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EHS5-E keeps resetting until USB is plugged | Telit Cinterion IoT Developer Community

April 1, 2017 - 9:48am, 2401 views

We have a softwareless EHS5-E (ARN14) on a PCB developed by us. EHS5-E keeps resetting itself in a 3-5 sec rhythm, see console screen capture attached. 


The last type out was ^SYSLOADING, after which restart occurred again.

Nevertheless if we connected the EHS5-E to an USB port, the resetting stopped immediately and the EHS5-E began to behave normally.  After we pull out the USB most devices, start to reset repeatedly again. Some don't!

Not all PCBs do exhibit this bad behaviour, only cca 15%, bad enough. I read in the documentation that, when USB is activated, the module is prohibited to enter the SLEEP state.

But I don't have a clue what exactly happens and who is to blame for it. Is it my PCB or the schematic to blame? Did it happen to you?

Claudiu Suma