How to connect 2 vex Iq brains together

[Guu_da_singh]

I am making a robot with a 12 wheel drive, we are using two brains, 6 moteres on one brain, 6 on the other brain, we want to link the two brains together, so we only need to use one controller for both of them.

[Rivaan]

Correct me if I’m wrong but don’t VEX IQ brains have 12 smart ports that you could connect motors to?

[Nosypoke]

You’re correct.

[jpearman]

That would need code running on both IQ Generation 2 brains and a special cable to connect them, see some details in this topic.

How to connect one or more VIQ brains to each other

Here’s a very simple demo using two IQ2 brains. crossover cable (swap scl/sda) with gnd is needed, disconnect power and the other signals. One sends (well, technically they both send in this demo) the string “Hello” the other is receiving it. [IMG_1759] Here is the C++ code, in practice for reliable communication you need to invent a suitable protocol handling partial reception of data, error checking etc.

C++ demo code

/*---------------------------------------------------------------------…

@Rivaan

12 smart ports that you could connect motors to

Then there’s no room for other sensors. 12 motors spilt across two batteries will also work a little better.

[Guu_da_singh]

I already made a crossover cable, the brains turned on simultaneously, but they didn’t communicate with each other. My partner and I want to use one controller to control all the wheels, a touch LED, and a claw.

[jpearman]

@Guu_da_singh

but they didn’t communicate with each other.

You have to create a program (and suitable protocol) on both brains to allow communication.

[Guu_da_singh]

how do I do that, Im done with the project, but still want to know how to do it.