Seven-segment display

A single-digit 0.56 inch seven-segment LED display: eight plain LEDs in one package, nothing more.

The real part (a 5161AS and its many twins) is not a display controller at all. It is eight diodes sharing one internal node, brought out on two duplicate pins so the package is symmetric. There is no decoder and no multiplexing here: if you want a digit lit, you drive the segments yourself, and if you forget the series resistors the segments still light, at whatever current the probe honestly reports.

Pins

Pin	What it does
A, B, C, D, E, F, G, DP	The eight segment anodes (or cathodes, on a common-anode part).
COM1, COM2	The shared common leg, brought out twice.

Properties

common: cathode or anode. color: the LED color, which also sets the forward drop per segment.

What the model gets right

Each segment is the same diode model the LED uses, literally the same forward drop and dynamic resistance, by color. Seen from a segment leg the part is the common node plus one diode; seen from a common leg it is every lit segment in parallel. A common-cathode digit with its common grounded sinks the sum of the segment currents, exactly as it does on a real board.

What it does not model

No decoder, no BCD input, no built-in current limiting.

Each segment is the same Shockley diode the LED is, so the same caveats apply: one curve per color, no dice-to-dice variation, no junction capacitance and no temperature. The probe calls a segment lit above 1 mA, which is a threshold rather than a brightness. The bitmask is on or off per segment, so a multiplexed digit at a tenth of full current reads exactly as bright as a steady one. There is no per-segment brightness, no persistence-of-vision averaging (unlike the plain LED), no digit multiplexing and no current or power rating.

Common mistakes

Wiring a common-anode part the common-cathode way lights nothing at all, which is deliberately the mistake this part lets you make, and reading common in the properties panel is the fix. Forgetting series resistors on the segments is the other one; see the resistor.

See it in action

Electronic dice and Dice on an ESP32-C3 both drive a seven-segment digit straight from GPIO pins with resistors in series. See them at /templates.