RB-Itb-02 crashing when plugging uFL antenna

Help & Support Robot Parts
1

Hello,

we’ve been struggling for about 1 week with this M95modem from Quectel.
Our setup is using a Raspebrry Pi3, a GPS module and an acceleroemetr module. programming is done using Android Things.
when modem without antenna is plugged using USB or direct 5v power, we can access the modem through UART and get some response to AT commands.
of course, we can’t reach the network because no antenna is attached.
when doing the same operations with a plugged uFL antenna, the modem can’t be reached. red light blinks fast, yellow led is off and no way to get any reponse from AT commands. Even the most simple ones. (like ATI)
We have read all the guides and documentation from itbranspower and tried different wiring setup with no success.
i’m quite out of solutions. any help would be great.
Best regards,

Pierre

2

Hi Pierre,

Thank you for the detailed description of your issue. We have contacted the manufacturer concerning this and we will get back to you shortly.

Sincerely,

3

Hello,

Just to let you know we’ve solved the problem. It’s quite tricky. This modem requires pluging a lipo battery or a supercapacitor on the Lipo+/- in order to provide enough current for the netwaork registration spike. At least 2A must be available for peak consumption.
I think you should update documentation in order for users to be able to use this great product.

4

Hi,

Thank you for the details. We received a similar response from the manufacturer, who also specified they had been contacted by you. :wink:

We will look at the documentation and refer your comments to the manufacturer.

Sincerely,