In order to maximise range DW1000 transmit power spectral density (PSD) should be set to the maximum allowable for the geographic region. For most regions this is -41.3 dBm/MHz. The DW1000 provides the facility to adjust the spectral bandwidth and transmit power in coarse and fine steps.
See for further details APS023 Transmit Power Calibration & Management available from our website: http://www.decawave.com/support
For software developers and firmware engineers to debug their software we have an application note. This application note describes step by step debugging of the applications and drivers which control the DW1000.
See APS022 Debugging DW1000 based products systems on our website: http://www.decawave.com/support
The DW1000 chip provides a complete PHY layer but does not implement a full MAC, although it does provide some MAC features such as address filtering. In the context of RTLS tags you should carefully consider the necessity for a MAC scheme because these generally require each node to listen for synchronizing broadcasts of some kind. This increases power consumption and reduces battery life.
For more information see the DW1000 IC user manual Chapter 5 “Media Access Control (MAC) Hardware Features” which is available from http://www.decawave.com/support#term5
Processor requirements are highly dependent on the end application.
For a Two-Way ranging (TWR) mobile tag a microprocessor with at least 16k of flash and 4k of RAM should be used to run Decawave’s TWR demo application.
For TDoA based mobile tag application, a smaller microprocessor e.g. with 4-8k of flash and 1-2k RAM may be used.
If you want to minimize system power consumption we recommend using a microprocessor with a fast start-up time and an SPI interface capable of the maximum 20 MHz rate supported by the DW1000.
The example EVK and TREK application software source code is built on the ARM Cortex M3 based microcontroller (STM32F105RCT6) which is a 32-bit, little-endian processor. Areas to be considered when using an 8-bit microcontroller are described in Application Note: “APS019 Driving DW1000 from 8-bit MCU v1.0” available on http://www.decawave.com/support#term5.
As the package is an industry standard 48 pin QFN 6 x 6 mm with 0.4 mm pitch and exposed ground paddle, we refer customers to JEDEC specification J-STD- 020.1 (March 2008).
This specification is available from the following link: http://www.jedec.org/standards-documents/ PCB land-pattern libraries are available for 3 common CAD packages on the Decawave website.
To assist customers with PCB layout of a DW1000 based product, files in DXF format are available on www.decwave.com. These DXF files can be imported into most PCB layout EDA tools and used as an overlay to replicate the DW1000 section of Decawave’s EVB1000 evaluation boards.
Please refer to application note “APH006 PCB Layout” available on http://www.decawave.com/support#term5
Decawave and the IEEE 802.15.4a standard specify +/-20ppm crystals. Other crystals meeting this specification should also work provided the guidelines in the DW1000 datasheet are followed. Alternate crystals should of course be tested before committing to a design.
We have an application note which explains the different design considerations to take care of, to maximise communications range.
See APS017 max range in DW1000 systems available from our website: http://www.decawave.com/support
Yes, we provide an abstracted view of the DW1000 register set to the software programmer. This API includes a set of examples demonstrating how to use the API to perform some of the most commonly required operations.
This API and the software source code can be downloaded from: http://www.decawave.com/support/software