7 segment displays usually have 10 pins.Pins 3 and 8 are common - and are connected in either a common-anode (+V) orcommon-cathode (GND) configuration (you only need to connect one of them).NOTE: Seg7 works in the common-anode configuration by default. If you have a common-cathode display, you'll need to call the set_cathode() function, e.g.: display1.set_cathode(true);The rest of the pins are mapped as follows:a - 7b - 6c - 4d - 2e - 1f - 9g - 10dp/h - 5