How To Use MDBT50Q Demo Board (MDBT50Q-DB)

Here provides an easy introduction of How to set up of nRF52840 Module Demo board MDBT50Q-DB-40!
MDBT50Q-DB-40, built by Raytac’s MDBT50Q-1MV2  deployed nRF52840 SoC with Bluetooth 5 & Thread Combo module Demo Board. Equipped Raytac’s MDBT50Q-1MV2  with 1MB Flash Memory and 256KB RAM and Chip Antenna. Certifications include:  FCC, IC, CE, Telec, KC, SRRC, RCM, NCC, WPC
mdbt50q demo board package 拷貝

Hardware Set Up
MDBT50Q-DB-40 package contains:
  • 1 x MDBT50Q-DB
  • 1 x IDC Wire
  • 1 x Data/Power Mini USB Wire

Where to buy MDBT50Q-DB? (Please Click Me)
nRF51, nRF52 or nRF52840 DK Connects with MDBT50Q-DB-40 by IDC wire. Powered up the MDBT50Q-DB-40 by Micro USB wire.


MDBT50Q-DB Schematic

MDBT50Q Demo Board Schematic-V2.jpg
MDBT50Q-DB Schematic

Firmware Set Up Resource
Download nRF Connect For Desktop (Please Click Me)
Download nRF5 Command Line Tools (Please Click Me)
Download nRF5 SDK (Please Click Me)

Firmware Development
1. Download SDK
2. Unzip SDK
3. Use S140 Softdevice Softdevice (\nRF5_SDK_15.2.0_9412b96\components\softdevice\s140\hex\

For more detail about the Firmware development, please refer to another article for more detail:

Bluetooth Project: How to get your firmware development started

Firmware Program Steps
1. Selecting Programmer in nRF Connect

2. Selecting Program Device (refer to Nordic DK)

3. Adding Hex File
nrfconnect_protrammer_mail_screen 拷貝

4. Erase and Write

Note: If MDBT50Q-DB is powered by computer, it may detect USB connection. Pls click “No” to proceed and complete the firmware program.

nRF52840 provides USB interface which enable to support Device Firmware Update (DFU) through USB directly.
Hardware Setup
1. Press Switch 4 and Hold
2. Power in the Demo Board
3. Blue LED stays light
4. Demo Board successfully enter USB DFU Mode
Firmware Setup

  • USB DFU works in DOS mode only.
  • USB DFU only works with previous loaded firmware employs USB Bootloader feature only.
  • A single, merged hex file is required. Need to combine Bootloader, Softdevice, and Application.
  • Firmware DFU requests a zipped file.

USB Firmware DFU Steps:
1. When MDBT50Q-DB Blue LED Stays Light (shows ready to enter USB DFU Mode)
2. Find out the Com Port No. changed from “nRF52 USB CDC BLE Demo(COMxx)” tonRF52“SDFU USB(COMxx)”

3. Proceed the USB DFU
Enter DOS mode and select the file with the code in below
nrfutil dfu usb_serial -pkg -p COMxx

( refer to the code to update)
(xx refer to Com Port No.)
4. USB DFU Completed


1. Bootloader example Code can be found: 
Need to produce “micro_ecc_lib_nrf52.lib” and “public key” for latter development

2. How to merger the firmware 

  • Produce: bootloader_settings.hex

nrfutil.exe settings generate –family NRF52840 –application usbd_ble_uart.
hex –application-version 3 –bootloader-version 2 –bl-settings-version 1

  • Merge bootloader 及bootloader settings file:

mergehex.exe -m Bootloader.hex bootloader_settings.hex  -o output_1.hex

  • Merge bootloader 、bootloader settings及softdevice:

mergehex.exe -m output_1.hex s140_nrf52_6.1.0_softdevice.hex  -o

  • Merge the merged bootloader 、bootloader settings、softdevice及application:

mergehex.exe -m output_2.hex application.hex  -o usbd_ble_uart_sd_bt_app.hex

3. Zip the firmware
nrfutil pkg generate –hw-version 52 –sd-req 0xae –application-version
0xFF –application usbd_ble_uart.hex –key-file dfu.pem

Raytac Corporation 勁達國際電子有限公司
A BT5 & BT 4.2 & BTv4.1 module maker based on Nordic nRF51 & nRF52 solution
(nRF51822 & nRF51422 & nRF52832 & nRF52810 & nRF52840) email: Tel: +886.2.3234.0208

About the Author Raytac Corporation

Raytac Corporation, A Bluetooth Module Maker based on Nordic nRF52840 & nRF52832 & nRF51822 & nRF52810 Solution. Bluetooth Specification Version: BT5 & BT4.2 & BT4.1 & BT4.0 Website: Mail: Tel: +886.2.3234.0208

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