Adding MP11 support to a Sangean HDR-14

Recently I bought a Sangean HDR-14 radio, because I wanted to experiment with HD Radio emergency alerts. While some parts of the emergency alert system are described in the NRSC-5-E standard, important details are missing. For instance, the format of the control (CNT) data is not specified. As a result, some reverse engineering will be needed to bring emergency alert support to gr-nrsc5 and nrsc5.…