RTK Surveyor: BT suddenly fails

GPS/GNSS Development Boards
1

SPX-17369 SparkFun RTK Surveyor

Order number: 6499673

Order date: Saturday, February 20, 2021

Received: 2/26/2021, first used ~ 12 March

At first things went quite well. I am using a Lenovo Tab M10 FHD Plus

wih Android 10 to run the latest SW Maps.

SW Maps communicated via BlueTooth with the RTK Surveyor and the data was

wonderful (and SW Maps too).

But today (Sunday) it suddenly ceased pairing - it was OK before lunch,

but dead when I came back to it.

The blue pair light blinks, but does not connect. When I try to

connect, either via SW Maps or Android’s “Connected Devices”, an

error is reported.

I checked with a desktop Mac and an iPad and neither shows the RTK in

the list of discoverable BlueTooth devices (I know it won’t work with

an Apple computer, but it should show it as a possible BlueTooth device)

The yellow PPS light blinks, suggesting that the u-blox is still

functioning and receiving satellites.

The SparkFun forum #223233 suggested checking inside that both switches

are up, so I checked checked & cycled the switches in case they were

making a poor connection. No change…

Battery is fully charged.

I searched the Forum extensively, but could not find any postings

relevant to my issue.

So, I am at a loss as to what the next trouble-shooting step should be.

Since the u-blox appears to be working, iI suspect the ESP32 WROOM , which

appears to be in charge of BT communications, may have bit the dust…

Help!

Cordially,

–

Garth Fletcher

2

Thanks for the good breakdown of the problem! I don’t have a smoking gun yet but a few ideas.

You mentioned ‘an error’. Please oh please share that error contents and/or a screenshot from your phone or tablet showing it. The blinking blue LED indicates the ESP32 is running so it’s very odd…

Are you running the unit in base or rover mode?

Where you doing anything with the NTRIP caster settings? This is normally done over USB using the serial menus to setup a base station and NTRIP mode. I ask because this setting will disable Bluetooth once a survey is complete and enter WiFi mode which is the only way I think the ESP32 could be failing to do BT.

With no other ideas, I recommend doing a factory reset. This entails

  • hooking up USB to the ESP32 config port

  • opening a terminal at 115200bps

  • press any key to bring up the serial menu system

  • press ‘r’ for reset

  • press ‘y’ to confirm

This will remove all settings, setting files, and reset the ZED-F9P.

Sorry it’s giving you trouble! Let us know how it goes.

3

Thanks for the good breakdown of the problem! I don’t have a smoking gun yet but a few ideas.

You mentioned ‘an error’. Please oh please share that error contents and/or a screenshot from your phone or tablet showing it. The blinking blue LED indicates the ESP32 is running so > it’s very odd…

** “GNSS intrument connection failed”. Also once very briefly saw “xxx 133” where xxx was some capital letters which I didn’t catch. Could not replicate.

Are you running the unit in base or rover mode?

** Rover mode

Where you doing anything with the NTRIP caster settings? This is normally done over USB using the serial menus to setup a base station and NTRIP mode. I ask because this setting will > disable Bluetooth once a survey is complete and enter WiFi mode which is the only way I think the ESP32 could be failing to do BT.

** no

With no other ideas, I recommend doing a factory reset. This entails

  • hooking up USB to the ESP32 config port
  • opening a terminal at 115200bps
  • press any key to bring up the serial menu system
  • press ‘r’ for reset
  • press ‘y’ to confirm

This will remove all settings, setting files, and reset the ZED-F9P.

Just did that.

As soon as the connection is established I get recurring lines:

"Rover Accuracy (m): 429496.7187 No LEDs

Rover Accuracy (m): 429496.7187 No LEDs

Batt (92%): Voltage: 4.20V Discharging: -3.74%/hr Green all good"

Note: antenna is not connected and I’m indoors, so no blinking yellow led.

When I type a char (return) I get the serial menu system

SparkFun RTK Surveyor v1.1

** Bluetooth broadcasting as: Surveyor Rover-083E **

Menu: Main Menu

  1. Configure GNSS Receiver

  2. Configure Data Logging

  3. Configure Base

  4. Configure Ports

r) Reset all settings to default

t) Test menu

x) Exit

I then type ‘r’

Resetting to factory defaults. Press ‘y’ to confirm:

Settings erased. Please reset RTK Surveyor. Freezing.

[Disconnected]

Power cycled it and tried again - same results

I then tried to pair with it - same failure.

NOTE: in my Android in Settings > Connected devices it shows “Surveyor Rover-083E”

if I turn off the Surveyor and tell Connected devices to forget it

when I then go to Pair new device", it doesn’t show.

If I then turn the Surveyor back on, it reappears in the Android’s list of available devices

So, it is working to the extend to broadcasting its availability.

However, selecting it and trying to pair results in the same “GNSS Instrument Connection Failed!” message.

Testing with my Mac running OS X 10.13.3 (High Sierra), the Surveyor Rover-083E shows up in the list of BT devices.

Clicking on “Connect” goes through a sequence of “Connecting” then “Connected” then “Connection failed”

4

As of this afternoon the problem appears to have disappeared!

Truly mystified, but very happy :slight_smile:

So, no further action needed. I will report back if the problem reappears.

Many thanks for the suggestions.

5

Very odd indeed. I agree with everything you said - device is broadcasting and seems to be doing what it should. Not sure how the ESP32 was misbehaving but glad to hear it’s settled. Please let us know if anything pops up.