@neilh20 Yes, the chip supply pretty much put a spike in the Teensy 3.5 for any type of continued development and usage with that chipset. We used the 3.5 because of it’s 5V tolerant I/O. The Teensy 4.1 did not have that so the project stalled for a bit. I believe the folks who have taken that project over are considering moving the XBee to a Campbell Scientific datalogger.
Outside of that project I started building boards using the RP2040 microcontroller used in the RPi PICO. It’s very versatile, the drag and drop bootloader is a very nice feature and its still very much usable within the Arduino framework. Picture attached is a version used in one of our systems that mounts to a din rail and has the mounting holes built in for our fiber optic modem. RS-485/RS-232 on one side. Power and dedicated RS232 and power for the fiber modem on the left. Board communications with user for debug/loading are via usb although the part itself is missing in this picture (top right)