Help With F9P Comm Not Responding

GPS/GNSS Development Boards
1

Hi, i have issues with comm ports (UART1 and I2C) of ZED F9P suddenly not working and unfortunately i don’t have an extra module. It was working flawlessly through either I2C or UART1, but suddenly without any changes made, the comms won’t work.

For clarity, at first i was using the gps module using I2C and last time migrated to UART1 both comms working great. After the testing returns good data, i haven’t touch anything and didn’t sure if i have closed the connection yet or not but i think it’s still powered on 24/7. After less than a week, i came back and found out that the comms returns error. I have tried to check it through USB and u-center it doesn’t show any errors even shows it receives some satellite data. Checking further using UART1 and I2C give no difference. Using i2c, i have tried to double check the address on u-center and scanning through the i2c address using esp32 but to no avail.

I am trying to debug the problem and the debug output from Sparkfun GNSS V3 Library is below

UART1 Debug:

createFileBuffer: Warning. fileBufferSize is zero. Data logging is not possibl.
getVal key: 0x10730001


Sending: CLS:CFG ID:0x8B Len: 0x8 Payload: 0 0 0 0 1 0 73 10
sendCommand: Waiting for ACK response
waitForACKResponse: TIMEOUT after 1100 msec.
getVal: sendCommand returned: Timeout
begin: isConnected - second attempt
getVal key: 0x10730001


Sending: CLS:CFG ID:0x8B Len: 0x8 Payload: 0 0 0 0 1 0 73 10
sendCommand: Waiting for ACK response
waitForACKResponse: TIMEOUT after 1100 msec.
getVal: sendCommand returned: Timeout
begin: isConnected - third attempt
getVal key: 0x10730001


Sending: CLS:CFG ID:0x8B Len: 0x8 Payload: 0 0 0 0 1 0 73 10
sendCommand: Waiting for ACK response
waitForACKResponse: TIMEOUT after 1100 msec.
getVal: sendCommand returned: Timeout

I2C Debug:

createFileBuffer: Warning. fileBufferSize is zero. Data logging is not possible.
begin: isConnected - second attempt
begin: isConnected - third attempt

I2C Scan: Just reports no i2c address found

From the debug output, it seems that the comm is dead but i can’t think of the reason why. And why USB connection doesn’t affected?

2

Hi Sami,

Have you accidentally changed the module’s I2C address? Or disabled the UBX protocol on I2C? Either of those will cause the failure you are seeing.

I suggest resetting the module back to its default settings. Use u-center to connect to the module over USB. Open Messages View and navigate to UBX-CFG-CFG. Select “Revert to default configuration” and click “Send”. Then “Save current configuration” and “Send”.

Then try your I2C code again.

I hope this helps,

Paul

3

Hi Paul,

I haven’t changed any configuration beside changing UART1 baud rate to 57600, and set up so the output and input in UART1 is using UBX protocol so i can use UART1 instead of I2C

I’ll try to revert to default config using u-center and get back to you soon

4

Hi Sami,

Resetting the configuration is the first thing to try. After that, it is a question of checking the I2C interface. Please tell us which microcontroller board you are using. Is it 3.3V? Or is it possibly a 5V board like the Arduino Mega? The IO voltage difference will cause problems if you are using a 5V board. Also check the Qwiic cable / jumper wires. It’s rare, but the Qwiic cables do sometimes fail. Try swapping the cable with a known-good one.

I hope this helps,

Paul

5

The SPI solder bridge would map 4-pin SPI instead of I2C/UART

In SAFEBOOT mode, say firmware corrupt, the default baud rate would be 9600 instead of 38400

Perhaps check in you get periodic output on the UART1.TX pin, should get a burst of NMEA data once a second.