Display Digital

LED Bar Graph

An LED bar graph is a row of individual LEDs in one package, useful for showing levels such as progress, volume, signal strength, or sensor value.

Part images

LED bar graph. A row of LEDs in one display package. Image source: SunFounder Pico 2 W Starter Kit documentation, Components section, © 2026 SunFounder.
LED bar pin reference. Pin side reference from SunFounder. Image source: SunFounder Pico 2 W Starter Kit documentation, Components section, © 2026 SunFounder.
LED bar schematic. Internal LED segment schematic. Image source: SunFounder Pico 2 W Starter Kit documentation, Components section, © 2026 SunFounder.

What it is

An LED bar graph is a row of individual LEDs in one package, useful for showing levels such as progress, volume, signal strength, or sensor value.

How students use it

Students drive it like ten separate LEDs, often with one resistor per segment and either direct GPIO or an output-expander/shift-register circuit.

Pins and power

The bar graph exposes one anode/cathode pair per LED segment. SunFounder notes the labeled side typically represents the anode and the opposite side the cathode.

Each LED segment needs current limiting. Current planning matters if many segments are on at once.

Check the SunFounder pin and schematic images before wiring; treat each bar as a separate LED.

Voltage and safety

The display package does not include current limiting. Use resistors and stay within current limits.

Turning all segments on can draw much more current than one LED.

Module internals

Ten LED dies in one package; each segment behaves like a separate LED.

Datasheet notes

SunFounder does not identify a specific bar graph manufacturer part number. Match the package markings before using a datasheet.

Common libraries

No special library is needed; use machine.Pin or drive through a 74HC595 when lessons need fewer Pico GPIO pins.

Common mistakes

Skipping resistors, wiring the labeled side backward, assuming one common pin controls the whole display, and exceeding current limits when all bars are lit.