Wiring information

[Michele]

Hello,
I am new to Poppy and I was wondering is there is any specific documentation about the wiring: I found the post with the photos of the assembly, but I have a couple of doubts it does not answer:
 - why are there two separate buses for upper and lower body? Is it a limitation of the bus (ex: speed, power, etc…) or does it have another reason?
 - how is the system powered? i.e. which motor receives the power from the SMPS2Dynamixel module?

Thanks!

Michele

[Matthieu]

Hello Michele,

@Michele

• why are there two separate buses for upper and lower body? Is it a limitation of the bus (ex: speed, power, etc…) or does it have another reason?

We separate the communication with two buses to reduce the sensorimotor loop duration.
Maybe @Pierre can give you more information on the bottlenecks and expected performance regarding the number of buses ?

@Michele

• how is the system powered? i.e. which motor receives the power from the SMPS2Dynamixel module?

The two SMPS2Dynamixel are plugged together meaning that there is only one bus for the alimentation.
This is really optional, it is just useful to plug two power supplies when we need more than 5A.

BTW thanks for your feedback about the need of documentation. I just added an associated issue on the wiki repository:

https://github.com/poppy-project/wiki/issues/6

[Pierre]

@Michele, @Matthieu

Here is just a plot of the performance depending on the number of motor on a bus. As you can see the performance basically decrease linearly with the number of motor you have on your bus. So that’s why we split poppy’s motor on two buses ^^