Bluetooth Bluno M3 to HC-05 connection

Hi team,

I need some help getting some Bluetooth connections working.

I have not been able to make a bluetooth connection between a Bluno M3 (v2.2) board and a HC-05 Bluetooth module.

In attempting to get a working solution, I have attempted but have been unable to get a Bluno to pair with another Bluno or a Bluno to pair with any of the HC-05 cards.

This is what I have been able to achieve.

  1. I can enter AT mode on all devices.

  2. I have been able to set up the respective CMODE, UART and ROLE for both devices and for the Master, save the BIND address in the master for the respective SLAVE device.

  3. I have been able to uniquely pair the two HC-05 to each other (one running off a MEGA and the other off a Uno board). In fact, I used this configuration to swap out the HC-05 slave insert a slave Bluno but this was unsuccessful.

  4. I have been able to scan for, pair and connect a Bluno to my iPhone using the DFRobot Play BLUno app and subsequently send data from the iPhone to the Bluno M3 (2.2) which is seen on the serial monitor.

This confirms each device is able to be paired and linked in one form or another. Despite my searching copious amounts of on-line information starting here DFRobot wiki and trying various modes of connection e.g. any/unique/specific and swapping roles, I have not been able to get the Bluno to connect to a HC-05 (which is the required outcome).

Has anyone achieved such an outcome and if so, what steps/procedure were used to make the connection. I would be grateful if anyone with the same hardware could try to establish a connection and if successful, share the process with me.



Hey @Tim62515,

Thanks for your post. From a quick google I was able to find this. DFRobot have said that the Bluno will only be supported by other DFRobot Bluetooth modules.

I hope this helps.

Wow, great work Gordon, finding this post. I looked at many of these threads on this same site and am embarrassed to say, I didn’t find this particular post :frowning:

How disappointing to get this news. Would you not have though that this particular limitation would have been a little more overtly displayed with the marketing material from the manufacture (rhetorical question) . While in my case it’s a secondary requirement, (I need the Bluno to talk to HC-05) I can’t even get the Bluno to connect to another Bluno, go figure !!! I will instead now use my Bluno to pack the gap in my uneven bookshelf. Let’s hope it can do that without playing up and disappointing me further.

Thanks again for the info.


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