Oops. I’d meant to cut the code using NeoSWSerial and SoftwareSerial from that particular example but apparently cut it only from the example platformio.ini file.
Can you post your platformio.ini file? Are you using Atom or VSCode? It shouldn’t make a difference for the code; I’m just asking so I can help you better. What versions of all libraries do you have installed? Did you install any manually or let PlatformIO do the install? Are you sure you haven’t installed any twice? In your project’s folder, navigate to the .pio/libdeps/mayfly subfolder and look at all the folders within it. Do you see any library names in there twice (with a different suffix tagged onto the end of the folder name). If you see any repeats, the easiest solution is to delete everything and let PlatformIO reinstall just one version of each. Then update all your libraries and your platforms if you haven’t already. To do this, open a new terminal in PlatformIO with either the button or the menu. On Atom you can use the + icon on the bottom; on VSCode there should be a button on the very bottom left that looks like this: [> ]. In the terminal first update the platforms with the command “pio update”. Then update your project specific libraries with the command “pio lib update.” PlatformIO itself hasn’t been updated in a while, but you can verify that you’re running the lastest version with the command “pio upgrade.” After updating everything, make sure you clean out any older pre-compiled files by hitting the trashcan icon.
When you say the board restarts, does it restart instantly or does it hang for 15 minutes and then restart? Please add these defines to your platformio.ini file and then post the output when the board is running. It might be very long; you can post it or attach it as a text file.
; PlatformIO Project Configuration File
; Build options: build flags, source filter
; Upload options: custom upload port, speed and extra flags
; Library options: dependencies, extra library storages
; Advanced options: extra scripting
; Please visit documentation for the other options and examples
description = ModularSensors example using two "loggers" to save cellular data
monitor_speed = 115200
board = mayfly
platform = atmelavr
framework = arduino
lib_ldf_mode = deep+
lib_ignore = RTCZero