Groove shield SIM28 GPS module behaviour

This happens most of the times once a day, it seems the SIM28 looses its configured baudrate (57600) and falls back to default of 9600 anyone else seeing this behaviour ?

$GPGGA,112606.000,5214.3861,N,00447.4096,E,1,8,0.97,-6.7,M,47.0,M,75
$GPRMC,112606.000,A,5214.3861,N,00447.4096,E,0.86,104.12,210216,A
60
Garbadge
-snip-
Garbadge
No valid input for 15 seconds
sGarbadge
HGarbadge
$PMTK001,314,3*36
$GPGGA,235957.799,0,0,M,M,40
$GPRMC,235957.799,V,0.00,0.00,050180,N
49
$GPGGA,235958.799,0,0,M,M,*4F


When there is 15 seconds without a valid input, the sketch will re-initialize the baudrate and the nmea sentences sent - Looking at the above input it appears the SIM28 does a cold restart without any apparent reason (which makes it fall back to 9600 baud). I’m happy the SODQ designers use an ublox instead :slight_smile:

It would appear that there is some bug in the firmware which is causing it to reset. If it is not possible to set the default baudrate, then you may have to try a detect these events. The NMEA sentences should be coming through at very regular intervals, perhaps if you fail to get a valid message for 20s you could try switching the baudrate back to 9600 and then sending the command to change it to the higher rate?

Yep, that is what I’m doing now after 15 seconds of invalid input it resets the baudrate …

void setupSIM28 () {
Serial.begin(9600);
Serial.flush();
delay(500);
MicroNMEA::sendSentence(Serial, “$PMTK251,57600”);
delay(500);
Serial.begin(57600);
Serial.flush();
delay (500);
MicroNMEA::sendSentence(Serial, “$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0”);
}