OCS.ino file has...

const volatile sense_t sense[] {
  { 0, INPUT, HIGH},  // not used
  {22, INPUT, HIGH},  // Sense 1: pin#, initialize, ON state
  {24, INPUT, HIGH},  // Sense 2: pin#, initialize, ON state
  {26, INPUT, HIGH},  // Sense 3: pin#, initialize, ON state
  {28, INPUT, HIGH},  // Sense 4: pin#, initialize, ON state
  {30, INPUT, HIGH},  // Sense 5: pin#, initialize, ON state
  {32, INPUT, HIGH}   // Sense 6: pin#, initialize, ON state
};

Change the needed sense#'s to:
INPUT_PULLUP