]]| | QFD|CFD| ✓| ✓|none |(% style="width:510px" %)CFD overwrites CFP and vice-versa|(% style="text-align:center; width:113px" %)Limp
158 +| 21|[[**F**irst Position (**D**egrees)>>||anchor="H21.First2InitialPosition28Degrees29"]]| | QFD|CFD| ✓| ✓|none |(% style="width:510px" %) |(% style="text-align:center; width:113px" %)Limp
165 165  | 22|[[**T**arget (**D**egree) **P**osition>>||anchor="H22.QueryTargetPositioninDegrees28QDT29"]]| | QDT| | | ✓|tenths of degrees (ex 325 = 32.5 degrees; 91 = 9.1 degrees)|(% style="width:510px" %) |(% style="text-align:center; width:113px" %)
166 166  | 23|[[**M**odel **S**tring>>||anchor="H23.QueryModelString28QMS29"]]| | QMS| | | |none (string)|(% style="width:510px" %) Recommended to determine the model|(% style="text-align:center; width:113px" %)
167 167  | 23b|[[**M**odel>>||anchor="H23b.QueryModel28QM29"]]| | QM| | | |none (integer)|(% style="width:510px" %) Returns a raw value representing the three model inputs (36 bit)|(% style="text-align:center; width:113px" %)
... ... @@ -181,6 +181,7 @@
181 181  |32|[[**DEFAULT**>>||anchor="H32.DEFAULTA026CONFIRM"]]| | | | |✓|none|(% style="width:510px" %)Revert to firmware default values. See command for details|(% style="text-align:center; width:113px" %)
182 182  |33|[[**UPDATE**>>||anchor="H33.UPDATEA026CONFIRM"]]| | | | |✓|none|(% style="width:510px" %)Update firmware. See command for details.|(% style="text-align:center; width:113px" %)
183 183  
178 +(% class="wikigeneratedid" %)
184 184  == Advanced ==
185 185  
186 186  |= #|=Description|= Action|= Query|= Config|= RC|= Serial|= Units|=(% style="width: 510px;" %) Notes|=(% style="width: 113px;" %)Default Value

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