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RS: Set individual LEDs, EXP Bus Protocol Reference

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.

This command is used to set individual RGB LEDs to a specific color. You can chain together multiple LEDs and colors in a single command.

Note that there is also a binary version of this command, RD:, which might be more appropriate for your use case.

Command Syntax


<LED_IDX> is one byte, the index (number) of the LED you're updating.

<RGB> is three bytes of RGB color data.

You can update more than one LED at a time with this command by putting commas between each LED.

For example, to update three LEDs:

  • LED 01 - red (ff00ff)
  • LED 24 - yellow (ffff00)
  • LED 7A - blue (0000ff)

The command would look like this:


Breaking it down:

  • RS: command name
  • 01FF00FF set LED 01 to FF00FF
  • 24FFFF00 set LED 24 to FFFFOO
  • 7A0000FF set LED 7A to OOOOFF
  • <CR> at the end

If you have a global fade rate set (via a previously-sent RF: command for the board the LEDs are attached to), then the LEDs will fade to that rate over the given time.

Return Response


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