Our customer has an existing device built around an embedded computer. They ask us to design and build a communication and localization subsystem so that they can extend the applicability of their product.
Since the application needs to interface to an embedded computer and multiple communication channels are required to be operated in parallel, we decide to build an USB-hub on-board our design. This way, a single high-speed USB link requiring only a single USB connection to the computer can cater for all communication channels.
The hub has 4 downstream client ports that connect to:
- an Sierra Wireless AirPrime MC module for 3G communication
- an SRT Marine Krypton AIS receiver
- an Iridium 9602 satellite modem
- an NXP ARM Cortex M3 processor running an AT-based control protocol
The ARM processor then interfaces to various on-board sensors, the GNSS receiver module, all antenna switches and the SIM card selection.
Power is provided through DC-DC convertors that regulate the PoE input net to the required on-board voltage rails.