This is a good one. We're working with a FIWARE Lab in The Netherlands and a development partner to build an end-to-end integration with The Things Network and FIWARE.
The idea is that a custom application handler grabs the raw data from the MQTT broker of The Things Network, converts it to a XML format and posts it to ConCaVa (see https://github.com/kukua). ConCaVa does conversion, calibration and validation of binary data to a data structure. The data structure is stored in the FIWARE Orion context broker. Also, the structured data is updated in Orion for the concerning sensor.
We have a very rough set up working and currently in the process of getting the second phase approved.
Would this suit your requirements?