BGS5T VCCREF reboots | Thales IoT Developer Community
December 10, 2016 - 1:22am, 8681 views
I have a simple PCB with a jumper used to choose between +5V from the module or an external 3.3V source. For some very strange reason once the module is connected to the PCB the module will reboot if +5V is connected to VCCRef. Even after removing and connecting +5V to VccRef the module will continue to reboot.
The reboots seems to coincide when using an internet connection, perhaps due to higher power usage. When connected to the PCB but without the jumper connected everything works and is stable. Even the inputs and outputs work correctly. This is even more strange because in this situation VccRef is not even connected to anything yet the digital inputs/outputs work. By change measuring VccRef when it is disconnted reads about +2V.
What is very concerning is that when VccRef is disconnected things work which not how it should be according to the datasheet. When +5V is connected to VccRef the module reboots normally during network usage, but not always but roughly %90.
We have used simple code and various midlets to rule out programming issues but the reboots continue. The module reboots without any warning or error message.
No special scenario, no hardware connected. I have only one terminal.
Sometimes it reboots every 15/20 seconds, sometimes it works well.
I still haven't found a 'trigger' for this rebooting loop but removing +5Vout-VCCref connection will ALWAYS solve the problem; when I'll reconnect 5V to VCC it starts again.
I was not able to reproduce this constant rebooting scenario just after connecting 5V to VCC with my hardware.
So I think that it might be a good way to report this to your local hardware supplier and maybe ask for replacement. Or maybe thy could report it to Gemalto support.
Because it seems to be a hardware problem and I can't reproduce it with my device there's not much I can do more on this public forum without the access to the failing device.
That is why I have suggested to report it to the Gemalto support line system - then there would be a possibility to send your device (where the problem is reproducible) for analysis and tests, your hardware design could be reviewed etc. - there will be much more possibilities.