A4988 drivers and Vref adjustment

After verifying the LCD works I went forward with electronics. I placed the heat sinks on the A4988 drivers and plugged them on the RAMPS board. Based on the instructions and markings I placed them right way and started to think about Vref adjustment. This is for the motor current and I followed the instructions on the RepRapWiki. My drivers have Rs=100 Ohm and I wanted to start safe with 0.7A so I adjusted them to have Vref of 570mV.

A4988 drives with heat sinks