mRo DualBand Wi-Fi Telemetry Radio

Created OnMarch 29, 2022

Last Updated OnMay 9, 2022

byAnastasia Zakharova

Background

Have you ever lost telemetry due to 2.4 WiFi band saturation?

We developed this radio attending our customers requests for a 5 GHz capable telemetry radio.

The mRo DualBand Wi-Fi radio is developed around the UBLOX ODIN-W260 module. It comes with a JST-SH 6 pin connector allowing you to easily integrate with existing autopilots. Supports UDP or TCP connections and can be configured as Station or Access Point.

The mRo DualBand Wi-Fi radio is NDAA compliant.

Typical Usage

The default parameters are:

WiFi mode	AP
UDP	enabled
Local port	14550
Auto reply	enabled
SSID	mRo_wifi
Password	controlZero
IP address	192.168.2.1
UART baud rate	115200
MavLink	disabled

A WiFi network will be created automatically when mRo DualBand Wi-Fi radio is powered on.

You will find a JST-SH 6 pin to JST-GH 6 pin cable included, which is the standard for our boards. Connect the mRo DualBand Wi-Fi radio’s UART port to any of your autopilot’s telemetry ports.

Your autopilot’s telemetry port should have a baud rate of 115200(115 for ArduPilot).

After powering on the radio, wait for the Status LED to turn solid green. Then connect your computer to “mRo_wifi” network using “controlZero” as password. Open Mission Planner and select UDPCI as the connection type. Enter 192.168.2.1 when asked for the host name/ip, and 14550 as the remote port.

If you use QGroundControl, add a new communication link and configure it as in the next image:

Antennas

mRo DualBand Wi-Fi radio has two antenna UFL coaxial connectors. The main antenna connector supports dual-band WiFi. The diversity antenna connector adds support for 2.4 GHz band Wi-Fi (2×2 MIMO). So, if you want to use the 2.4 GHz band, add a second antenna for better performance.

The main antenna should always be connected when the mRo DualBand Wi-Fi radio is on. See the previous diagram to identify the connectors.

AT Commands

mRo DualBand Wi-Fi radio can be configured using AT commands through Wi-Fi or UART communication.

Using WiFi

You can use any UDP client app to connect to mRo DualBand Wi-Fi radio.

For Windows users, Hercules is a good option.

For Linux and Mac users, we recommend NetCat. Use this command nc -u 192.168.2.1 14550 to establish an UDP connection.

Note that if you change any of the network parameters, you would have to make the corresponding adjustments to reach the module through Wi-Fi.

Using UART

If you want to change the default settings using the UART port, you will have to configure the mRo DualBand Wi-Fi radio before connecting the autopilot. You can use the mRo USB FTDI Serial to JST-GH to connect the mRo DualBand Wi-Fi radio to your computer.

Any serial terminal program can be used to establish communication with the mRo DualBand WiFi radio.

Windows users can use RealTerm or Hercules .

For Linux and Mac users, Cutecom is a good option.

Available commands:

Command	Action
+++++	enables AT mode
ATB	display bootloader version
ATI	display parameters values
ATH	display commands information
ATO	exit AT mode
ATSX?	display parameter X
ATSX=Y	set parameter X equal to Y
ATSH	display parameters description
AT&D	set parameters to default
AT&W	save parameters

All parameters have a numeric id used to change their values. See the following table:

ID	Name	Posible values	Description
S0	Firmware version		Can not be changed.
S1	Debug mode*	0	Debug mode disabled
S1	Debug mode*	1	Debug mode enabled
S2	WiFi mode	0	WiFi disabled
		1	Access Point
		2	Station
S3	Connection protocol	0	UDP connection
S3	Connection protocol	1	TCP connection
S4	Auto reply		Used for UDP connection only.
		0	Reply to port specified in S10.
		1	UDP server like behavior. Reply to source port of UDP packet.
S5	WiFi channel		Used in AP mode only
		1 to 11	2.4 GHz band
		36 to 64	5 GHz band
		100 to 144	5 GHz band
		149 to 177	5 GHz band
S6	DHCP		Used in station mode only
		0	Use static IP specified in S7.
		1	Get IP from the router's DHCP.
S7	Local IP		Local IP (IPV4). Used if AP mode is active or if Station mode is active and DCHP is disabled.
S8	Local port		Listening port
S9	Peer's IP		Peer's IP (IPV4). Used if UDP is active and Auto reply is disabled.
S10	Remote port		Peer's listening port. Used if UDP is active and Auto reply is disabled.
S11	Subnet mask		Used in AP mode. It is also used to recalculate peer's IP when UDP is active and Auto mode is disabled
S12	Gateway		Used in AP mode.
S13	IP Filter		Only used if UDP connection is active and Auto reply mode is disabled.
		0	Use peer's IP as it is.
		1	Use local network's prefix for peer's IP.
S14	SSID AP		mRo DualBand Wi-Fi radio network's name. Used in AP mode only. 16 characters max. This is the network you should connect your computer to.
S15	Password AP		mRo DualBand Wi-Fi radio network's password. Used in AP mode only. 16 characters max. This is the password your should use when connecting your computer (WPA2).
S16	SSID Station		Used in Station mode only. 16 characters max. This is your router network's name.
S17	Password Station		Used in Station mode only. 16 characters max. This is your router network's password(WPA2).
S18	UART baud rate		UART baud rate. 921600 max**.
S19	Module mode	0	Bridge mode
S19	Module mode	1	MavLink mode. Only MavLink messages will be forwarded.
S20	Data mode	0	Data mode disabled. ODIN module will not forward any data even if it's connected to the network. All UART messages will be handled by ODIN's command mode.***
S20	Data mode	1	Data mode enabled.

*Debug mode is only available through UART communication.

**115200 is the maximum constant baud rate with no data loss. ODIN UART communication works at 115200 baud rate.

***Disabling Data mode is only recommended if you use the mRo DualBand Wi-Fi radio as a dev board for the ODIN module.

Configuration example

Let’s say you want to connect your mRo DualBand Wi-Fi radio as a station to an already existing Wi-Fi network. You would have to send the following commands:

Command: +++++

Response: mRo AT Command mode

Command: ATS2=2

Response: mRo OK

Command: ATS16=my_ssid_name

Response: mRo OK

Command: ATS17=my_password

Response: mRo OK

Command: ATS6=1

Response: mRo OK

Command: AT&W

Response: Params flashed successfully.

mRo OK

Command: ATO

Response: mRo OK

In the next power cycle your mRo DualBand Wi-Fi radio should connect to your network. Use the IP assigned by your router to establish an UDP connection.

You can also use a static IP if you know your router’s network beforehand. Set S7 to the desired IP and S6 to 0.

Use the ATI command to check that you typed the SSID and password correctly. Otherwise you will not be able to connect to your mRo DualBand Wi-Fi radio via Wi-Fi again.

JST-SH Pinout

Pin	Signal	Volt
1 (Red)	VCC IN	5V
2 (Black)	RX	3.3V
3 (Black)	TX	3.3V
4 (Black)	RTS	3.3V
5 (Black)	CTS	3.3V
6 (Black)	GND	GND

Return to default parameters

If you changed some parameters and now you can not connect to your mRo DualBand Wi-Fi radio, you can always go back to the default parameters.

After you power on the radio and while the Status LED is still blinking, shortcut the BOOT0 square path in the back of the board with the path closest to the corner under the label of BOOT.

Do NOT do it before the Status LED start blinking. You will have a window of at least 5 seconds after you power on the radio.

If you do it right, the Status LED should stop blinking and turn solid green immediately after.

Power cycle the mRo DualBand Wi-Fi radio for the default parameters to take effect.

Update firmware

Firmware update is only possible through UART communication using the mRo Programmer Utility. It is available for Windows, MacOS and Linux.

Connect the mRo DualBand Telemetry Radio to your computer and click on the Refresh button. Select the corresponding device on the drop down list and click on Connect. The output should be similar to the following image:

Then select the binary file using the Select file button, or type the absolute path to the file if you prefer. Next click on the Update button and wait for the program to finish.

The output should be similar to the following image:

Verify that the message “Program flashed correctly!” is shown in the console.

Update ODIN's firmware

Do not update ODIN’s firmware if you do not have to. If you do it, is under your own risk.

You will have to disable WiFi mode (ATS2=0) and do a power cycle. After that, you will be able to use s-center program provided by u-blox to upload the new firmware. Select None for flow control when configuring the port in s-center.