Cable connections

Do xl-320 engines have a front and rear face? Is it okay if the cable connections between each other are different? What are the things I should pay attention to while installing? I have a poppy sd card, how do I connect my computer to the robot via rasberry pi?

Hello @megas,

Do xl-320 engines have a front and rear face?

Yes, the side with the motor axis/horn could be considered as the “front” face. The rear has no shaft.

Is it okay if the cable connections between each other are different?

Both electrical connectors are identical, there is no importance whether you use the first or the second connector as an input or output connection.

What are the things I should pay attention to while installing?

Please read the assembly guide for the Ergo Jr.

I have a poppy sd card, how do I connect my computer to the robot via rasberry pi?

First, check if the documentation answers your question. If not, please detail your question and what you intend to do: are you asking about the cables connection, software connection, SSH/PuTTY connection…?

thanks yoan, but I have one more question. I cannot remove the cables from dc motors. What do you suggest I do?

Can you be more explicit about what you are doing? Poppy Ergo Jr has no DC motor.

I’m sorry, it’s incorrect. I meant xl-320.
Cables are a little difficult to remove from the motor. What would you recommend?

Keep them connected?
Or use a small flat screwdriver in order to push back the connector out of the socket.


" Record movement by demonstration on a Poppy Ergo Jr"
I want to write and apply the code in this video, but I am getting such errors in the notebook terminal, what should I do?

This error happens when the data received from the motors do not comply with the expected data. That may have multiple explanations. Most of the time it is just a punctual error, retry and it will be fine. But if you robot is old, the motor cables could also have been damaged, that would alter the communication: in that case they need to be replaced. This may especially apply to you since you previously mentioned that connectors were damaged.

I want the poppy ergo jr robot to record the movements of all its engines except the m2 engine. I want the m2 motor to remain stable at a 90 degree angle. The code I wrote and applied does not work. What would you suggest?

Your piece of code has some semantic errors. You should follow some tutorial about the basics of Python before using it with Poppy.

Cell 4: The second recorder variable will overwrite the first one.

Cell 5: The == operator is an equality test, that is why it returns True or False depending whether the operands are actually equal or not. It must not be confused with the affectation operator =. However the same cell with an affectation wouldn’t make sense either here, you should not affect values to poppy.tip or poppy.base, they are read-only data.

Cell 6: The and operator only applies to boolean operands. I assume that you want concatenation so that all motors from the tip or base are set compliant, in that case use + instead.

To record and replay motors, read the Move record documentation. In order to exclude m2, replace ergo.motors by the list of all motors except m2.

Finally, please keep a single topic in each Discourse thread. Your last question does not deal with the cable connections as your initial question, please open a new thread.