# BC127 firmware upgrade tool UART protocol

**URL:** <https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874>\
**Category:** WiFi and Bluetooth Modules\
**Created:** [October 19, 2023, 5:38am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874 "2023-10-19T05:38:21Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![nir76](https://avatars.discourse-cdn.com/v4/letter/n/ecb155/32.png) [@nir76](https://forum.sierrawireless.com/u/nir76)\
**Post date:** [October 19, 2023, 5:38am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/1 "2023-10-19T05:38:21Z")

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Hello all,  
My BC127 in connected via UART interface to a local host, this host is also connected to “outside world” via USB2.0.  
I wish to perform firmware upgrade using firmware upgrade tool, through the host USB virtual com port.  
In other words, I need that the firmware upgrade tool can be connected to the BC127 via UART \> MCU \> USB \> laptop + upgrade tool  
Can someone from the support team send me the protocol between the BC127 and the upgrade tool?  
Best regards,  
Nir

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [October 20, 2023, 10:10am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/2 "2023-10-20T10:10:42Z")

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Hi @nir76,

Based on your description, you’re currently using the BC127 with a custom board, is that correct?  
Do you have a BC127 Discovery Board? If yes, please use the Melody DFU (Device Firmware Upgrade Tool) to update the firmware for the BC127.  
Please refer to the ‘Setting up’ section on page 10 of the BC127 Melody Audio 7.x User Guide and the firmware update instructions at the following links:

[https://source.sierrawireless.com/resources/airprime/hardware\_specs\_user\_guides/bc127-melody-audio-7-user-guide/#sthash.RUtkFGXz.dpbs](https://source.sierrawireless.com/resources/airprime/hardware_specs_user_guides/bc127-melody-audio-7-user-guide/#sthash.RUtkFGXz.dpbs)  
[https://source.sierrawireless.com/resources/airprime/software/bc127-firmware-upgrade-tool/#sthash.NKUFepoR.dpbs](https://source.sierrawireless.com/resources/airprime/software/bc127-firmware-upgrade-tool/#sthash.NKUFepoR.dpbs)

Thanks,

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**Author:** ![nir76](https://avatars.discourse-cdn.com/v4/letter/n/ecb155/32.png) [@nir76](https://forum.sierrawireless.com/u/nir76)\
**Post date:** [October 22, 2023, 4:20am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/3 "2023-10-22T04:20:39Z")

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Hi,  
The final goal is to design a custom board. I do have an evaluation board but I use it only for development.  
Can you please assist?  
Best regards,  
Nir

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [October 23, 2023, 10:52am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/4 "2023-10-23T10:52:00Z")

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Hi @nir76,

Please refer to the BC127 Discovery Kit Schematics and BC127 Development Board Schematics at the following link to see if they can be of any assistance to you: [https://source.sierrawireless.com/resources//#tags=BC127|Hardware+Reference+Documents](https://source.sierrawireless.com/resources//#tags=BC127%7CHardware+Reference+Documents)

Thanks,

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<div class="post-metadata">

**Author:** ![nir76](https://avatars.discourse-cdn.com/v4/letter/n/ecb155/32.png) [@nir76](https://forum.sierrawireless.com/u/nir76)\
**Post date:** [October 23, 2023, 12:34pm UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/5 "2023-10-23T12:34:44Z")

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Hi,  
There is no information regarding Melody DFU protocol in the above link.  
Are you sierra employee? do you have access to the required information?  
Regards,  
Nir

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [October 24, 2023, 10:48am UTC](https://forum.sierrawireless.com/t/bc127-firmware-upgrade-tool-uart-protocol/30874/6 "2023-10-24T10:48:16Z")

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Hi @nir76,

In the BC127 Melody Audio 7.x User Guide, it states that Melody supports firmware upgrades over the UART interface.  
If you want more in-depth technical details, please send an email to technical support at [support@sierrawireless.com](mailto:support@sierrawireless.com)

Thanks,