Hi Alex, I am not sure if there is something common with the following project, but you can take a look at it: https://github.com/teco-kit/Jennisense/wiki
Thanks, but nope - Contiki is interesting for integrated transceiver MCUs or SoCs like Atmel RF230, Atmega128 RFA1, ST STM32w, TI CC2420… but a Jennic JN5139 is not only EOL (read: end of life, dead, outdated, obsolete) but more expensive than a full packed Wilssen with all sensors. 
I want to keep it inexpensive and as open as possible