[MC60] Cannot get GSM and GPS to work at the same time

Hi there.

I already posted about this problem in a different section, but as I got new details I felt like the previous post is badly worded now. That’s why I repost here.

TL;DR : I cannot get the GPS and GSM to work simultaneously. Whenever I use GSM, the GPS stops working and always return the same string. Same date, same timestamp, same position, same everything.

A bit of context : I’m working on a GPS-based car tracking project. I have a board with a MC60 on it that’s plugged to an Arduino Uno board.

The project goal is as follow : get a GPS fix, process the data and send the result through UDP to a server of mine. Once every second.

I got almost everything to work perfectly. I’m able to connect to the internet, send data, connect to the GPS system and get a fix.

Here is the issue : Things get bad when I try to send the received fix to my server. As soon as I send data (the MC60’s network led starts to blink faster), the GPS stops working. From that point it always returns the exact same string.

Here is what I do in my program (pseudo code) :

AT+QICSGP=1,"<APN_NAME>",,\r
OK

AT+QIDNSIP=1
OK

AT+QGNSSC=1
OK

AT+QIOPEN="UDP","<DOMAIN_NAME>",<PORT>"
OK
.
.
.
CONNECT OK

loop {
    AT+QGNSSRD="NMEA/RMC"
    if (valid fix) {
        AT+QISEND=15
        >
        <15 bytes>
        SEND OK
    }
}

Before the GPS get a fix, I can see the NMEA sentence it outputs are correct. They update on every call to the AT+QGNSSRD command.

As we can see here the fix’s timestamp changed every second as it should.

But as soon as I get a fix and send it through UDP, the fixes stop updating :

On this picture we can see that the exact same string is returned by the MC60.
Important : According to this picture the commands and their responses seem to overlap. This is due to recording software. The following picture shows what actually happens and this is indeed not the case.

So I would like to know how to be able to use GSM and GPS at the same time. I suppose it’s due to some configuration that I don’t set properly or not at all but I can’t find any solution on the internet nor in the various documents I’ve read.

I can try to provide more logs and my code if needed. I’m not using any Quectel tool, I’m coding straight from the terminal and flashing with avrdude if that matters.

Thanks in advance for any help !

This phenomenon is abnormal. Please send an email to stephen.li@quectel.com , pls help us to collect the log for more analysis