Despite the recent popularity and breadth of offerings of low-cost RF microcontrollers, there is a shared absence of documentation for the internal workings of their RF hardware. Vendors might provide an API for their supported protocols, such as BLE, but their documentation will only provide as much detail as necessary to use these libraries. For practically every BLE MCU available to hobbyists, interfacing with the on-chip radio is limited to secret ROMs or binary blobs. In this talk, we will finally peel back the curtain on one of these RF MCUs, giving the ability to understand and unlock the full potential of the hardware to operate in new modes.