[woodcote]

The Slot.it crew have recently updated the various oXigen manuals (http://slot.it/oxigen/) which is what I used...

• Base O2 Manual - overview and pairing process etc
  
• O2 Car Chip C - using nRF Toolbox app with the C and B2 chips.
  

You do need the oXigen dongle and bootloader to update firmware on the SCP and SCP2. The bootloader has just been rewritten by the RCS64 team and the documentation on the Slot.it site hasn't been updated. If your SCP2 is fairly recent, the firmware should be perfectly fine for now.

The same with the C chip - it is loaded with O2 firmware by default. It will work, even if it's not the very latest firmware version. The crucial thing is to have the chip set up with the correct AC or DC setting for your track (SSD = AC) and be able to pair the chip to the controller. The rest is useful to know how to do, but not essential.