The BB4IO peripheral controls the buttons and LEDs on the Baseboard4 FPGA card. BB4IO is part of pccore.bin if the image is build for the Baseboard4.
Each Baseboard4 has three buttons (S1, S2 and S3) and eight LEDs (LED0 to LED7). More information about the Baseboard4 is available here: /cards/baseboard4.html
The LEDs are tied internally to the first eight user IO pins. That is, they are tied to the FPGA pins available on connector SV1 which corresponds to slots one and two.The BB4IO peripherals replaces the enumerator on a succesfull load of the FPGA image and start of pcdaemon. BB4IO includes the list of peripheral IDs built into the enumerator.
Resources:buttons : The value of the buttons as a number between 0 and 7. The LSB has the status of Button 1. This resource works with pcget and pccat.
drivlist : This is a read-only resource that returns the identification numbers of the drivers requested for the peripherals in the FPGA build. It works only with pcget and returns sixteen space separated hex values.
Get the list of peripherals IDs for this FPGA image.
pcget bb4io drivlist
Watch for button press and release events as a stream.
pccat bb4io buttons