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Vcore voltage drop below 1V | Thales IoT Developer Community

April 23, 2016 - 7:02pm, 1698 views


i am using th EHS6.

When I power up the module, I see 1.8V on the v180 line, and 1.186V on the Vcore. After a couple of seconds, v180 remains at 1.8, whereas Vcore goes to 0.976. I can see "SYS LOADING" and "SYS START" on uart0.  But when I try to communicate with the module using simple AT commands, I get no response at all.

We have already communicated with the EHS6 on another board so we are sure we are sending the right command.

Vbat is a 3.8V stable power supply with adequate current. (I tried several supplies)

Vddlp is connected via 10k to V180. RST and Shutdown are not connected. I am starting the module with auto on signal. ON is just connected via 100k to GND. Nothing else is connected, except the UART.

Needless to say, the module is new and there is no software on it.

What can be the reason for the low voltage on the Vcore? What could be the reasons the module doesn't answer AT commands? (but it does send SYS LOADING when I power it up)?