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SN: Configure a switch

FAST Serial Protocol: Overview & First Steps

This documentation section is about the FAST Serial Protocol (FSP) commands, which are the low-level commands a host computer sends to a FAST board. Most FAST Pinball makers do not need to know about these details, since the pinball game framework (such as the Mission Pinball Framework) handles this communication for you.

If you're writing your own game framework, read the overview of how FSP works and how to connect first.

Note that this SN: command is valid for the FAST Nano Controller and prior. FAST Retro Controllers, the FAST Neuron Controller, and newer controllers using the "v2" NET platform use the command SL: instead of SN:. All syntax and parameters are the same.

Configure debounce times and output parameters for a switch



Any switch ID number, in hex.


0 = Do not report any switch state changes to the host computer.

1 = Report normally.

2 = Report inverted, for "normally closed" (NC) or opto switches.


Time to debounce switch close in ms. Default 2 ms (02 hex). 256 ms max (range 00-FF hex).


Time to debounce switch open in mS. Default 20 ms (14 hex). 256 ms max (range 00-FF hex).



Set switch 0x02 to report normal, debounce close time is 32 ms (20 hex), Debounce open time is 16 ms (10 hex).



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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