How to control multiple motors with limited pins?

I am trying to design a prosthetic hand for the lower arm for a project and I have been having a problem.

I want to use at least 6 28BYJ-48-64 unipolar stepper motors, I intend to connect these motors to a ULN2003 controller circuit each, the problem is that each motor then leaves me with four wires each need to connect to an arduino nano, which altogether has 20 (13 default, 7 analog) output pin, that would be fine, if i didn't need 5 MyoWare Muscle Sensors, each having one signal wire, so 25 pins total, 20 output, 5 input, How can I connect these sensors and motors together in a way where they are all in use simultaneously, in a way that makes the wiring compact?

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You may shall take a view here.

I'm trying to design my own for a project, not mimic someone elses.

You could use my MobaTools lib to control the steppers. At least 4 of them could be controlled by shift registers with SPI. So you need only 3 pins for this 4 motors.

Don´t you know how a learning process works, do you?


Either pick a microcontroller with may more pins, or you'll have to use some sort of I/O expander chip.

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