BU03-Kit Development Board (Hardware Section 1)

——AndyL

1. Hardware Overview

1.1 About BU03-Kit

The BU03-Kit is a UWB development board based on the BU03 (DW3000) module and powered by an STM32F103C8T6 MCU. The BU03 module integrates an onboard antenna, RF circuitry, and power management.

It supports Two-Way Ranging (TWR) and Time Difference of Arrival (TDOA) positioning with up to 10 cm accuracy and a maximum data rate of 6.8 Mbps. Applications include IoT, mobile devices, wearables, and smart home solutions.

 

1.2 Key Features of BU03

  • SMD-40 pin package
  • Compliant with IEEE 802.15.4-2015 UWB and 802.15.4z (BPRF mode) standards
  • Supports channels 5 and 9
  • Integrated MAC layer for extended communication range
  • Data rates: 850 Kbps and 6.8 Mbps
  • Supports TWR, TDOA, and PDOA positioning
  • 10 cm positioning accuracy
  • High tag density support
  • Integrated hardware AES 256 encryption
  • SPI interface and 9 configurable GPIOs
  • Programmable transmit power
  • Sleep mode current <1 µA, ideal for coin cell battery solutions
  • High-precision positioning
  • Strong security
  • Low interference with other communication technologies
  • Low power consumption

 

Typical Power Consumption (@3.3V, 25°C):

Mode

Average Current (mA)

CH5 TX @ 0.85 Mbps

17.03

CH5 TX @ 6.8 Mbps

15.06

CH9 TX @ 0.85 Mbps

24.85

CH9 TX @ 6.8 Mbps

22.6

CH5 RX @ 0.85 Mbps

39.81

CH5 RX @ 6.8 Mbps

40.01

CH9 RX @ 0.85 Mbps

49.23

CH9 RX @ 6.8 Mbps

48.05

Instantaneous Startup Current

174 mA

Deep Sleep Current

179 nA

 

1.3 Pin Definitions

Pin

Name

Description

1

EXTON

External device enable during wake-up; used to minimize power consumption.

2

WAKEUP

Brings DW3000 from sleep/deep sleep to active mode. Tie to GND if unused.

3

RSTN

Reset pin, active low; equivalent to power cycle reset.

4

IO7

GPIO7 / SYNC input; reconfigurable if SYNC not used.

5

VDD

Power input (1.8V–3.6V), ≥200mA recommended.

6-7

VCC

Power input (2.5V–3.6V), ≥200mA recommended.

8

GND

Ground.

9

IO6

GPIO6 / SPIPHA / EXTRXE; SPI phase select or external RX enable.

10

IO5

GPIO5 / SPIPOL / EXTTXE; SPI polarity select or external TX enable.

11

IO4

GPIO4 / EXTPA; external power amplifier enable.

12

IO3

GPIO3 / TXLED; drive LED after transmission.

13

IO2

GPIO2 / RXLED; drive LED during reception.

14

IO1

GPIO1 / SFDLED; LED indicator when SFD (start frame delimiter) is detected.

15

IO0

GPIO0 / RXOKLED; LED indicator for successful frame reception.

16

GND

Ground.

17

CSN

SPI chip select (SPICSn); also used for waking from sleep modes.

18

MOSI

SPI data input.

19

MISO

SPI data output.

20

CLK

SPI clock input.

21

NC

Not connected.

22

IRQ

GPIO8 / IRQ output; active high by default; reconfigurable.

23

NC

Not connected.

24

GND

Ground.

Note : All GPIOs except SPICSn have internal pull-down resistors. SPICSn has an internal pull-up for safe operation when un-driven. Resistance varies with VDD (10kΩ at 1.8V to 30kΩ).

2. About the BU03 Module

The BU03 is an ultra-wideband (UWB) module based on Decawave’s DW3000 chip.

2.1 What is UWB?

Ultra-Wideband (UWB) is a wireless technology that transmits data via very short pulses instead of traditional carriers. The shorter the pulse in the time domain, the wider its bandwidth in the frequency domain — often reaching GHz levels.

Key advantages of UWB:

UWB systems typically follow the IEEE 802.15.4z standard, using Impulse Radio techniques.

 

2.2 UWB Positioning Methods

Distance-based methods:

  • TOA (Time of Arrival): Measures the signal’s travel time to compute distance; requires synchronization among devices.
  • TWR (Two-Way Ranging):
    • SS-TWR (Single-Sided): One device measures the round-trip time; requires clock sync.
    • DS-TWR (Double-Sided): Both devices measure and exchange timing information; compensates...
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