HCI_UART protocol for download and recovery mode with BCM20736S

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Anonymous
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Hello there,

I'm working on a consumer hardware that will use the BCM20736S SiP for Bluetooth LE/Smart connectivity. Estimated annually sold units are 150k for this project and 1.2m for the next one, that's more budgetary.

The hardware consists of a fast main MCU that does the number crunching and controls the remaining hardware and is interfaced via P_UART and HCI_UART to the SiP.

For manufacturing we'll have to use pogo pins on the HCI_UART and the supplied chipload utility. We'd prefer to program it with the main MCU as this would ease the process.

The end customer will have the ability to update both the firmware via Bluetooth LE. For this purpose we'd like to first update the MCU's firmware and after successfully doing so let the MCU update the BLE module. We are pretty space constrained, so implementing OTA and UART update into our software on the BLE module isn't an option.

For this purpose we need the UART protocol the BLE module's bootloader is using. Sadly it's not documented nor are the sources of chipload and HEX loader file available.

If we have to sign an NDA we'll do it, as it will speed up development tremendously.

Please provide us with the source files or a person at Broadcom to contact.

Thank you in advance!

Best regards

Hannes Baumgart

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1 Solution
MichaelF_56
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Unfortunately, we cannot provide the source code for the minidriver (the brains behind the programming process) or the programming protocol for you to use on your external MCU.  This has been asked many times in the past and the only tools we can provide for production programming include the SDK and the command line chipload/loader tool you already mentioned.

I understand this is not ideal, but it is all we can offer today.

Note that once initial programming is done, subsequent programming/updates can occur either OTA or using the PUART (sample apps in the SDK for both).

david_armour

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2 Replies
MichaelF_56
Moderator
Moderator
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250 sign-ins 25 comments on blog 10 comments on blog

Unfortunately, we cannot provide the source code for the minidriver (the brains behind the programming process) or the programming protocol for you to use on your external MCU.  This has been asked many times in the past and the only tools we can provide for production programming include the SDK and the command line chipload/loader tool you already mentioned.

I understand this is not ideal, but it is all we can offer today.

Note that once initial programming is done, subsequent programming/updates can occur either OTA or using the PUART (sample apps in the SDK for both).

david_armour

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Anonymous
Not applicable

Hello David,

thanks for your reply.

I don't understand the motives of Broadcom for not providing the source code even with a signed NDA, but I have to accept this. Frankly it's quite a drawback of your product but we'll work around it.

Best regards

Hannes Baumgart

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