I have a few questions about Lynxterm. Is there a manual I can reference?
On the registers page are two selections I’d like to know about: startup string and TX/Delay pacing. What are they, how are they used?
And what are the two logic states used for?
I still would like a reference doc…
Hi,
Most of the advanced features are detailed in the SSC-32U manual, starting page 36. You can read on page 36-37 the description of the registers/settings you are referring too. This section also covers the startup string.
Please note that all the features/options/menus of Lynxterm are directly related to features of the SSC-32/SSC-32U since this software is meant as the main diagnostic tool for it.
Which two logic states are you referring to?
Sincerely,
Attached screen print shows logic state 0 and logic state 1 (65535). ie constant low or constant high voltage.
Why would you use those on a servo?
another question: I have Lynxterm, Visual Sequencer, and SSC32 sequencer (Flowbotics version). There seems to be overlapping functionality. Which one should I be using to set up these initial conditions for the servos? Lynxterm has the offsets, Visual Sequencer doesn’t have a Save button (not on the sequencer page anyway), SSC32 sequencer has calibration dials, can save and run sequences.
On page 26 of the manual, it states that position offsets are NOT saved on a power cycle. You said they were written to EPROM. This explains why the values I entered had no effect.
The manual doesn’t explain the difference between initial pulse offset (-100 to 100) and initial pulse width. Where would I use one or the other? If I use pulse offset, I get a small adjustment to the servo position, whereas the pulse width gives me greater range.
The manual on page 36 indicates a value of 0 leaves the servo "at a continuous logic 0) and a value of 65535, a logic 1. I get that but elsewhere it states don’t use this on a servo!
The manual is confusing and ambiguous and imcomplete. I’ve had a Pololu servo controller (Maestro)running for 6 months with no issues. It was easy to program with their software. even the scripting part.
Hi,
The Logic State ‘0’ and Logic State ‘1’ allow you to set the initial pulse width for a servomotor either to 0 or 65535. These two values have special meaning, has seen in the description for registers 64-95 in the SSC-32U manual (page 36).
A pulse width of 0 means the SSC-32U will only output a low voltage on that pin (instead of a pulse width modulation signal) and a pulse width of 65535 means the SSC-32U will only output a high voltage on that pin. Either will cause the servo to not move (and also be “loose” instead of holding a position) since it is not receiving a pulse anymore.
Since you cannot use the slider outside of the available range, you cannot slide it to 0 or 655535, hence why there is two buttons for it.
Concerning the software, here is what they are meant for:
Lynxterm: Complete diagnostic utility including the ability to set all the different registers/advanced options of the SSC-32U easily. Also allows you to update firmware (no new one yet though).
SSC-32 Sequencer: Simple free utility to give the ability to create sequences with the SSC-32U.
Visual Sequencer: Legacy software (now discontinued) with limited support. Not recommended for new projects.
For most simple projects, the free sequencer utility should be enough. If you need more features, you can always get FlowBotics Studio and modify it / add features as needed directly.
Sincerely,
The details on page 26 mentions that the PO command changes the offset of the signal position sent to servomotors. This offset is not saved on power off.
The initial pulse offset (as described on page 36) is set in the registers. Basically, on power-up, the SSC-32U will effectively send itself 32 “PO” commands for those values, therefore saving your offset (usually used for calibration with robots).
The initial pulse width is the initial position you wish your servomotor to be at, usually 1000-2000 ms, some motors support a range up-to 500-2500 ms.
Sometimes when building complex robots, the brackets and such will have an offset and it makes position 1500 (default RC center position) not look centered with the bracket on. This is where you use the initial pulse offset setting to change where the center will land (-100 to +100) so that everything is aligned on power-up (calibration).
Sincerely,
I was wondering WHY one would put the servo at those values. Just to “shut them off?”
I may have found a problem I’ve been blaming on software and hardware (ssc32). I noticed that SOME of my servos would go wonky whenever I cycled power, some did not. Even if I used the same pin output with same values, one servo would move, the other would not (as I expected). It appears that not all servos are created equal…in fact many of the servos I’m using are knock-offs of Tower Pro. (They are named “TowardPro” a sure give away. You get what you pay for I guess!!
So rather than chase my tail with the ssc32 and the software supplied, I’ll concentrate on servos that don’t move when power cycled.
This is driving me nuts.
I put three fake TowerPro servos on ports 16,17,18 and three real servos (MG996R) on ports 0,1,2. Power is from 7.2 v lipo battery or 6.0 volt power supply. I tried both same result.
When I power down then power up, the servos wind up a bit, ie move in one direction 5-10 deg. If I power cycle again, they move in the same direction another 5-10 degrees. That’s right the fake servos and the real servos do the SAME THING. When all connected to the 17 on the biped, they twist every which way, like a crash-test dummy!
In the SSC32 sequencer I put all 6 in a group set at some value, way off 1500 uS, like around 1000 uS. I SAVE the servo setup. I power cycle get the movement I just mentioned. The sequencer still shows the same values (as it should because I don’t shut it down). I move the servos back to center, then LOAD my servo setup where they were set at 1000uS. There is NO CHANGE.
I’m doing this all on the bench with 6 loose servos, bench power supply or battery, and I have two different ssc32 boards to experiment with. Both give same results.
This is what I have been chasing since I put all this together. I blamed software, ssc32, and servos, but they all exhibit the same symptoms.
Bottom line: I can’t save servo configurations and my servos move when powered up. Any clues here? I decoupled my power supply at the power input with a cap but made no difference.
Hi all,
I have a similar question: what is the difference between Offset and Width and which one should I use for calibration. For some servos the offset range is not enough to move to the inititial Position, but using the Width slider works , so what is the right way ?
Many thanks in advance 
Hi,
In the future, please refrain from reviving and older thread. Instead, create a new topic and link to the thread of interest, as this makes it easier to provide support (1 topic = 1 problem). This is mostly because while many problems/questions may look the same, they can quickly diverge and therefore make it confusing for future readers.
As for your question, please see the post above:
Sincerely,
