Target cable with twisted pairs

Step 1:
Use separate unshielded wires to minimize capacitance and reduce crosstalk.

Step 2:
If the problem persists, add a capacitor of approximately 22 pF (acceptable range 18–27 pF) between CLOCK and GND on the nails, as close as possible to the MCU.

Step 3:
If the issue still exists, add a similar capacitor (≈22 pF) between DATA and GND on the nails.

If the issue continues, consider additional methods such as:
– Using twisted pairs
– Adding termination resistors
– Applying partial shielding
– Other EMI reduction techniques
For more details, see the document: Filter for long cables