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How to control LEDs connected to FAST Expansion Boards

Understanding EXP board addressing

This command is used with FAST Expansion and FAST Breakout Boards via a FAST Serial Protocol (FSP) connection to the EXP Bus. Please read the EXP Overview to understand the operation of these commands and addresses.

One of the primary uses of FAST Expansion Boards is to drive RGB LEDs. FAST Expansion Boards support WS2812-style serial RGB LEDs today, and in the future they will support APA-102 style LEDs, as well as RGBW LEDs. (Support for these additional LED types will be added via a future firmware update.)

A single FAST Breakout Board can support up to 4 ports with chains of up to 32 serial LEDs. (So that's a max of 128 LEDs per Breakout Board).

The FP-EXP-0071, and Neuron Controller's built-in Breakout Boards all support 4 chains of LEDs. The FP-EXP-0081 Expansion Board has 8 ports of LEDs, which is 4 ports addressed via built-in Breakout 0, and 4 ports addressed via built-in Breakout 1.

The actual LEDs are individually addressed via LED IDs 0 - 127. (Technically this is all in hex, so it's really 00-7F.) From a practical standpoint, this means that you set a breakout board to be active and then send commands to all the LEDs across all the ports for that breakout.

Here is the breakdown of the LED address numbering, divided per LED port:

Port Integer Range Hex Range
1 0-31 00-1F
2 32-63 20-3F
3 64-95 40-5F
4 96-127 60-7F

Remember that LEDs are technically connected to Breakout Boards, not Expansion Boards, so you'll need to address each command with a 3-character Expansion + Breakout address, either by setting the Breakout board to be active with the EA: command or by embedding the Breakout Board address into your LED command via the @ character.

LED Commands for EXP Bus LEDs

Here are the commands that are available to control LEDs. Since these commands only apply to the specific Breakout Board they're addressed to, whenever you see something that applies to "all" LEDs, it will be "all LEDs which are actively addressed" which would be all the LEDs of all the breakout boards if a 2-character Expansion Board address is set, or just all the LEDs of a single breakout board if a 3-character Breakout Board address is set.

  • RA: Set all LEDs to a certain color
  • RF: Set the default fade rate for all LEDs
  • RS: Set individual LEDs to be a certain color
  • RD: Set individual LEDs to be a certain color, binary command version
  • RL: Set individual LEDs to be a certain color over time (with fade), binary version

Documentation Feedback? Requests? Confused?

Hi! I'm Brian, and I'm responsible for the documentation at FAST Pinball. If you have any feedback, requests, corrections, ideas, or any other thoughts about this documentation, please let me know! You can email me at Thanks!

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