Vcore voltage drop below 1V | Telit Cinterion IoT Developer Community
April 23, 2016 - 7:02pm, 2004 views
Hi,
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)?
Thanks.
Hello,
which module do you have USB or LAN? If serial communication isn't working you could try to issue AT^SPOW=1,0,0 command over USB or LAN.
Regards,
Jure
Hello,
How do you connect UART interface, do you use RTS/CTS lines? By default the hardware flow control is active on the module. Another thing is what Jure already mentioned the sleep mode on serial intefaces which is also by default active. With RTS/CTS you should be able to communicate however there may be delays in communication with active sleep mode. Please try to connect RTS with CTS if you don't have the HW flow control on the other side.
The Vcore voltage is still in the allowed range. Please check if it will change when you manage to disactivate the sleep mode on UART.
Regards,
Bartłomiej