I am connecting L89H through a AMS1117 3.3v regulator which get 5v input. I am connecting the Pin 3,12 to gnd and 4,5 to 3.3v and 6 to an LED through a 1k resistor.
Also i am connecting the pin 2 which is the TXD pin to a HC 05 bluetooth module for getting the gps string in my app.
All other gps pins are open. The module gives nmea string for around 15 to 20mins and sometimes in get longer or shorter after that it some times stops or sending garbage strings. But the PPP led is still blinking.
I tried all possible ways by connecting a 0.1uf capacitor near to vcc and gnd of gps. tried connecting a 10 k pull up resistor on both RXD and TXD pins of GPS.
But some module works fine in the same board. Also once i get garbage string or no output then i switch off the module and switch on after 15mins then its start giving output and stopped.
I am confused. Any help.
Can i get the latest firmware for the L89H R2.0
Hi Binu_Johnson,
Can you check if there is the same issue when reading UART directly from L89HA pin1&pin2 through TTL-USB convertor?
Perhaps there is some buffer in the host and it is full.
I’ll send you the latest firmware through email.
Best regards.
I think the problem is, i kept the wakeup pin open and when i connect it to ground then the module is working fine.
Hi Binu_Johnson,
This issue shouldn’t be caused by WAKEUP pin. This pin is dedicated to wakeup module from backup mode, when you drive the pin to high level. If backup mode is not used, you can keep it not connected.
Can you check if the other GND pins are properly connected to the groud?
Best regards
Yes you are correct, the WAKEUp pin is not the problem,
i am using L89H R2.0 gps module with a bluetooth receiver. Here is the circuit.
I have few doubts, is the 1k resistor is compulsory in the circuit, since i tried without the resistor and some times the output is stopped after few minutes.
Also with some modules i am getting this output with gps fix data
$PQTMANTENNASTATUS,1,0,14F
$PAIR001,001,238
$PAIR001,001,238
$PAIR001,001,238
$PAIR001,001,238
$PAIR001,001,238
whats the meaning of above output, i am not connecting anything to the antenna pin as show in the circuit.
i am getting $GNRMC, $GNGGA, $GNGSA and others with the above for every second.
Where is the problem. Do i need to use any UART Buffer in between the TXD of gps and RXD of bluetooth module?
Thanks
Binu
Better connect ground to both boards
$PAIR001,001,2*38
are acknowlege for ephemerides
antenna status here (1 = Open circuit; mode: 0 =Automatic;1 = Power on)
Quectel_L89(HA)_GNSS_Protocol_Specification_V1.1.pdf (778.5 KB)
and
Quectel_L89 R2.0_GNSS_Protocol_Specification_V1.0_Preliminary_20200429.pdf (367.5 KB)
Regards
