I've just had my first batch of PCB prototypes delivered from the manufacturer, and when I went to program them, the target voltage is reading too low. The device is based around an Atmel SAM L21 MCU, and I've attached a schematic for reference. The power supply is 3 AA batteries in series, connected to a Microchip MCP1711 3.3 LDO voltage regulator. In Atmel Studio, when I try to read the target voltage, it reads either 0.2v or 0.3v. I assume that because there is a voltage being read, that power is reaching the board, but I'm not sure why it's reading so low.
Does anyone have any suggestions as to what might be the problem? I've tested the batteries and the reading between them is reading around 4.5v, as it should be. Could this be a problem with the Atmel ICE programmer?
Any suggestions would be great. Thanks guys!