Adafruit Feather M0 Single Board Computer with RFM95 LoRa Radio - 900MHz

satisfied the use intended

Works great and lots of excellent support!

This board is worth the money. As a long time radio enthusiast and electrical engineering hobbyist I’ve often been fascinated with portable radio devices. I’ve built many using Arduino and HC-12 radios. My devices often consisted of an: Arduino Pro Micro HC-12 radio module Lithium ion battery module. Rotary encoder Oled screen These items took a long time to wire and solder together on a prototyping PCB. When my device was finished the footprint of my device was 4-5 times larger than the Feather M0 LoRa board. I use the Feather M0 LoRa with their Featherwing OLED shield that goes on top of it. It has 3 buttons which I use to control a menu on the OLED so I don’t need the rotary encoder. Essentially this board out the box is better than what I used to do. Feather M0 LoRa Pros: 1) the M0 chip uploads so much faster than the old Arduino boards I used to use. It also has way more storage space. I used to max out the old boards. Now my 2500 lines of code only takes up 18% of the space. That menus I can make my menu options almost endless. 2) built-in lithium ion/polymer better connector. (Can switch board off by attaching switch to “EN” and “GND” pin. ) 3) lots of Adafruit featherwing add-on boards. The 128x64 pixel OLED add-on is my favorite. It gives you 3 buttons built onto it. Unfortunately it seems button “A” drops the voltage measuring pin to zero. This makes displaying a battery voltage get interrupted when you press “A”. You can still read the voltage in your sketch, but it takes some work arounds. Hint: Use “analogWrite(A7, 255);” after reading voltage to return the button state to HIGH so it behaves normally again. (Button “A” pin is actually connected to pin “9”, but for whatever reason it still affects pin “A7” which is the pin used to measure the battery voltage on the M0 chip. Voltage will measure as zero temporarily when you press button “A”. This is my only frustration with this board. ) 4) Radio range - In my testing I got about a half-mile range line of sight with just the soldered on coil antenna. You can buy a surface mount SMA antenna socket from Adafruit that you can solder to the bottom of the Feather M0 LoRa board. This allows you to use a higher gain antenna with an SMA socket. I haven’t tested the LoRa boards with an SMA antenna yet. I have used SMA antennas on the HC-12 boards and it helps a ton. If you got this route make sure you buy the right antenna for the frequency of your LoRa module. (433MHz or 915MHz) 5) Extremely compact. This board is small and packed with features making it easy to make something portable and battery powered which is all I like to do. This is a great board and it’s worth the time learning how to use LoRa. HC-12s are a lot easy to use, but now that I’ve learned how to use LoRa these will be my preferred boards. Kind of pricey especially after you add the OLED module, but there isn’t anything better out there for making portable wireless devices.