BC127 downgrade firmware

I have an existing prototype that we have been using over the past couple years, and I am having a problem with the newest batch of BC127 modules I received. They were shipped with version V6.1.5 of the firmware (all our other units have V6.0.33 of the firmware). They are not functioning the same as the units with the older firmware, and we would like to downgrade to the older version, for various reasons. I have Melody Upgrade Tool v3.0.4.0. This app has always worked in the past with upgrading firmware. It will not complete the firmware upgrade with the latest chips, and always gives an Error 88 message. I am definitely connected and communicating over the serial interface, but unable to update. Again, this same setup and procedure is followed with older BC127 chips and the update is successful. Some help would be appreciated. Thanks.

Is there anybody out there? How can I get in touch with someone for technical service?

Yeah, since Sierra took over Blue Creation… looks like support is now a black hole.
I have used 6.0.33 through the present 6.1.3 release (I found 6.1.3 more reliable than 6.1.5 for streaming high bandwidth).

BlueCreation made subtle changes to the protocol and the serial port (sadly I forget the details).
The good news is that the 4.1.0 updater can handle going up and going backward. The older code loader doesn’t work with the 6.1.X firmware but I found that 4.1.0 loader deals nicely going backward.

The trick will be finding the 4.1.0 loader. Ping this forum again if you can’t locate it and we’ll find a way to exchange the loader. (I’m hoping Sierra wakes up soon because I am starting to design them out of products).


The protocol has not really been changed by Sierra/BC but the loader tool has obviously been upgraded/changed in the past to cater for various changes external to the protocol.

I have written how to up/downgrade the BC127 a few times on the forum but you can use the DFU wizard which is a available through the CSR support site at the below link, you obviously need to create yourself a login first.


So the procedure to downgrade once you have tool is as follows.

  1. Power the BC127 and open a serial port to it.
  2. Send the DFU command to it to get it into the right mode.
  3. Run the DFU wizard tool and follow the steps through.

Re support, Sierra policy is to support through the commercial channels i.e. you go through your distributor, assuming they are an official one then they should have received some training or at least be able to raise direct tickets with their apps engineer to get it answered. The forum/open community is done on a best effort basis (the best effort is trying to be improved).