Is it possible to start a program on the HUB remotely?

[seecheck]

Hi, first of all I have to thank once more for the Pybricks website. I have created LEGO model of large hydraulic vibration test rig shown in the photo below. You can also watch three short videos displaying the model and its functionality here ... https://www.youtube.com/@seecheck-d5q

Motors in the model are controlled by code created using Pybricks. Currently I have one code for vertical cylinders, the other for horizontal ones. They are completely separate. Both are attached. When I want to start the model's operation, I first turn on both HUBs and then press the buttons on them simultaneously to start the program. Is there any way, please, to start the model's operation remotely using LEGO remote control or Xbox controller? Some time ago I managed to create a working code for controlling of LEGO Liebherr crane with Xbox controller. In the case of this new model I don't know what commands should be added so that the model starts working only after pressing a button on the remote control. I am sorry, I'm better at solving mechanical problems than programming. :-) Thanks in advance for any advice.
MAST_11.zip

[thomasbrus]

I first turn on both HUBs and then press the buttons on them simultaneously to start the program. Is there any way, please, to start the model's operation remotely using LEGO remote control or Xbox controller?

First hub:

data = hub.ble.observe(1)

while data is None:
    pass # Waiting until ready...

Second hub:

while not Button.A in controller.buttons.pressed():
    pass # Waiting till Button A is pressed
    
hub.ble.broadcast("rdy") # Ready signal

See https://pybricks.com/projects/tutorials/wireless/hub-to-hub/broadcast/

Something like this? (I didn't test it)

[seecheck]

Hi Thomas, thanks for reply.
Data transfering between controller and HUB or between two HUBs is not a problem. I was able to set it in my Liebherr project based on the manual and examples I found here. In that case two Technic HUBs and Xbox controller was turned on first, then program was started on HUB 1 pressing its button, after that HUB 1 was paired with the controller automatically. Finally program on HUB 2 was started by pressing its button and both HUBs were paired automatically. In this state the HUBs and motors connected to them were waiting for inputs from Xbox controller.
Situation is different in case of this new model. The code defines a sequence where the motors work simultaneously and they change speed and direction of rotation in different ways. This simulates the operation of hydraulics in a real device. I would like this entire sequence to not start immediately after pressing the buttons on the HUBs, but later, when the audience sits down, the lights in the hall go out and the button on the remote is pressed. :-) In other words, I would like the program on both HUBs to start with a pause that would be ended by pressing a button on the remote controller. Maybe it is a trivial task, but I am sorry, I have no idea how to do it.

[seecheck]

Help yourself and you will be helped. :-) New version of the code works as it was asked.
https://www.youtube.com/watch?v=FE8mfzQByqw
MAST_14.zip

[laurensvalk]

Nice work! Glad you were able to make it work.