1. Download the most recent version of the following files in the same directory:
https://github.com/particle-iot/device-os/releases
photon-bootloader@1.4.4+lto.bin
photon-system-part1@1.4.4.bin
photon-system-part2@1.4.4.bin
photon-tinker@1.4.4.bin
2. Open terminal
3. access the directory of the downloaded files:
cd <directory>
4. Run these command lines one at a time (note that the files / version may change with time)
particle flash --usb photon-system-part1@1.4.4.bin
particle flash --usb photon-system-part2@1.4.4.bin
particle flash --usb photon-bootloader@1.4.4+lto.bin --force
particle flash --usb tinker
5 (optional). Reset the wifi connection:
particle setup
6. Run tests with the online IDE (try signaling the device) and try flashing blink (the example code)