How to protect long (low voltage) cables from EMI?
We can’t give exact design but principle is this.

It is critical in EMC design to understand source/load impedance and voltage or current of both signal and interference from any source over the entire spectrum from DC to RF to ensure high S/N ratio.  You can use STP or coax with &lt;100 pf/m est. with filters, and  CM chokes when necessary. 

Ferrite beads are like lossy RL similar in low pass response with RC (xx pF) but raises output Z(f), while RC lowers Zo(f) .

CM chokes do better if high CMRR (f) is needed.

Start with SNR goal then test for this.  When achieved your design is successful. Experience with all parameters above determines how to save time in choices for signal integrity, loading and compatability, EMC.

Proximity orientation and balance of actuator noise current-cable help when coupling is radiated. Quality and choice of earth ground is also significant.  Search for any keywords above for details.

If you use strong pull-up then driver must be much stronger sink. ~50-75ohms for 74HC @5V, margin is defined by attenuated noise AND DC shift. Thus trade offs. e.g SCSI uses pull-up/down for optimization.

For logic consider using Interleaved gnd ribbon cable or UTP or STP or CAT x cables and RJ style connectors


  Analog and digital grounds must be carefully selected common connection point near PS source, where currents are not shared.  When source is noisy SMPS, then CM noise can be high and reduced by raising CM impedance >1MHz with CM  choke or often best with low Z(f) earth gnd.


Keep in mind high current spikes in skinny tracks, are Inductive and high impedance // tracks have mutual coupling.