Postcard RTK: Unable to connect to Bluetooth serial configuration while in base mode.

[amlago]

Postcard RTK: Unable to connect to Bluetooth serial configuration while in base mode.

I regularly use the Postcard RTK in base mode, and it would be useful to be able to access Bluetooth serial configuration to make changes.
While in base mode, the Bluetooth serial configuration doesn't connect.
As a reminder, Facet does allow this.
Limitations of the Postcard RTK?
Regards

[nseidle]

@amlago - Thanks for reporting. Please let us know what version of firmware and Bluetooth settings you are using.

[amlago]

Hello.
I'm using v2.3 and Bluetooth Classic.
Best regards,
Angel

[PaulZC]

Hi Angel (@amlago ),

Is this issue linked to the LG290P v06 firmware? Do you see the same behaviour with v05?

Could it be related to issue 719? That issue has been resolved since early September, the fix is present in the latest RC v2.3. Did you create your profile using v2.2? If so, please try deleting that profile and create it again.

Thank you,
Paul

[amlago]

Hi Paul.
I was having the same problem with v05 of the LG290 and version 2.2.
After putting the postcard in dock mode, I lost the ability to connect via Bluetooth.

[amlago]

Regarding issue 719, I've never tried creating new profiles.
I only have one profile.

[PaulZC]

@amlago : OK - thank you,

I am trying to replicate your issue:

With Postcard running today's release_candidate
LG290P is running v06 firmware
Reset to factory defaults using s r y
Leave BT in Dual mode for now
Leave firmware in Rover mode for now
Pair my Android phone with the Postcard Rover-A4DA
Open Serial Bluetooth Terminal
Connect to the Postcard - using Bluetooth Classic
NMEA is observed
Send +++
Menu is observed
Send x
Close the connection

Put the firmware into Base mode - I do this via the USB-C Serial connection and Tera Term
Wait for the survey-in to complete
OLED shows Xmitting
I do not see Postcard Base in the available devices...

I restart the firmware using the Serial console and s d r
Firmware restarts in Base mode
Wait for the survey-in to complete
OLED shows Xmitting
I still do not see Postcard Base in the available devices...
But I do see Postcard Base-A4DA in the paired devices!
The name has changed to reflect the Base mode.
In Serial Bluetooth Terminal I see a mess of binary RTCM plus NMEA
Sending +++ opens the menu
Menu is observed
Send x
Close the connection

Was the restart essential? Or did I just miss the paired name change?
Do over...

For completeness, on my phone, I unpair all previously paired devices and turn BT off and on again
Reset Postcard to factory defaults using s r y
Leave BT in Dual mode for now
Leave firmware in Rover mode for now
Pair my Android phone with the Postcard Rover-A4DA
Open Serial Bluetooth Terminal
Connect to the Postcard - using Bluetooth Classic
NMEA is observed
Send +++
Menu is observed
Send x
Close the connection

Put the firmware into Base mode - I do this via the USB-C Serial connection and Tera Term
I see "Bluetooth SPP and BLE broadcasting as: Postcard Base-A4DA" in Tera Term
Wait for the survey-in to complete
OLED shows Xmitting
In my phone's Bluetooth settings, I do not see Postcard Base-A4DA in the available devices
I still see Postcard Rover-A4DA in Paired Devices
I turn the phone Bluetooth off and on again
In Paired Devices, the name of the Postcard has changed to Postcard Base-A4DA
If I try to connect with Serial Bluetooth Terminal, I see "Connection failed: read failed, socket might closed or timeout, read ret: -1"
I close the Serial Bluetooth Terminal App and reopen it
I try to connect again and I see the same "Connection failed" error

I restart the Postcard firmware - I do this via the USB-C Serial connection and Tera Term (s d r)
Wait for the survey-in to complete
OLED shows Xmitting
Now I can connect with Serial Bluetooth Terminal
Send +++
Menu is observed
Send x
Close the connection

OK. It looks we have a reconnection issue, possibly caused by the Bluetooth device name change?

Do over. This time I will change to Base using Serial Bluetooth Terminal
I unpair the Postcard on my phone
I factory reset the Postcard firmware
I turn my phone Bluetooth off and on again
I see Postcard Rover-A4DA in available devices
I pair
In Serial Bluetooth Terminal, I connect and open the menu
I put the firmware into Base mode with s B x x
I see "Connection Lost" - I think this is expected
Firmware restarts in Base mode
Wait for the survey-in to complete
OLED shows Xmitting
If I try to reconnect with Serial Bluetooth Terminal, I see "Connection failed: read failed, socket might closed or timeout, read ret: -1"

I close Serial Bluetooth Terminal
I unpair the Postcard
I turn my phone Bluetooth off and on again
I see Postcard Base-A4DA in available devices
I pair
In Serial Bluetooth Terminal, I try to connect but I see the same "Connection failed" message

I power the Postcard off and on again
It restarts in Base mode
I wait for the survey-in to complete
OLED shows Xmitting
In Serial Bluetooth Terminal, I can connect and open the menu

It seems that - with today's release_candidate firmware - we need to reset or power-cycle the Postcard to be able to (re)connect on Bluetooth in Base mode

@amlago : does this match what you are seeing? Are you able to connect if you power-cycle the Postcard? Thank you.

[PaulZC]

Notes:

@nseidle has been making changes to the Bluetooth connection, to add a new, separate "command" interface (for future Apps) and a Battery Service (so the battery charge % is displayed correctly in Apps). Maybe some of the changes have caused this reconnection issue?

[PaulZC]

Interesting... In Base mode, we bluetoothStop() then bluetoothStart() :

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/States.ino

Lines 226 to 227 in d9bef99

	bluetoothStop();
	bluetoothStart(); // Restart Bluetooth with 'Base' identifier

But in Rover mode, we only bluetoothStart() :

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/States.ino

Line 113 in d9bef99

bluetoothStart(); // Turn on Bluetooth with 'Rover' name

Could the Base bluetoothStop() be causing issues? But it seems more likely that Rover should have bluetoothStop() too?

[PaulZC]

Oh, fascinating!

If I comment the bluetoothStop() in STATE_BASE_NOT_STARTED, I can remain connected to the Postcard as it goes from Rover mode into Base mode!

And I can Disconnect and Reconnect and it keeps working!

If I close the Serial Bluetooth Terminal App, turn Bluetooth off and on again
I still see Postcard Rover-A4DA in Paired Devices (not Postcard Base)

If I unpair, turn Bluetooth off and on again
I see Postcard Rover-A4DA in Available Devices (not Postcard Base)
If I pair, I can connect and open the Menu

OK. That is fascinating.
Because bluetooth does not go 'offline' in the RTK firmware, the deviceName is never updated with the Base- prefix. And it maintains the same connection.

@nseidle and I were talking about exactly this with regard to #723

Ah. Now that I look at #723 again, there is a ton of overlap with this issue...

Looking at bluetoothStop(), we don't delete the bluetoothSerialSpp/Ble/BleCommands instances. And we probably should, because we always new them again in bluetoothStart(). I suspect that is causing the memory leak discussed in this comment.

[amlago]

Hi Paul
@PaulZC
I put the Postcard in Base Mode.
Then I turned it off. I turned it on and booted into Base Mode, and then I could connect via Bluetooth.
So, if I switch to Base Mode, I lose the Bluetooth connection.
If I turn it off and on, the Bluetooth connection returns.

[PaulZC]

Hi Angel (@amlago ),

OK. Thank you. I think that agrees with my notes and observations.

I will talk to @nseidle about this later today, and we will decide on a way forward.

Thanks again,
Paul

[doug-foster]

Could you guys also ponder my suggestion for “assisted base mode” (last comment on #723) while studying a fix for #737? Maybe it could be a (mostly) easy add-in to the fix? :-)

[PaulZC]

Hi Angel (@amlago ) & Doug (@doug-foster ),

@nseidle and I discussed this yesterday. We've decided to try the breaking change of keeping the Bluetooth device name the same - in both Base and Rover mode. When we try the changes, the device will always appear as (e.g.) "Postcard-A4DA". The Base and Rover suffixes will be dropped. The big upside of this is that the Bluetooth connection will be maintained when going from Rover to Base, and vice versa. The downside is that it's a breaking change. Some users will be using the suffix to identify what mode the firmware is in; that feature goes away. All devices will (probably) need to be re-paired (but Android seems quite forgiving on this - as seen above).

Doug: I believe this change will provide the “assisted base mode” you've asked for? Please confirm... Thanks!

Angel: this will prevent your lost connection issue, and the need to power cycle the Postcard. I hope you are OK with losing the Base / Rover suffix in the Bluetooth name? Please confirm... Thanks!

If either of you - or anyone else - can think of any unexpected consequences of the change, please let us know. I haven't identified any "gotchas" yet. I don't think it will cause issues for NTRIP, for example. We will be careful to ringfence the changes, so we can revert them if needed.

All the best,
Paul

[amlago]

Hi Paul (@PaulZC)
I'm fine with keeping the same name if we eliminate connection issues.
The distinction between rover and base in the name was never a priority for me.
Actually, my phone always recognized it as Postcard-Base-xxxx even when it was in rover mode. I'd never paid much attention to the name before.
So, I'm going ahead with the changes.
Regards
Angel