Source: https://mokxi.com/parts/sevenseg Updated: 2026-09-27 Part # Seven segment display Common anode or cathode, with the decimal point. or see every part - 10 pins - 2 properties Drawn live by the editor's own code, at the size you see it. Reference ## Every one of its 10 pins Pin What it does E The eight segment anodes (or cathodes, on a common-anode part). D The eight segment anodes (or cathodes, on a common-anode part). COM1 The shared common leg, brought out twice. C The eight segment anodes (or cathodes, on a common-anode part). DP The eight segment anodes (or cathodes, on a common-anode part). G The eight segment anodes (or cathodes, on a common-anode part). F The eight segment anodes (or cathodes, on a common-anode part). COM2 The shared common leg, brought out twice. A The eight segment anodes (or cathodes, on a common-anode part). B The eight segment anodes (or cathodes, on a common-anode part). This part ## What it does A seven-segment display is not a smart part: it is eight ordinary LEDs in one black package, sharing one internal node that is brought out on two legs so the footprint stays symmetric. There is no decoder, no latch and no multiplexing inside it, exactly like the real thing. Each segment is the same diode model the plain LED uses, so a segment left with no series resistor still lights, at a current the probe will happily report as unrealistic rather than refusing to show it. The common leg’s polarity is the detail that catches people: a common-cathode part sinks the combined current of every lit segment through its grounded common leg, and wiring a common-anode part the common-cathode way lights nothing at all, which is precisely the mistake a real seven-segment display lets you make on a real breadboard too. Driving all eight lines from a microcontroller with pins to spare is the usual reason to reach for a 74HC595 alongside it. Reference ## The 2 properties you can set Property Default What it means common cathode (or anode) cathode or anode. color red (or green, blue, yellow, white) the LED color, which also sets the forward drop per segment. How it is modeled ## What is true about the Seven segment display, here ### What is modeled 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. ### Not modeled 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. ### LEDs, seven-segment dies and RGB LEDs (`led`) model | what sets it the same equation, with N = 2 and 12 ohm of bulk | the color's drop at 20 mA: red 1.8 V, yellow 2.0, green 3.0, blue 3.0, white 3.1 From Seven-segment display, in full. Projects ## See the Seven segment display in a project Shown here on: Arduino Uno R3, ESP32-C3-DevKitM-1 Learn ## Where it turns up in a lesson ### In a learn article - Arduino 7 Segment Display: an Electronic Die More parts ## The rest of the bench Every one of these is drawn and simulated the same way. Full-size breadboard A real 0.1 inch grid with the rails and the center channel, 63 columns wide. Jumper wires Drag from any pin or hole to any other. Corners snap, and you can drag them. Power A supply rail at the voltage you choose. Ground The other end of every circuit. LED Lights when current flows. Five colors, and the brightness is what your eye would see. Resistor Any value you like, with the color bands drawn to match. ESP32-C3-DevKitM-1 A RISC-V board that runs your firmware at 160 MHz on the real memory map. Pushbutton A 12 mm tactile switch. Hold it while the simulation runs. Raspberry Pi Pico The RP2040 board on our own Cortex-M0+ core. Pick a program and press Run. Raspberry Pi Pico W Raspberry Pi Pico W (RP2040). The same board and the same pinout as a Pico, with the CYW43439 on it. The WiFi is simulated (no radio, no real internet), and the on-board LED, which hangs off that chip rather than off GP25, is driven through the same path. Everything else is the Pico. STM32F411 Black Pill The Black Pill on our own Cortex-M4 core. Pick a program and press Run. BBC micro:bit V2 The nRF52833 board with its 5x5 LED matrix, buttons A and B and a speaker. Wire the rings to a breadboard. See every part ## Wire up the Seven segment display Open the editor and push it into the breadboard. It is free, and it runs on your own machine. Start building Open the editor