--- /dev/null
+# RTOS and bare metal options for SAMD21
+
+[Zephyr](https://www.zephyrproject.org/]
+
+[Zephyr on Feather](https://learn.adafruit.com/blinking-led-with-zephyr-rtos)
+
+https://github.com/ataradov/mcu-starter-projects
+
+# Referenes on SAMD21 and Feather ecosystem
+
+
+[Zephy / Boards / feather m0](https://docs.zephyrproject.org/latest/boards/arm/adafruit_feather_m0_basic_proto/doc/index.html)
+ - documents the port assignments on the SAMD21 and interconnect on Feather
+
+
+# LoRa, LoRaWAN, and Feather
+
+https://github.com/svcguy/lorawanFeather
+
+https://github.com/kisom/lora-modem
+
+https://github.com/MKme/lora
+
+https://github.com/cbleg98/LoRa-High-Altitude-Balloon
+
+https://learn.adafruit.com/adafruit-feather-m0-radio-with-lora-radio-module/using-the-rfm-9x-radio
+
+