Problems with DC motors

[mister_e]

more than likely i'll use MOSFET to drive them or dedicated chip. I will use a different supply line. I mean if your motor are 5Volt, i will use a separate voltage regulator ONLY for them. Never share the PIC and logic Vdd line with the target load supply line.

Also,

1. i'll use a different ground for my PIC and for the Motors.
2. i'll tie all unused pin of the PIC to somewhere (vdd or GND)
3. i'll ensure the PIC Vdd line is correctly filtered
4. i'll screen the PIC and controller section properly to avoid incoming noise and spikes
5. maybe i'll use opto-isolator between the PIC and the motor driver. In your case.. it shouldn't be too much of problem as you don't drive a lot of current
6. i'll insert a bead on the PIC gnd line

HTH