User Manual

SARK-110-ULM User’s Manual

Rev 1.0 June 22

Appendix C: Bluetooth tool firmware

The Bluetooth tool firmware, SARK110ULM_BTOOL.dfu, allows the user to perform firmware

updates of the internal RN4871 Bluetooth Low Energy module. This is not expected that the user

will need to update the module’s firmware, but this function is provided in provision of any

required future updates.

This tool also enables the user to experiment with the RN4871 module, offering part of the

functionality available in the RN4870/71 PICtail

daughter board. The SARK-110-ULM is

connected to a host computer that supports USB CDC virtual COM (serial) ports. Simple ASCII

commands can be set to the RN4871 module by using a terminal emulator program.

The Bluetooth tool firmware works as a USB passthrough to the module’s serial port. It can be

configured in “Programming mode” to perform the firmware updates or in “Normal mode” for

sending the ASCII commands. The mode must be set during the firmware startup and it can be

changed by pressing the button Setup [ ].

Setup

Follow the firmware upgrade instructions described in Appendix B: for installing

SARK110ULM_BTOOL.dfu firmware. Before installing it, ensure that the normal firmware is

installed in the internal drive, so you can switch back to it later.

➢ Notice that the tool firmware does not support the USB mass storage function, so the

internal drive will not be accessible when running this firmware -but it will be accessible

from the Device Firmware Upgrade mode.

Install the following software in your computer:

1. STM32 Virtual COM Port Driver from STMicroelectronics.

2. IsUpdate from Microchip, if you need to update the module firmware and the firmware

images.

3. Terminal emulation software such as TeraTerm, if you need to experiment with the

module. Configure the serial port settings using the enumerated COM port as shown

below.