## Error codes
1. Voltage Low
2. Voltage High
3. Current low
4. Current high

else if (voltage_low) {
      display_error_code(1);
    } else if (voltage_high){
      display_error_code(2);
    } else if (current_low) {
      display_error_code(3);
    } else if (current_high){
      display_error_code(4);
    }