Short introduction to the board

PCB
The board is based on a popular form factor called “Feather” which is created and maintained by an American company called Adafruit. The entire specification for the Feather format is available here. The size of the PCB for the module is 50.80mm x 22.86mm but the entire module is a little bit bigger as the Type C USB connector protrudes about 1 mm outside the board and on this particular board the antenna of the radio module also stick out about 4.4mm’s on the other side of the board.

UWB Module

The DWM3000 is an ultra-wideband (UWB) transceiver module developed by Qorvo Inc. It operates in the frequency range of 3.1 GHz to 10.6 GHz and has a maximum output power of 4 dBm. The module uses the IEEE 802.15.4a standard for UWB communication, which enables highly accurate ranging and positioning with an accuracy of up to 10 cm.

The DWM3000 module integrates a Qorvo DW3110 chip, which provides UWB communication capabilities. The module measures 21mm x 16mm x 2.5mm and has a power consumption of approximately 75mA during active mode and 1.5μA during sleep mode. It supports SPI and UART(Not supported on the Challenger board) interfaces for communication with external devices and has a built-in antenna for wireless communication.

The DWM3000 is designed for use in a variety of indoor positioning and communication applications, such as asset tracking, inventory management, and personnel tracking. It also features a small form factor and low power consumption, making it suitable for battery-powered devices.

Overall, the DWM3000 is a highly accurate UWB transceiver module designed for indoor positioning and communication applications that require high precision and low power consumption.

It is IEEE 802.15.4a and IEEE 802.15.4z BPRF mode compliant and allows location of objects to a precision of 10 cm. The module has worldwide UWB support through its operation on UWB channel 5 (6.5 GHz) and channel 9 (8 GHz). The module is also interoperable with the Apple U1 chip and is designed to be compliant to the FiRa™ PHY and MAC specifications enabling interoperability with other FiRa™ compliant devices.

Here’s a simple table with a few of the highlights of the module listed:

• Link to DWM3000 datasheet.
• Link to DWM3000 Schematic.
• Link to Qorvo Documentation page.

Link

Headers
On each of the longer sides of the PCB there are holes intended for soldering pin header connectors. If you don’t want to use connectors for some reason you can also solder a wire directly into the hole, making a permanent connection to your external device. If you go this way please make sure that the wires are fixed in place, otherwise vibrations can cause the wire to brake at the soldering point.

LED’s
On each side of the USB connector there is a small indicator LED placed. The LED which is marked CHG is the charge control indicator. This red LED will shine whenever the connected battery is being charged, and when the battery is fully charged the LED will turn off again. If you haven’t connected a battery to the board this LED will not come on at all.

On the other side of the USB connector there is a user programmable green LED. This LED is connected to pin D18 (BUILTIN_LED) and can easily be controlled by the user program.

Hardware details

External pins

The on board micro controller (RP2040) have a number of communication channels that have been routed out to the side (header connector) connectors.

• UART – One UART (UART1) channel have been routed to the header pins (RX, TX).
• SPI – One SPI (SPI1) channel have been routed to the header pins (SCK, SDO, SDI).
• I2C – One I2C (WIRE1) channel have been routed to the header pins (SCL, SDA).
• Analog pins – The micro controller have 4 analog input pins that all are available on the header pins (A0-A3).
• PWM – All pins can be used for PWM.

The pin chart below shows the placement of all pins and their respective functions. When working in an Arduino environment (or Platform IO) use the blue pins when writing your code and when working with CircuitPython use the orange marked pin assignments.

Power

The board can be powered from multiple sources. The most obvious way to run the board is by plugging it in to a USB cable and attach it to your computer. In this mode you can write software and test the board with all its functionality.

There is also a third way to supply the board. This way is more invasive and will disable the onboard 3.3V power regulator.

You will have to pull the EN header pin low and then supply your own 3.3V voltage on the 3.3V header pin. Please note that when disabling the onboard power regulator you will have to supply the 3.3V also when running the system on battery power.

Battery

As described earlier the board can be powered from a LiPo battery. The battery can be connected using a standard 2.0mm JST connector through the battery connector on the right side of the board or ff the battery is an integral part of the system that you are designing it is possible to connect the battery through the BAT pin instead.

Switching between the battery voltage and the applied USB voltage or external 5V is done seamlessly by the on board circuitry.

Charging of the battery is done by either connecting a USB cable or by connecting a 5V power source to the header pin marked USB on the board. If you do this make sure you connect your voltage through a 1A schottky diode to avoid any excessive current draw in the system when the two levels are slightly different.

Please note that providing external charger circuitry could destroy the internal charger on the Challenger board.

DWM3000 module

Connection between MCU and the DWM3000.

The processor connects to the SD card via the second spi (SPI1) communication channel.

SPI1 Pin usage (Arduino pin names within parenthesis):

• GPIO10 is the serial clock (PIN_SPI1_SCK)
• GPIO12 is the serial data input (PIN_SPI1_MISO)
• GPIO11 is the serial data output (PIN_SPI1_MOSI)
• GPIO9 is the DWM3000 chip select signal (DWM3000_SS)

In addition to the SPI bus signals, a reset, a interrupt and a wakeup signal is also connected to the module, these are mapped to the pins as follows:

• GPIO13 – RESET. This signal is used to reset the module and is an active low signal (D14 or DWM3000_RST).
• GPIO14 – IRQ. This is the interrupt signal from the DWM3000 module to the RP2040 (D15 or DWM3000_IRQ).
• GPIO15 – WAKEUP. This signal can be used to place the DWM3000 module in sleep mode. This signal needs to be high (=1) to enable the module (D15 or DWM3000_WAKEUP).

Note to Arduino users: The support library takes care of all the necessary configuration so you really don’t need to worry about the pins.

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