LSS - Firmware

Last modified by Eric Nantel on 2021/09/20 14:55

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Firmware Versions

This section contains details about official firmware releases for the the Lynxmotion Smart Servos (LSS). Information includes release date (yyyy-mm-dd), and which new features / fixes / etc. were included. It also provides and any details about known issues or other warnings. If you are unsure how to proceed to update your LSS, please see this guide.

Version 367

Released 2019-10-07

  • Fixes:
    • Minor improvements to handling of low-speed motion control. More updates coming soon on this front!
    • Encoder issue that would sometimes cause random fast motion, ignoring speed restrictions.

Version 365

Released 2019-09-12

  • New commands:
    • New modifiers for position commands CH & CL. Allows moving "into" an object so it can be held without going into safe mode (limiting applied current in mA). CH holds position on collision and CL goes limp instead.
  • Fixes:
    • Mode 255 would sometimes stay active or cause the LSS to respond to other servo IDs

Version 362

Released 2019-05-01

Initial production version (first official release)

  • New commands:
    • CLB/QLB to control the blinking of the RGB LED during various phases of motion.
  • New features:
    • Added failsafe to go from RC mode back to serial mode by placing a HIGH signal (5 V DC) on RX for 30 s.
  • Fixes:
    • Improved LED patterns for clarity.
    • ID is now kept during a firmware update.

Version 368

Released 2020-04-07

Many bug fixers and new features!

  • New features: 
    • QF now reports more details on version number (QF, QF1, QF2, QF3)
    • Maximum motor duty cycle can be controlled using MMD, QMMD (min25%, max100% = 1023).
      • Can set it asymmetrical by passing 2 values separated by a comma (pos limit, neg limit).
    • Motion filter was added for EM0.
      • Can be controlled with FPC, CFPC, QFPC.
    • IPMS system was added for EM0.
      • Controlled with IPE and QIPE

Version 369 (EXPERIMENTAL)

Released 2021-06-18

  • New features 
    • Support for baud rates higher than 250k. Certified 9600, 19200, 38400, 57600, 230400, 250000, 460800 and 500000 baud but 750000 and 921600 have also passed our testing. Only these exact baud rates are recognized by the servo. 
    • Improvement in query response time of around 15% at 250k baud and much greater now that higher baud rates can be used.
  • Fixes
    • Fixed race condition in communication resulting in occasional corrupt responses. Most prevelant but not limited to the QN command. 

Version 370 (EXPERIMENTAL)

Released 2021-09-20

Major overhaul to the communication sub-system. Expect major performance improvements and bugs! Backwards compatibility is a priority. This firmware shouldn't affect existing code, please report any issues and include a reproductible command sequence if possible.

  • New features
    • Group commands: Allows multiple commands to be sent and received as a group and can include multiple servos without bus conflict / contention
      • #0QD#5QD#10QD\r        -   As an example, this single command queries three servos for their respective positions
      • #0QD0QC0#5QD0QC0   -   This queries two servos for their position and current (milliamps). Note: 0 is required to separate commands QD and QC
    • Auto Baud Rate (ABR) which can be enabled (off by default):
      • #254ABR1                  -   Enable baud rate detection on first byte received after power-up.
      • #254ABR2,30             -   Enable baud rate detection on first byte received after power-up. If no data for 30 seconds enable detection again on next byte.
      • Warning: ABR doesn't work well with LSS Config at the moment
    • Delayed & ordered query response.
      • #254QID120               -   For example, this command can scan the entire bus at once for servos without conflict.
      • Servos use a simple formula to delay their response: 200usec + <id> * 120usec, where <id> is their servo ID 0 to 253.
      • The first parameter (ex. 120) indicates how many milliseconds to delay between IDs and 120usec is a safe number.
      • Warning: #254QID with no parameter will still conflict to remain backward compatible with the LSS Config software
    • Configure a SLOT # for each servo and using (ex.)
      • #254QD                        -    An example of how all servos can be queried at once without conflict
      • Ex. Three servos with ID 0, 5, and 10 and want to configure them to be slots 0, 1, and 2 respectively:
        • #254SLOTCOUNT3\r  - configures 3 slots on the bus
        • #0SLOT0\r          -   Don't really have to do this one, servos default to slot 0 on power-up
        • #5SLOT1\r          -   Servo ID5 to slot 1
        • #10SLOT2\r        -   Servo ID10 to slot 2
        • #254QD\r            -   Query all servos for position
        • #254QD0QC0\r   -   Query all servos for position and current (milliamps)
      • Note: You only need to configure slots once on power-up, #254<cmd> will offset all servo replies based on slot# after this is set.
      • Note: Why not just use servo ID as slot#? Many LSS bus setups are not using sequential IDs so it's more efficient to assign slot# then expect everyone to change their robot's logical servo IDs to be sequential.
  • Fixes
    • Increase in supported baud rates up to 921k (adds 500k, 750k, 921.6k)
    • Fixed memory leak in MMD command
    • General firmware cleanup & improvements
Created by RB1 on 2019/11/22 11:29
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