Is it possible to program hub to hub communication easier?

[Flippoel]

Hi,
We are working on a quite complicated program. We try to operate a model, with 8 technic hubs, by a self build remote. The self build remote is made from a Spike Prime hub together with a Xbox controller.

So far we programmed the Spike prime hub partially, and two technic hubs.

To get is working, we need to program all values in every hub in the right order while we only need a few values per technic hub.
So every time we program a new function we need to put the value in every hub and unpack it before if works.
If not we constantly get the error: 'to many values to unpack'

Is there a way to do this easier?
PS, we only work with the block coding

[laurensvalk]

How about using a long list everywhere, and just use only the values that you need? The you don't need to update any listing hubs when you add a new function.

[Flippoel]

Hi Laurens,
You mean a long list on forehand? and then pick one if we program the next function? That can make this easier, but that doesn't change the way we program now.
Is it richt that every hub needs to unpack the whole list? Is there not a way to let a specific hub only unpack that what it needs?

Thanks for your help.

[laurensvalk]

If each hub just unpacks the maximum number of variables, even if you don't use all of the values, you shouldn't have to change them anymore, right?

Is it richt that every hub needs to unpack the whole list? Is there not a way to let a specific hub only unpack that what it needs?

You have more flexibility with Python, but the above suggestion should make it easy for blocks, too:

So if your list is always the same size everywhere, you can leave it up to the program specifics to change what you use.

[Flippoel]

Thank Laurens, I think the most simple solution for us at this moment, is to make a list of functions and put that in one hub and then copy is to the others.

[Flippoel]

I'm sorry, but here we are again. I tried to make a list of 35 values, but I get this error now when I try to upload it to the Spike prime hub: 'ValueError: payload limited to 26 bytes'
Does that mean that we can send maximum 26 values?

[dlech]

Actually, less than that because there is some overhead to encode the type and size of the value which is 1 extra byte per value.

To pack the maximum amount of info (bits) in a message, you can send one value that is a bytes object that is 25 bytes long.

Sending info as individual objects could fit up to 13 values, and would require each value to be small enough to encode in 1 byte.

[laurensvalk]

Can we turn the problem around? 🙂

How many values would you like to send? I think last time we arrived at a working option.