Firmware Update for the BM70 Bluetooth® Low Energy (BLE) Module

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 BM70 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 BM70 firmware package updates.

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 BM70 Firmware Package.

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

Connect the BM70 PICtail to your PC. Ensure the jumpers are set as shown.

BM70 PICtail connected to a PC

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 BM70 PICtail. In this case, it is COM18. Please note that yours will probably be different.

Device Manager Dialog

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

BM70 module in Test mode

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 above.

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

ISupdate Programming Utility

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

Connection was successful message

Verify the current firmware version.

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

Currently installed version, under the Flash/EEPRom/MCU/AHB Accesss pane

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

Version 1.03 is installed

Update the firmware.

Click on the Browse button and navigate to the folder where you extracted the BM70 Firmware Package earlier. Select all the needed HEX files in the dialog box and click Open.

HEX files shown in dialog box

Click the Update button.

Update button

After a few seconds, the update will be complete and you will see a screen like this:

Progress bar and messages shows update complete

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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.

Flash/EEPRom/MCU/AHB Access pane

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

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