https://www.thethingsnetwork.org/labs/story/build-the-cheapest-possible-node-yourself

https://www.thethingsnetwork.org/community/berlin/post/how-to-build-a-simple-and-very-cheap-lorawan-node-with-arduino

https://www.thethingsnetwork.org/forum/t/cheap-and-simple-lora-node-for-schoolproject/22364/5

https://forum.iot-usergroup.de/t/nucleonbasenode328-arduino-328-pro-mini-lora-gehaeuse-antenne/287

Wahrscheinlich dieses hier:
---------------------------
https://forum.iot-usergroup.de/t/wijnand-s-iot-battery-sensor-board-weiterentwicklung/339/2

http://alf4all.demon.nl/engineering/topics/digital_system_design/targets/Arduino-Pro-Mini_RFM95/index.htm

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Ended up buying these: 
----------------------
https://www.banggood.com/2Pcs-LILYGO-TTGO-LORA32-868Mhz-ESP32-LoRa-OLED-0_96-Inch-Blue-Display-bluetooth-WIFI-ESP-32-Development-Board-Module-With-Antenna-p-1507044.html?utm_design=41&utm_source=emarsys&utm_medium=Neworder171109&utm_campaign=trigger-emarsys&utm_content=winna&sc_src=email_2675773&sc_eh=4a6c1db81031fa671&sc_llid=15150285&sc_lid=105229698&sc_uid=OCFpZipIvn&cur_warehouse=CN

Repo:
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https://github.com/lemariva/uPyLora

Tutorial:
---------
https://lemariva.com/blog/2018/10/micropython-esp32-sending-data-using-lora

https://primalcortex.wordpress.com/2017/11/24/the-esp32-oled-lora-ttgo-lora32-board-and-connecting-it-to-ttn/

Demodulation:
-------------
https://electronics.stackexchange.com/questions/278192/understanding-the-relationship-between-lora-chips-chirps-symbols-and-bits
