Lynxmotion SES V2 Hexapod Robot

xan · May 17, 2021, 6:53am

Thank you for the offer @dialfonzo, I’ve found a local store that sells the headers. I hope to receive them tomorrow. I think I will be able to solve it like this.

Thanks @kurte!

cyberpalin · May 18, 2021, 9:11pm

@kurte
I started assembling you kitchen sink LSS board today - man never want to solder 805 components again :). After getting all the SMD parts on the board realized that the substitute regulator I picked up wasn’t going to work. So did a bit more of a search and found the Microchip regulator still available through Allied Electronics. According to Mouser new stock will be available January 2022! So ordered a few just in case. Looks like they my still have some BSS138s available as well. My order should be here Friday and then I can finish the board up and start playing. Do have 2 servos to test with

Do have a couple of questions though. There is a J3 3,3v jumper not sure what to do with that or what thats for. Also there is another set of jumpers on the bottom side: 10-Gnd-36, not sure what this is for. Suggestions.

Question: I saw there are a couple different versions of test legs available, if I were to get one which should it be - Open question.

kurte · May 18, 2021, 9:53pm

Good afternoon, evening: My V0.2 of the board arrived yesterday… Have not started building yet. Waiting for package from Mouser. Only differences is I changed the footprint of the Qwiic to be the vertical ones that you plug in from Top, plus I changed the VBAT stuff to be like the MicroMod where it is a rechargeable circuit…

This one?

This jumper is there when you say screw it, I don’t use that much 3.3v, especially if you are not going to use an XBee or at least a high powered XBee. You can solder jumper it and not need to populate the 3.3v VR.

Actually in my case a Via is in the middle of the text, but GND is actually SND

So for the simple sound output, you can jumper to 36 (some random PWM pin) or to pin 10 which is MSQR
Or you can do neither in which case there is another pin to the right in this picture in the 2x5 pin group which in
my case I did not move the SND label to a good place, after I moved some things around.

Note: I hear you on the 0805, although they are giants as compared to the MicroMod or Himax ribbon connector pin outs!

kurte · May 18, 2021, 9:55pm

Sorry my mind is going blank (which is not unusual )… Which test legs?

cyberpalin · May 19, 2021, 11:46am

Tell me about it. Check this link out- Lynxmotion - SES Leg Kits probably should have said kits

Oh - have another question just to confirm- the v1 board uses vertical qwic connectors correct?

kurte · May 19, 2021, 12:45pm

Good morning, maybe a better question for @dialfonzo or @cbenson - I believe those leg kits are for SES V1 robots. And I personally have not tried these new servos out on the older SES stuff. Maybe they (Robotshop) have leg kit closer to what we are playing with.

The namings of the Qwiic stuff sometimes confusing. I origionally used the Right angle pattern. Question is what does Right angle mean and in relationship to what…

But for the V1, it should be:

Which you will see that on the board not much room to then plug in the cable…

So V2 I switched the pattern to use:

So you could plug in from above.

I was hoping that they were interchangeable but found out with the boards that @dialfonzo soldered they are not… So on mine I unsoldered and put in the other one. Not sure if one could try to solder in the vertical one in backwards. You would not have pads to solder in the support.

cbenson · May 19, 2021, 12:45pm

Maybe they (Robotshop) have leg kit closer to what we are playing with.

@cyberpalin For this SES V2 Hexapod beta, the goal is really to use the Lynxmotion Smart Servos as opposed to RC servos. Although the focus is a little on the Teensy breakout at the moment because people had a stong preference for starting with a Teensy 4 as “brain”, the goal is to get the SES V2 hexapod up and walking There is currently no commercial kit, so take a look at the following:

To hold some screws in place, either idlers horns or 2-56 nuts:
2x https://www.robotshop.com/en/lynxmotion-lss-aluminum-idler-horn-set.html
1x https://www.robotshop.com/en/lynxmotion-steel-2-56-nuts-nylon-insert-lock-25.html
1x 3D printed foot
1x Rubber cover

If you plan to be an active participant in the beta, we can look into providing a bit of a discount.

cyberpalin · May 19, 2021, 1:28pm

Was afraid you were going to say that - think I will just leave them off. Too afraid if I pull the connector off it will just rip it off the board.

cyberpalin · May 19, 2021, 1:36pm

Made a wrong assumption. All the leg kits I saw showed HiTec Servo’s so assumed they would be interchangeable with the LSS Servos. Kurt’s comment that they are SESv1 explained it. Consider this a little light bulb coming on.

So would need to order the parts for the leg. Hey any discount will help so I will take you up on that offer. I am planning on helping out once I get everything set up and running, hopefully this weekend with start playing with the servos if I didn’t mess up the kitchen sink board assembly:)

cbenson · May 19, 2021, 2:12pm

Kurt’s comment that they are SESv1 explained it. Consider this a little light bulb coming on.

The approach taken when designing the Lynxmotion Smart servos was the following:

Evolution of the SES V1 system (rather than complete rework) so that everything would be recognize able, from the brackets, how everything is assembled, to the communication protocol. As you’re likely aware, the “smart” aspect behind the servos is that they are configurable and can be queried (sensor readings and more). The fact that they are meant to be daisy chained helps to clean up wiring
Keep the system “beginner friendly”: Rather than creating a highly specialized communication protocol like Robotis (well known smart servo manufacturer) used for their initial protocol, which would arguably be very difficult for beginners to learn and use, the LSS Communication protocol can be understood and implemented in a matter of minutes. This does come with some potential disadvantages though - for example no checksum was implemented, and compiling, sending and then parsing serial commands can potentially lead to issues.
Make use of the onboard sensors. For example the onboard current sensor relates to the angular resistance (i.e. torque) being applied to the driving horn, which can relates to force, like a foot hitting the ground, hence the possibility to use it for ground detection and subsequently terrain adaptation. The onboard current and temperature sensors also do their best to try to “save” the servo in the even of something going wrong, and puts the servo in an error state (which can be queried).
Multiple control modes include serial (suggested), and also RC input, so they can be used as fully configurable RC servos which take input from an RC servo controller or RC receiver.
All metal frame, all metal gears, metal horns, ball bearings, metal brackets and hardware hopefully mean an overall very rugged system.
… and more.

The goal for this BETA is to get the SES V2 Hexapod up and walking, ideally with terrain adaptation. If there are changes which are needed to the mechanics, deisgn, electronics or even the firmware loaded on the servos, this would be the time. BETA testers from the SES V2 humanoid and SES V2 quadruped are also following this thread. For example cmackenzie is banging down the door to participate so he can integrate it with ROS 2

Would you opt to start with one leg, or an entire hexapod?

cyberpalin · May 19, 2021, 2:59pm

Have very little experience with Hexapods. Most of my experience has been with autonomous rovers using all kinds of sensors for obstacle avoidance, navigation, RC/Bluetooth control for manual mode, etc. Some of my stuff is up on the PJRC forum and the OpenMV forum since I used a camera once to do the obstacle detection. Hey even did a 6-dof robotic arm, kinematics was fun (when it worked). Check my youtube channel (CyberMerln) for most of the videos :).

A whole hexapod at this time is probably a bit rich for my blood if I get all the servos needed - just the frame isn’t too bad. You do ask a very loaded question for someone like me. Could always get a frame and just load up one leg for testing and add servos as I go. Guess depends on final cost

cbenson · May 19, 2021, 6:47pm

CyberMerln - YouTube - Nice! Definitely sense a leaning towards Teensy and microcontroller performance. I’ll reach out to you directly via PM regarding how you want to get equipped for this BETA.

kurte · May 20, 2021, 1:03pm

@cbenson and @cyberpalin - would be great to have you playing as well!

Hopefully today hoping to make some more progress on the USBHost code with PS4 and clones. They all work when connected directly by cable, but need to do some have some more debugging and potentially more work on the Bluetooth code to get them all to work.

If others are wanting to play some with BT and joysticks. We have tested more on the PS3 and several of their clones.

cyberpalin · May 20, 2021, 7:38pm

@kurte
Getting back into the swing of things.

You are right something strange going on with USBHost_t36 with 1.8.15beta9. Axes were messed up and reading correctly. So I went back to 1.8.14beta8 and PS4BT is working as it should. Something happened between beta8 and beta9 that broke it. Guess we should continue this on the Teensy forum:

cyberpalin · May 22, 2021, 12:46am

Thought you all would like to see what @kurte LSS Kitchen Sink looks like when its all soldered up:

kurte · May 22, 2021, 12:53am

Looks good! My parts arrived in town today… Next few days hopefully I will be able to assemble as well.

cyberpalin · May 22, 2021, 1:46am

Now the fun begins. Only 2 things I tested was that USBHost worked and the usb/5v switch worked. Think I may have a problem with my RX LED though - its on dimly when I plug the T4.1 in

Too late to ring the board out now.

kurte · May 22, 2021, 12:24pm

Sorry, that may be semi-normal. Been a long time since I did a complete kitchen sink board that was setup for XBees.
Especially with all of the LEDS… Their usage sort of depends on if you are using an XBee or not (one plugged in) and Serial port…

Sort of a pain when not… (It is also possible I screwed that up).

But if they are working properly… They can come in handy… Sort of the last time I used a setup like this is with the DIY remote controls, that I have sort of like the one @zenta uses. Had one we adapted to XBee that was made by Jim Frye for us (old Lynxmotion days) and I also made another one…

So the LEDS came in handy.

The RSSI one let me know that the two XBees are properly paired and talking to each other.
The RX let me know that I was receiving something from the Remote (or Commander)… The TX showed when I was sending something out. With commander this did not normally ever happen. But with Remote, we would send messages back to display on screen…

Sorry in advance if I screwed up

cyberpalin · May 22, 2021, 3:09pm

@kurte

Not a problem with the RX light. I kind of like them that’s why I went to the bother of soldering them on. Besides I like XBEE’s have several of them that I use besides the 3dr radio.

Anyway I rang out the board this morning and one major things screwed up, and not even in regards to all the small components. I messed up the soldering of the GND on the connector for ext power of all things believe it or not. But all seems to work now.

According to UPS should have the leg parts on Tuesday and then will start to play in earnest. A little too tired today from all the soldering and troubleshooting. Need my nap.

cyberpalin · May 22, 2021, 10:01pm

Ok this is a real newbie question (which I am). In the library there is a setServoID command but it seems that it is only applicable to the session.

So the question is how do I permanently change the ServoID from with in the library or do I have to use the configuration tool?