Wireless Module (DWM)

Info Box Applies to DWM Applies to SBC Lynx Applies to ADD-ON SBC-LYNX Applies to SBC DIVA Applies to SBC AXEL Applies to ADD-ON SBC-AXEL Applies to ADD-ON SBC-DIVA

Specification

The module is built around an LS Research TiWi-BLE Integrated Transceiver Modules for WLAN 802.11 b/g/n and Bluetooth. The module implements the necessary PHY/MAC layers to support WLAN applications in conjunction with a host processor over a SDIO interface. The module also provides a Bluetooth platform through the HCI transport layer. Both WLAN and Bluetooth share the same antenna port.

Features

• Based on Texas Instruments WL1271L Transceiver
• IEEE 802.11 b,g,n,d,e,i, compliant
• Bluetooth 2.1+EDR, Power Class 1.5
• Full support for BT4.0 BLE and ANT
• Reduced footprint: 25 mm x 38 mm
• Low height profile
• U.FL connector for external antenna
• Integrated band-pass filter
• Industrial operating temperature range: -40 / +85 °C

Interface timings

Please refer to the TiWi-BLE Datasheet for SDIO [WiFi] and UART [Bluetooth] interface timings.

Pinout and detailed pin functions

DWM can be connected to the host board through the J1 connector.

Pinout reference

The following picture shows the reference pins of the J1 connector (placed on the bottom side of the DWM module):

J1 connector pinout table

The following table reports the connector pinout:

Pin number	Name	Type	Description	Voltage	Note
1	BT_EN	Input	Bluetooth Enable	3.3V
2	WIFI_EN	Input	WLAN Enable	3.3V
3	BT_CTS	Input	Bluetooth HCI UART CTS	3.3V
4	WIFI_IRQ	Output	WLAN Interrupt Request	3.3V
5	BT_RX	Input	Bluetooth HCI UART RX	3.3V
6	BT_F2	Input	Bluetooth Wakeup	3.3V	Please leave unconnected if not used
7	BT_RTS	Output	Bluetooth HCI UART RTS	3.3V
8	WIFI_CLK_REQ(A)	Output	HOST_WakeUp	3.3V	Please leave unconnected if not used
9	BT_TX	Output	Bluetooth HCI UART TX	3.3V
10	NC		Reserved for future use	-	Please leave unconnected.
11	DGND		Ground	-
12	NC		Reserved for future use	-	Please leave unconnected.
13	DAT3	Input/Output	SDIO Data Bit 3	3.3V
14	NC		Reserved for future use	-	Please leave unconnected.
15	DAT2	Input/Output	SDIO Data Bit 2	3.3V
16	NC		Reserved for future use	-	Please leave unconnected.
17	DAT1	Input/Output	SDIO Data Bit 1	3.3V
18	NC		Reserved for future use	-	Please leave unconnected.
19	DAT0	Input/Output	SDIO Data Bit 0	3.3V
20	NC		Reserved for future use	-	Please leave unconnected.
21	DGND		Ground	-
22	DGND		Ground	-
23	SDO_CMD	Input/Output	SDIO Command Line	3.3V
24	SDO_CLK	Input	SDIO Clock	3.3V
25	DGND		Ground	-
26	DGND		Ground	-
27	3.3V	Power Input	+3.3V Input Voltage	3.3V
28	3.3V	Power Input	+3.3V Input Voltage	3.3V
29	5V	Power Input	+5V Input Voltage	5V
30	5V	Power Input	+5V Input Voltage	5V

Connector part number

• on module: Molex 501920-3001
• on Carrier board: for example Molex 52991-0308 (dependon on stand-off chosen)

Antenna connector

The following picture shows the position of the WiFi/Bluetooth antenna connector:

Integration guide

This section provides useful information and resources that let the system designer integrate the DWM module in the application very quickly.

Typical scenario

The following picture shows the conceptual block diagram of the application where the host is an Embedded PC.

Typical scenario

Electrical guidelines

• Keep SDIO lines as short as possible.
• 5V and 3.3V rails can power up in any order
• Keep WIFI_EN asserted during power-up sequence

Mechanical information

The following image shows the module dimensions:

DWM dimensions

• DXF: https://www.dave.eu/system/files/area-riservata/dwm.dxf_.zip

Layout

The following images show the module layout:

DWM Top View

DWM Bottom View

The component view (top and bottom) is available as PDF file:

• PDF: https://www.dave.eu/system/files/area-riservata/CS061412B_all_view.pdf

3D

• IDF (3D): https://www.dave.eu/system/files/area-riservata/dwm-3D.zip

Calibration process

The radio interface of the DWM module is configured by several parameters. These parameters are set through a calibration process, that is described in detail here.

The calibration process—that produces an NVS file—is not trivial. Apart from the chip itself (Texas Instruments WL1271L in this case), it depends on:

• the antenna - a list of certified antennas and cables can be found in the TiWi Module device datasheet. Use of these antennas does not require additional FCC/IC/ETSI certifications.
• the firmware version downloaded to the chip: please refer to the proper firmware available on your Linux distribution for matching the kernel driver and run properly the calibration process
• the initialization data, typically stored in an INI file: please refer to the Laird Connectivity TiWi documentation for checking the proper INI file configuration
• the Calibrator source code here

More information about kernel driver and calibration on the Laird Support and Tools web page.

MAC address

The MAC address is set at calibration time for WLAN. To use the built in MAC address for WLAN be sure to pass a MAC address of 00:00:00:00:00:00 as a parameter to the auto-calibrate function. To set a custom MAC address for WLAN just pass the desired value into the auto-calibrate function.

NVS ready-to-use calibration files

The following links refer to specific use cases, where the resulting NVS file is provided along with DAVE Embedded Systems products integrating DWM module.

• SBC Lynx (XUELK)
• SBC Lynx (Debian)

The nvs.bin file has been created using the certified antenna Molex 47950-0011

Please refer to the below Laird Connectivity TiWi-BLE documentation for more information.

References

• Laird Connectivity TiWi-BLE documentation
• TiWi-BLE datasheet
• Antenna Design Guide
• EMC Compliance Guide
• WLAN INI all certified antennas
• WL127x Linux Calibrator

Since January 15, 2021, TI's processors wiki site has been shut down. The following original documentation is available only as cached pages.

• WL127x Main page
• WL127x WLAN API
• Calibration Process