EA: Set the active EXP board address, 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.
The EA: command is used to set the "active" board. When an EA: command is sent, all subsequent commands without embedded addresses will be processed by the board that's active.
This command can be used with 2-character addresses for expansion boards, and with 3-character addresses for a specific breakout board on that expansion board. (Note that most commands are designed to be addressed to either an expansion board or a breakout board.)
In practical use, this command will almost always be used with a 3-character address for a specific breakout board. The 2-character expansion board addresses tend to only be used during startup (via ID: commands to confirm the boards are responding), and via other occasional things (like the BR: command which is typically sent to reset the machine hardware once a game is over.)
The EA: command does not provide feedback. If an invalid board address is used, you will not know it. If you want to confirm that the EA: "worked", you could send an ID: afterwards. (This is not recommended for your general use code, but it's nice when you're playing around via a terminal emulator). For example:
ea:b4
id:
ID:EXP FP-EXP-0071 0.8
Or, if you want to get the ID of a specific breakout board:
ea:b40
id:
ID:BRK FP-EXP-0071 0.0
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 brian@fastpinball.com. Thanks!
N or > jump the next page, P or < for previous, search with S or ?