BX310x Activating Legacy Pairing PIN Feature using SPP under Windows

IoT Modules
1

BX310x Activating Legacy Pairing PIN Feature using SPP under Windows

We currently have a product using legacy Bluetooth (PIN mode) pairing to
prevent unauthorized users from pairing with our device. This mode uses a
4-digit PIN.
The microcontroller on our product programs a “secret 4-digit PIN” into the
BT module, based on user input. The product presently uses a BT module from
another company, but we want to change it to the BX3105.

I am using the BX3105 DEV KIT_6001182 for to verify that the BX3105 can
perform the required functions.
I am using the following two documents to provide configuration information:
-BX310x_AT_Command_Ref r6.pdf
-AirPrime - BX310x - AT Command Reference - R7.0.pdf

I looked on your web site and did not find any examples how to configure the
product in SPP mode. I also did not find information on activating legacy
pairing PIN feature.
I did read Your list of commands. I successfully configured SPP mode.
On the Personal computers with windows 7 and 10, with 32 bit and 64 bit
processors, the BX3105 was detected, paired and assigned to a serial COM
PORT.
Terra Term found it and worked right away. PERFECT!!!
Now I am trying to activate the legacy pairing PIN feature.
I found command: “legacy pairing PIN feature”
It looks amazing, you have more options than our current module, if it
works.

THE PROBLEM:
I don’t know how to activate the "legacy pairing PIN feature ".
SRBLESECPARAMS is at its default value 3.
Any other option for SRBLESECPARAMS activates random 6-digit automatic
generation on the PC side, and I cannot use it in our product.
From Your Forum, I saw 2 discussions in which the customer asked for this
feature, but because they are not using SPP, you didn’t tell them how to
activate the legacy pairing PIN feature.
I am using SPP. It looks like the “legacy pairing PIN feature” is there.
Please help!

The text below is how I am configuring the device, based on what I
understand from your list of commands.
I am definitely missing something. Please help!
How do I activate the legacy pairing PIN feature in SPP mode under Windows?
NOTE: No support for cellphone connection is required for now!

ATI0
BX310x
OK
AT+FMR
BX310x.2.7.3
OK
AT&F
OK
Sierra Wireless Copyright 2018
BX310x.2.7.3
READY
AT+SRBTSYSTEM=0
OK
AT+RST
OK
Sierra Wireless Copyright 2018
BX310x.2.7.3
READY
AT+SRBTSYSTEM=2
OK
+SRBTC_IND: 0
AT+SRBTNAME=“MPM-BT Classic-BX3105”
OK
AT+SRBTCPROFILES=1
+SRBTC_IND: 12
OK
AT+SRBTCPINCFG=1,5867
OK
AT+SRBTCTXPWR=4,7
OK
AT+SRBTSTATE=1,2
OK
+SRBTPAIR: “e8:4e:06:7f:c7:17”,1
AT+SRBTCSECPARAMS?
+SRBTCSECPARAMS: 3
OK

Eng. Milen Moussakov

2

@milenm

So if you are trying to do this with Windows it will almost certainly be BT classic and not BLE.

Regards

Matt

3

Hi Matt,

I do not understand your message ?!?!?

How to activate the functionality?

Please Help!

In the datsheet are 3 pages with commands and examples, with this functions working.

How to do it? How to enable it?

How You did it when you wrote the list of commands manual?

Plese help!

Eng. Milen Moussakov

4

@milenm

Typically when examples are given it will be between two BX devices, as a rule we will not use a 3rd party device like a handset or windows PC.

Did a bit of testing and if you run the commands as above but then set the command as below

AT+SRBTCSECPARAMS=1
OK
+SRBTCSECNUMCMP: “28:16:ad:8a:80:4e”,605642

Then Windows will then ask you to confirm the PIN is the same across the devices (so Windows was showing 605642 for the above). I did have an issue with it actually completing the pairing procedure but this will trigger what you want it to. If it is set to 3 then it does ‘just work’ given you are telling the unit that what it is connecting to does not have a display or a keyboard to be able to do the confirmation.

Regards

Matt