@ASH247iT I have created a branch of the pycom repository which includes btree. It is here: https://github.com/robert-hh/pycom-micropython-sigfox/tree/berkeley-db I can also provide you a firmware tarball for testing, if you tell me the Pycom module you are using (WIPY, FIPY, ...).

@Nazz Will need to do the opposite of what you've done here, send from the RPi, recvieve on the FiPy (see here: https://docs.pycom.io/chapter/firmwareapi/pycom/machine/UART.html#uartreadnbytes), and then do what ever sending you require.

@archana-kadam Normal LTE no.. unless you use a WiFi-LTE router (MiFi) or external LTE modem.

@robert-hh great thank you it worked perfectly!

Thanks for the suggestions! Still looking to get some examples how to serialize sensor data with MicroPython for TTN. All examples I found are for Arduino. Maybe @bucknall has some nice examples around?

@Ralph Thanks a lot for your quick answer. i will keep going with rshell.