BG96/95 Locking up

Hi All

I would like to know if someone has had similar issue to what i am experiencing.

I am using the Quectel BG95/96. The module is powered with Li-poly batter 3.7-4.2V 2000mAh.

There has been few times, when the device has locked up where it id no longer functional, to get it back to normal i need to remove the battery.

Resting the module or powering up/down the module does not work, therefore the only option is removing the battery and re inserting it.

Has anyone else experienced such issues?

I am thinking that this could be due to my battery capacity?

The modules do have a peak current of 2A, therefore i am thinking even thou the batteries can output more then 2A for short periods, there could be a possibility there could be a short voltage drop below the min requirement of the module, causing it to lock up.

Could this be possible?

What battery capacity would be recommended to use?

Hello

We faced something like that. See if your battery voltage is dropping below the minimum voltage indicated by the datasheet … we used an oscilloscope, and even though the voltage measured on the battery was 3v7, when we connected to the network, the voltage dropped for a short period of time , and the modem no longer responded …

Another test to do is to use a stable and regulated source, so you eliminate the battery factor.

Hi

Thanks

When i remove the battery and re insert is it works again. Is there anyway to do this using AT commands? As even a reset does not work.

We are hoping to upgrade the battery to 4000mah from 2000mah.

What battery capacity did you use?

Hey,

I don’t know if a AT command would work, because in our case, the voltage drops and the BG95 resets…

We are using a 3v7 battery with 4000mah… when it is full charged (4v2), it works perfectly, but when the voltage drops around 3v6, the problems appears…

In your case, check if the capacitors on the module VCC line are good. We are using the configuration from the BG95 hardware datasheet. On the worst case, and for some test, you could use a 1mF thantalum cap on the line… we used that on other vendor module, and worked… but did not need on Quectel’s…

We had faced some other problems realated with the battery only operation, like unstable TCP connection… last week we got a new firware from Quectel, and it seems that the problems are gone… Check with your FAE for that too…

Hi

Thanks

So i guess once you reach 3.6V, the battery capacity must be less then 50%, therefore the same issue i am getting.

Yes i am using decoupling caps with a tantalum capacitor valued to 100uF.

When you say unstable TCP connection issues, whats sort of issues were these?

What was the version of the firmware for my refernce?

the version that we have is the “BG95M3LAR02A03_01.005.01.005”

Thanks

I have also been told that if you do get the lock up, it means device could have go into boot mode. You pulse RESET for 16 seconds and that should recover it.

What you ever had a file in the flash corrupted by any chance before?

Not realy… We use the module with a microcontroller, through AT command over the UART. Most of our problems are related with some module firmware bug… for example, we noticed that de PSM indicator pin is not working. We checked with quectel, and it is a firmware bug on their side again…

The TCP troubles we got were related to the USB connection, on the previous firmware… the TCP and MQQT only works if we got a PC connected through USB module… if used UART, the MQTT subscribe returns a error… it was fixed on the last firmware update.

Are you using the GNSS TX pin? It is another boot pin and it needs to be floating until the module starts complete…We did not notice that, and for some reason, it caused some trouble to us, related to the module entering in boot mode randomly…

Yes we had the GNSS TX pin issue as well, we had transistor circuit on that pin. We just removed the components , as we are not really using the GNSS pin.

We are not using USB for this project, therefore did not experience such usb issue.