Communicating with 2 or more ergo jr's on 1 pi

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1

Hi, I am wondering if it’s possible to communicate with 2 or more Ergo Jr’s using 1 Raspberry Pi? If so, how would this be done?
Thanks

2

I guess, I am wondering if it’s possible to communicate directly with the motors (as I am trying to communicate with 12 dynamixel XL 320’s as opposed to just the usual 6) as well.

3

Hello @B0bbi3B,

A way to do that could be to setup you own JSON robot configuration file (here is the file that describes the Ergo Junior with 6 motors), and then create a Robot object via:

robot = pypot.robot.front_json("my_2_arms.json")

In particular, using motor groups you can setup a group for the arm1 and another for the arm2. The drawbacks of doing this would be that you have to chain the motors anyway with cables, also you wouldn’t be able to use IK, but you could for instance record and replay motions or control motors from both arms independently.

4

Hey,

@B0bbi3B, you can also edit directly Ergo-Jr JSON file and use the UI with your own creature.

The best way, is to duplicate poppy_ergo_jr source and rename it with your own creature name ; rename poppy_ergo_jr.py, and rename the specific class in this file + remove primitives ; add your modification, finaly ‘bootstrap’ the robot (use bootstrap.py)… easy… :smiling_imp:

I’m working on a tuto to do this… soon … :wink:

5

Thank you everyone, Ill be giving your suggestions a try here shortly

6

Lol, I am still trying to figure this out. What do you mean by
“rename the specific class in this file + remove primitives ; add your modification, finaly ‘bootstrap’ the robot”
I’ve made the duplicate json file, but am not sure what to rename and which primitives to remove and how to run the bootstrap file

7

“remove primitives ; add your modification, finaly ‘bootstrap’ the robot”

This is where I’m currently stuck, any thoughts on which primitives to remove and how to use bootstrap? Thank you for your time

8

I think @tibo suggested to integrate your creature the the regular user interface, however that’s an advanced step. First get your JSON file working and make sure you can load it and move the motors of your 2 arms as mentioned here above, that’s maybe the hardest part.