While getting ready to add a switch, with a 10KΩ pull down resistor to Gnd, and the other end of the resistor connected to the WKP pin, the the other side of the Normally Open switch is connected to the 3.3V pin on the Electron. (This was to simulate waking from DEEP SLEEP from a Rising signal from a water detection device.
I hooked up my DMM to the 3.3V pin right at the Electron and the voltage measures 3.34V with Li battery connected and cellular radio on, (No Sleep). When the Electron goes into DeepSleep the voltage jumps to 4.38V, in both cases the USB is connected. The Electron is plugged into a Particle Shield Shield. No Voltage on Vin.
Reading the Electron datasheet, 3V3 -This pin is the output of the on-board regulator. When powering the Electron via VIN or the USB port, this pin will output a voltage of 3.3VDC. The max load on 3V3 is 800mA. It should not be used as an input to power the Electron. This seems like the 3.3V regulator is not working correctly. Has anyone else seen this behavior ?
By the way, the switch simulation worked as expected, waking from System.sleep(SLEEP_MODE_DEEP, 60 * 20, SLEEP_NETWORK_STANDBY); The Console-Events displayed the Data in celsius, on a normal Wake Up after 20mins. it displays the data in Fahrenheit.