LC86G no response to commands issue

Hi I am having an issue with a LC86G module. It sends NMEA messages every second which I can see in serial. But it does not seem to respond to my commands. I have tried using the QGNSS software to send a change baud rate with ΝΜΕΑ command but it does not work either. I checked the physical connection to the chip and saw the pulses in an oscilloscope, also the command works perfectly in another GNSS module. To use the chip I replaced the L86 chip on a GNSS click board. Please tell me if there is some specific command to enable the NMEA commands. Thanks in advance,


to change baudrate you need to send the command an then to reset the modeule.

here are some commands I use to config my module, to get just RMC. I found that you have to run a delay between them.
Also, the module responds ACKing the commands or NACKink them.

I switch from L80 to LC86GLA last week, so I’m newby also…


Thanks for responding so quick,
I tried these but i still dont get any feedback. I am set to the correct baud rate and can see incoming messages. Do i need to do something on the hardware side? Did yours respond to changing the baud rate of the device out of the box?

Hi JasonM,

1)Please check if LC86G RXD pin is occupied.
2)Please check if you send commands with “\r\n”().

Best regards.

Hi Raphael,
I soldered wires directly to the pins on another LC86G module (which connects to a TTL converter), just in case i had some connection issue, but the results are the same. I have done the same thing on a L86 module. I am sending the commands via QGNSS V1.8.

This is the output from the L86 which does reply. I have tried the same command and the one above on the LC86G but it does not respond. There are no blank spaces. This is the output from LC86G

Hi Jason,

L86 and LC86G?? are quite differents.
Which LC86G are you using (LA, AA, AB)?

Attached my init file scrypt for QCOM 1.6

Configures LC86 to output GNRMC at 10Hz and nothing more.

LC86GLA (454 Bytes)

Regards, Gustavo.

Hi JasonM,

Could you provide me you schematic through message?

Best regards.

I think his schematic should be fine.

On the capture of LC86, the carriage return and line feed are displayed as: \r \n
However on LC86G, they become 0d 0a

The same command console is used to issue the same command but why the displayed message is different?

Hi, I have exactly the same problem.
After investigations, the device is responding when I send a lot of requests, a long time after the last request is sent.
Rx & tx are directly connected to the rp2040, levels on rx pin (of the gps) is a little bit low 2.48v in idle mode, power is 3.44v.

I receive nmea trames as expected, no read problem.

Any idea ?

Hi Etienne Cochard,

Did you receive the response to the commands you sent?

From your description, the module didn’t response to the commands immediately. Maybe the baud rate is too low for the UART communication. This will cause the serial port to be blocked. Please set the baud rate at least 115200 bps.

Best regards.

i have same problem using LC86G-EVB-Q1

yes i try your config but it didnt work.