LED displays
I2C backpack displays, SPI dot-matrix modules, bare seven-segment clocks, addressable NeoPixel grids, HUB75 RGB panels and phosphor VFDs all count as LED displays. The driver story is different for each.
Adafruit HT16K33 backpacks, MAX7219 daisy-chains, NeoPixel and DotStar grids, HUB75 RGB matrix panels, charlieplexed arrays, bare clock displays, and two VFD character modules — almost 90 parts, none wired the same way.
- Adafruit's 7-segment and 8×8 matrix backpacks drive over I2C via an HT16K33; the MAX7219 Opencircuit dot-matrix module daisy-chains over SPI-style serial; the bare 7-segment clock displays and the Matrix Clock leave the driver to you.
- NeoPixel NeoMatrix 8×8, flexible 8×32 NeoPixel and DotStar matrices are addressable-LED grids: one data line for NeoPixel, clock plus data for DotStar, with 5 V supply budgets that scale with pixel count.
- 32×32, 64×32 and 64×64 RGB matrix panels (2.5–6mm pitch, from Adafruit, DFRobot and Waveshare) use HUB75 and have no onboard controller — they need constant refresh from a capable MCU and a beefy 5 V supply.
- The 11×1 VFD Display Module and the 20×2 VFD Display (VFD29-2002I) are phosphor character displays, not LED panels; Adafruit's 9×16 charlieplexed matrices and Pimoroni's 11×7 LED Matrix Breakout are small I2C status displays at the opposite end of the complexity scale.
