I can’t get my sketch to compile when I use: System.millis(); when trying to compile using WebIDE to compile against Particle Electron on a DeviceOS 1.5.2
I was able to compile that code for Electron 1.5.2 in the Web IDE. However, System.millis() returns a uint64_t. The error is most likely because the Web IDE is targeting a much older version of Device OS for some reason, not a missing include, which would probably cause a different error.