VUSB pin on Argon

[rickkas7]

On the Argon, there's a 3 line function in this post that will do it:

Sensing AC power failure

OK, that was easier than I thought: #include "Particle.h" bool hasVUSB(); bool hadVUSB = false; void setup() { } void loop() { bool curVUSB = hasVUSB(); if (curVUSB != hadVUSB) { char buf[128]; snprintf(buf, sizeof(buf), "VUSB=%d", curVUSB); Particle.publish("power", buf, PRIVATE); hadVUSB = curVUSB; } } bool hasVUSB() { uint32_t *pReg = (uint32_t *)0x40000438; // USBREGSTATUS return (*pReg & 1) != 0; } Just copy and paste the hasVUSB…

On the Boron, Electron, and E Series, it's now built into Device OS 1.5.0 and later:

https://docs.particle.io/reference/device-os/firmware/boron/#powersource-