BM71 Firmware Update

Last modified by Microchip on 2023/11/09 09:03


This lab takes you step-by-step through the process of updating the firmware on the BM71 module. New firmware can add Bluetooth® Low Energy (BLE)-specific functionality for new revisions of the Bluetooth specification as well as provide a way to fix bugs discovered in the current device Bluetooth operation.

Contact your local Microchip Sales office to obtain BM71 firmware package updates.

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Reference Materials

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Connection Diagram

Connection Diagram

The Universal Asynchronous Receiver Transmitter (UART) RX and TX lines are used to communicate between the host MCU and the BM70.

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Be sure to install the MCP2200 USB drivers before starting. Also, extract the BM71 firmware package files to your computer.

The first thing we will do is check which firmware version we currently have on the module.

Connect to BM71

Connect the BM71 PICtail to your PC via the USB connector (bottom-side of the board) using the supplied USB cable. Ensure the jumpers J3, JP8, and J1 (all yellow in this photo) are set as shown:

BM71 PICtail  connected to PC via the USB connector (bottom-side of the board)

COM Port

Open the Device Manager window by going to the Start Menu > Control Panel > Hardware and Sound and then selecting Device Manager. Once open, check which COM Port has been assigned to the BM71 PICtail board. In this case, it is COM18, please note that yours will probably be different.

Device Manager showing which COM Port has been assigned to the BM71 PICtail board

Place the module in Test mode by setting SW7 in the ON position, then press SW5 (reset) to reset the module.

Module in Test mode by setting SW7 in the ON position and pressing SW5 (reset)

The module's basic operating mode (Test/Application) is sampled and established on a module reset condition. We recommend pressing the Reset (SW5) push button whenever SW7 is first changed, or when you want to be sure that SW7 is sampled and applied by the module.

With jumper JP8 shorted, LED0 will be lit (BLUE) indicating the module is in Test mode, as shown in the accompanying image.

Launch the ISupdate Programming Utility and select the correct COM port (from substep a). Set the baud rate to 115200 and the memory type to Flash/Embedded. Then click Connect.

ISSC isupdate Firmware Update tool window Access Port pane

If the connection was successful, you will see the following message:

ISSC isupdate Firmware Update tool window Port connect message

Verify Current Firmware Version

To find the currently installed version, under the Flash/EEPRom/MCU/AHB Accesss section, enter "100e" in the Address field and "2" in the Length(Hex) field. Then, click Read.

ISSC isupdate Firmware Update tool window Flash/EEPRom/MCU/AHB Accesss section

In this case, we can see that version 1.03 is installed.

Isupdate Tool displays version after Read selected

Update Firmware

Click on the Browse button and navigate to the folder where you extracted the BM71 Firmware Package earlier. Select all the needed HEX files in the dialog box and click Open.

Browse to extracted files and select Open

Click on Update.

Select Updatea button in Isupdate Tool

After a few seconds, the update will be complete and you will see a screen as seen in the accompanying figure.

ISSC isupdate Firmware Update tool window Complete message

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You can verify that you have the new firmware version by clicking Read under the Flash/EEPRom/MCU/AHB Access pane again.

ISSC isupdate Firmware Update tool window firmware verification

Lastly, you can click Disconnect and close the ISupdate tool.

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