Practical evaluation guide for u-blox Wi-Fi modules running on i.MX8 Linux - Driver installation, iperf3 throughput, and RF evaluation using labtool and a spectrum analyzer -

The firmware for the u-blox module is in lib/firmware!

The lib/firmware directory contains the Wi-Fi and Bluetooth firmware for the u-blox module JODY-W3.
These are loaded into the u-blox module with the modprobe command.
The firmware is divided into two parts: one for Wi-Fi + Bluetooth for normal operation and one for RF test tools.
Furthermore, they are divided into those for Wi-Fi, those for Bluetooth, and those for Wi-Fi/Bluetooth combo.

The u-blox module driver is in lib/modules/<kernel version name>!

The /lib/modules/<kernel version name> directory contains the Wi-Fi/Bluetooth drivers for JODY-W3.
Load it with the modprobe command and include it in the system.

Tools and utilities for u-blox modules are in /opt/jody-w3!

The /opt/jody-w3 directory contains the tools and utilities required to evaluate and control the JODY-W3 module.
The configuration is broadly divided into two parts: an RF test tool package and a group of Wi-Fi utilities.
The RF test tools package includes mfgbridge and labtool for RF measurements and various tests.

The Wi-Fi utilities suite includes mlanutl, uaputl, and wifidirectutl, which allow you to control features such as client mode, AP mode, and Wi-Fi Direct.

Installed applications and tools are in /usr/!

The /usr/ directory is the standard directory for storing user-facing applications, tools, and configuration files on Linux systems.
When using JODY-W3, network-related tools, wireless LAN control utilities, and command line tools are placed in the /usr/ directory.
/usr/bin/ contains commands and applications for general users (e.g. iperf3).
The /usr/sbin/ directory contains network management tools and services for system administrators (e.g., NetworkManager, hostapd, wpa_supplicant).

Load the Wi-Fi driver with modprobe and check the device recognition log with dmesg

Before showing command examples, the debug environment for the i.MX8 evaluation board via SSH connection is shown below.

For detailed instructions on how to set up the debugging environment, please refer to the following steps in the Nexty Electronics related technology column.

• How to debug the i.MX8 evaluation board: Using USB serial connection and Ethernet SSH

The following steps are explained from the state where you have logged in via SSH after starting up the i.MX8 evaluation board.
After running modprobe jody-w3-pcieuart, checking the kernel log in dmesg will confirm that the WLAN driver (mlan_jody-w3-pcieuart.ko) was successfully loaded.

Additionally, the log confirms that the specified firmware (pcieuart9098_combo_v1.bin) is loaded correctly.

How to connect to a Wi-Fi Access point using nmtui

This article explains how to connect JODY-W3 to a Wi-Fi Access point on the MX8 evaluation board using nmtui.

1. Start nmtui

After the driver has been loaded by modprobe, run the nmtui command to start the nmtui (NetworkManager Text User Interface).

root@imx8qxpc0mek:~# modprobe jody-w3-pcieuart
root@imx8qxpc0mek:~# nmtui                                                                                         

2. Select "Activate a connection"

On the menu screen, select "Activate a connection" and press Enter.

3. Select SSID

A list of SSIDs of nearby Wi-Fi Access points will be displayed, so select the target SSID and activate it.

4. Enter your password

If Access point has security enabled, enter the password and press OK.

5. Check the connection status

If an "*" mark appears to the left of the SSID, the connection is successful. Select "Back" to return to the main menu.

6. Check connection information (optional)

Select "Edit a connection", select the SSID you are currently connected to, and click "Edit" to view detailed connection information (IP address, security settings, etc.).

7. Exit nmtui

Click "OK" to return to the default screen, then click "Quit" to exit nmtui and return to the normal terminal screen.

8. Check your IP address

Run ifconfig mlan0 in Terminal to verify that the Wi-Fi interface has been assigned a correct IP address.

root@imx8qxpc0mek:~# ifconfig mlan0
mlan0     Link encap:Ethernet  HWaddr 60:09:C3:85:56:01
          inet addr:192.168.10.151  Bcast:192.168.10.255  Mask:255.255.255.0
          inet6 addr: fe80::14e0:ed9c:b476:6e2c/64 Scope:Link
          inet6 addr: 240f:39:211f:1:6170:c9af:8148:c5cc/64 Scope:Global
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:123 errors:0 dropped:0 overruns:0 frame:0
          TX packets:99 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:14788 (14.4 KiB)  TX bytes:11600 (11.3 KiB)                                                                                        

9. Check network connectivity

Run ping 8.8.8.8 to check if you can connect to the Internet successfully.

root@imx8qxpc0mek:~# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=115 time=7.661 ms
64 bytes from 8.8.8.8: seq=1 ttl=115 time=7.113 ms
64 bytes from 8.8.8.8: seq=2 ttl=115 time=9.815 ms
64 bytes from 8.8.8.8: seq=3 ttl=115 time=8.474 ms
64 bytes from 8.8.8.8: seq=4 ttl=115 time=11.360 ms

Other than nmtui, other tools that can be used for Wi-Fi connection

nmtui is an interactive UI that is easy to use even for beginners, but if you want detailed control or automation, or if you are in an environment where a GUI cannot be used, other tools are effective. Here we will introduce two representative tools.

1. wpa_supplicant

Usage:
Connect to Access point as a Wi-Fi client (STA/Client mode)

Features:
It allows for detailed control via configuration files and is suitable for scripting and automation.

How to set it up:
Write the SSID, password, etc. in /etc/wpa_supplicant.conf

network={ 
ssid="YourSSID" 
psk="YourPassword" 
}

Example command:

sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf
sudo dhclient wlan0

2. hostapd

Usage:
Works as a Wi-Fi Access point (AP mode)

Features:
Multiple client management and detailed encryption settings are possible

How to set it up:

interface=wlan0
 ssid=MyAccessPoint
 hw_mode=g 
channel=6 
wpa=2 wpa_passphrase=YourPassword

Example command:

isudo hostapd /etc/hostapd.conf

How to install

i.MX evaluation board side:

Add iperf3 to IMAGE_INSTALL:append in local.conf.

IMAGE_INSTALL:append = " iperf3 "

On the other PC (e.g. Ubuntu):

Install iperf3 and net-tools.

sudo apt install iperf3 net-tools

On the other PC (e.g. Windows):

Download iperf3.exe from the official website and set the PATH.

Basic commands and execution procedures (server/client)

Server side (waiting for reception)

Start the server mode on either the PC or evaluation board to be measured.

iperf3 -s

Client side (start of transmission)

From the other device, specify the server's IP address to connect and begin measurement.

iperf3 -c <サーバーのIPアドレス>

example

iperf3 -c 192.168.10.151                                       

What is the NXP RF test tool "MFG Package/labtool"?

The MFG package/labtool is a kit that allows you to control and measure the RF output of the JODY-W3 directly from a PC. It can be used for everything from checking ANTENNAS characteristics at the early stages of design to radio wave certification tests (output, frequency, and modulation evaluation) and mass production inspections, all with a consistent operation.
The labtool on the PC side issues evaluation commands, and the mfgbridge on the i.MX8 side bridges the gap with the driver/FW to control and visualize the RF output.

What you can do with labtool

• Confirming RF performance at the early stage of design: Evaluating the wireless performance of boards and modules before mass production
• Radio wave certification test: Measures the output, frequency, and modulation characteristics required for certification in various countries, such as ITE (Japan), FCC (US), and CE (Europe).
• Process inspection: Checking RF characteristics during mass production and pre-shipment inspections
• Troubleshooting: Defect analysis and final adjustments during the design stage

Package contents list

The MFG package (Manufacturing Package) is a systematic collection of various tools, firmware, and documents required for JODY-W3 evaluation and RF testing.
The main directory structure and contents of the JODY-W3 MFG package are as follows:

RF evaluation system configuration and software architecture

The DUT (i.MX8 + JODY-W3), PC (labtool), and spectrum analyzer are connected via a LAN for command transmission and an RF coaxial CABLES for wireless output.

Data flow:

• Command transmission: labtool → LAN → mfgbridge
• Wireless module control: mfgbridge → driver/FW
• Output waveform measurement: RF output → spectrum analyzer

Software configuration and roles

• labtool (PC side): Issues RF test commands, sets parameters, and obtains results
• mfgbridge (evaluation board side): Communication mediator between labtool and kernel driver
• Driver (evaluation board side): Wireless module control, FW loading
• Firmware (module side): Wireless module operating LOGIC, RF output control

RF evaluation system configuration

Loading RF test driver/FW with modprobe

To use the RF test tools, the test drivers and firmware must be properly loaded on the i.MX8 evaluation board.
The normal version is /etc/modprobe.d/jody-w3-driver-pcieuart.conf, and the test version is /etc/modprobe.d/jody-w3 mfg.conf, and the parameter fw_name is specified in different places for both.

The role of configuration files

The configuration file for RF testing is /etc/modprobe.d/jody-w3-mfg.conf, which defines the driver load order and firmware path.

Here, we will explain how the driver and firmware are loaded using the modprobe command, based on the configuration file jody-w3-mfg.conf.

options jody-w3-mfg fw_name=nxp/jody-w3-mfg/pcieuart9098_combo.bin
options jody-w3-mfg cal_data_cfg=none
#options jody-w3-mfg cfg80211_wext=3
options jody-w3-mfg drv_mode=1
options jody-w3-mfg mfg_mode=1

install jody-w3-mfg \
        /sbin/modprobe -i mlan_jody-w3-pcieuart; \
        /sbin/modprobe -i moal_jody-w3-pcieuart $CMDLINE_OPTS; \
        /sbin/modprobe -i hci_uart

remove jody-w3-mfg \
        /sbin/rmmod moal mlan hci_uart ftdi_sio

options jody-w3-sdio-mfg fw_name=nxp/jody-w3-mfg/sdiouart9098_combo.bin
options jody-w3-sdio-mfg cal_data_cfg=none
#options jody-w3-sdio-mfg cfg80211_wext=0xf
options jody-w3-sdio-mfg drv_mode=1
options jody-w3-sdio-mfg mfg_mode=1

install jody-w3-sdio-mfg \
        /sbin/modprobe -i mlan_jody-w3-sdiouart; \
        /sbin/modprobe -i moal_jody-w3-sdiouart $CMDLINE_OPTS; \
        /sbin/modprobe -i hci_uart
remove jody-w3-sdio-mfg \
        /sbin/rmmod moal mlan hci_uart

If you define "install jody-w3-mfg" in the configuration file, the Wi-Fi PCIE driver will be loaded in the order of mlan to moal when modprobe jody-w3-mfg is executed (load source: /lib/modules//).
The Wi-Fi PCIE driver reads the firmware specified in the configuration file (e.g., fw_name=/lib/firmware/nxp/jody-w3-mfg/pcieuart9098_combo.bin) at startup and loads it into the wireless module.
In this way, simply specify the paths to the Wi-Fi PCIE driver and firmware in the configuration file and run the modprobe command, and the RF test kernel module and firmware will be automatically loaded in the correct order.

A practical guide to RF measurements using MFG package labtools and spectrum analyzers

Measurement procedure for RF characteristics of u-blox JODY-W3

We will explain the procedures and key points for measuring the RF characteristics of u-blox JODY-W3 using the NXP MFG package labtool and spectrum analyzer in a way that will be useful in the field.

Measurement preparation

1. Hardware setup

Required hardware:

• MX8 evaluation board: equipped with u-blox JODY-W3, measurement target (DUT)
• Windows PC: MFG package labtool installed, transmits commands to the evaluation board
• Spectrum analyzer: Measures the output waveform of RF signals
• LAN CABLES: Connect the evaluation board to a Windows PC
• RF coaxial CABLES ANTENNAS CONNECTORS: connects the RF output of the evaluation board to a spectrum analyzer

RF measurement equipment

Actual RF measurement

2. Preparing the software package

① Placement of MFG package on debug PC

Extract and place the MFG package on a Windows PC and use the Labtool_Windows folder. In this example, we extracted it directly under the C: drive.

② Firmware driver for the evaluation board

Check the following on the evaluation board:

• Is there a test firmware (combo/bin) under /lib/firmware/nxp/jody-w3-mfg/?
• Does the parameter fw_name in /etc/modprobe.d/jody-w3-mfg.conf specify the test firewall?

For detailed build instructions, please refer to the Nexty Electronics related technology column "Software Resource Placement for u-blox Modules."

Preparation flow before running the RF test app labtool

*This procedure is required every time POWER SUPPLIES is turned on.

1. Start the i.MX8 evaluation board and log in via SSH

For detailed instructions, please refer to the NEXTY Electronics related technology column "How to Debug an i.MX8 Evaluation Board: Using USB Serial Connection and Ethernet SSH."

2. Load the RF test driver with modprobe

After logging in via SSH on Teraterm on a Windows PC, run the modprobe command.
If no error message is displayed and the prompt returns, then it's OK.

3. Run the bridge application mfgbridge

① Use the cd command to move to the directory (opt/jody-w3/mfg-tools).

② Use the ls command to confirm that “mfgbridge” exists under it.

③ At the prompt in the same directory, run "./mfgbridge".

④ If the network communication initialization message appears in the response log, it's OK.

Now the i.MX8 board is ready to be bridged with a Windows PC.

4. Open the labtool_Windows folder on your Windows PC.

Open Labtool_Windows in the MFG package on a Windows PC.

5. Open the labtool setting file (SetUp.ini)

Open the SetUp.ini file in a text editor.

6. Edit the IP address in SetUp.ini

Overwrite the IP address part of DutIpAddress = <IP address> in the SetUp.ini file with the Ethernet IP address value assigned to the i.MX8 evaluation board by DHCP.
For information on how to check the IP address value, please refer to the NEXTY Electronics related column How to debug the i.MX8 evaluation board: How to use USB serial connection and Ethernet SSH.

7. Run labtool

Double-click DutApiMimoApApp.exe in Labtool_Windows.

The labtool application prompt screen will launch.

Name:           Dut labtool
Version:        2.0.0.92
Date:           May 27 2024 (00:38:23)

Note:

1. =========WiFi tool=============
2. =========BT   tool=============

- Enter CMD 99 to Exit

Enter option: 

8. Check the startup of labtool's Wi-Fi command input

Select Wi-Fi 1 under Enter option and press ENTER.
The IP addresses of the DUT i.MX8 evaluation board and the Host Windows PC are displayed, and if the W90xx (802.11a/g/b/n/ac/ax) TEST MENU is displayed, then preparation for command input is successful.

Overview of the labtool RF test application and Wi-Fi command specifications

This article summarizes the basic functions and Wi-Fi command specifications of NXP's RF test application labtool based on the user guide.
To obtain the labtool user guide, you must have a license agreement with NXP.
For details, please Inquiry Nexty Electronics.
When you are ready to enter the labtool Wi-Fi commands, press Enter to execute the labtool commands and display the Wi-Fi transmission waveform on the spectrum analyzer.

labtool command specification

Menu-driven: labtool operates via a command line interface (CLI), allowing you to select various RF test modes and parameters through menu selection.

Command structure: Commands are structured as follows: "Select function" → "Enter parameter" → "Enter." For example, you would enter "Set frequency," "Set bandwidth," and "Set transmission power" in that order.

Wi-Fi Commands: Wi-Fi RF and certification tests are performed using a combination of commands such as the following:

About Command 6

Here, we will use command 6 as an example to explain the command function, along with the internal circuitry of JODY-W3.
Labtool command 6 (Set Radio Mode Index) specifies the operating band and ANTENNAS configuration for Radio 0 and Radio 1.

Command Format

What are Radio0 and Radio1?

"Radio0" and "Radio1" in labtool refer to the two radio circuits installed inside the JODY-W3 module.

• Radio0: Responsible for Wi-Fi communication in the 5GHz band
• Radio1: Responsible for 2.4GHz Wi-Fi communications

The figure below is the internal block diagram of JODY-W3.

JODY-W3 internal block diagram

What is the Radio Mode Index?

The JODY-W3's Radio 0 and Radio 1 can be set independently for band (2.4GHz/5GHz) and ANTENNAS path (Path A/B/A+B). The two systems can also be operated simultaneously in different radio modes.
The following are typical Radio modes for JODY-W3 (assuming firmware Rev.X). Commands not listed depend on the product/FW configuration.

What is Path (ANTENNAS path)?

Inside a wireless module such as JODY-W3, there are multiple ANTENNAS paths leading to ANTENNAS TERMINALS. JODY-W3 has Path A and Path B for each of the Radio 0 and Radio 1 systems.

What this means in the Radio Mode Table:

• Path A: Use only Path A as RF output
• Path B: Uses only Path B for RF output
• Path A+B: Path A and Path B are used simultaneously as RF output (2x2 MIMO operation is possible by implementing two ANTENNAS)

Command 6 usage example

Example 1: 2x2 MIMO transmission in the 5GHz band

6 1 0

Example 2: 1x1 transmission (Path A) in the 2.4GHz band

6 11 0

Example 3: 2x2 MIMO transmission in the 2.4GHz band

6 ９ 0

Practice RF measurements with labtools and spectrum analyzers

Here we will introduce an example of measuring Wi-Fi RF output waveforms using a labtool and spectrum analyzer, based on the command reference in the labtool user guide for NXP's 88Q9098. We will actually use a labtool to obtain Wi-Fi RF output waveforms using a spectrum analyzer, following the command reference in the labtool user guide for NXP's 88Q9098.

802.11n 2.4GHz output 20MHz bandwidth Transmit power 8dBm MCS7 2x2 mode command example:

User Guide Command Sequence Example 1

Log of the commands listed in the manual executed in order

--------------------------------------------------------
                W90xx (802.11a/g/b/n/ac/ax) TEST MENU
--------------------------------------------------------
Enter option: 6 0 9
DutIf_SetRadioMode_W909X: 0x00000000
Enter option: 112 1 0
 Radio0 Mode = 0, Radio1 Mode = 9
DutIf_SetChannelBw: 0x00000000
Enter option: 12 1 1
 Radio0 Mode = 0, Radio1 Mode = 9
 DutIf_SetRfChannel: 0x00000000
 RF Channel: 1 (2412.0 MHz)
Enter option: 35 1 1 22 8
 DutIf_AdjustPcktSifs_W909X: 0x00000000 DeviceId=1
        Power Level: 8.0000 dBm
Enter option:

Spectrum analyzer output waveform (Path A: ANT0 TERMINALS)

Spectrum analyzer output waveform (Path B: ANT1 TERMINALS)

The spectrum waveform is correctly output with a center frequency of 2.421 GHz and a bandwidth of 20 MHz, in accordance with the specified command.
Note that the 8 dBm power level setting is the integrated value over the entire bandwidth, which does not match the peak level displayed on the spectrum analyzer. Therefore, the spectrum analyzer used here does not directly convert the integrated value to the peak value.

802.11ax 5GHz output 80MHz bandwidth Transmit power 8dBm MCS7 2x2 mode command example:

User Guide Command Sequence Example 2

Log of the commands listed in the manual executed in order

--------------------------------------------------------
                W90xx (802.11a/g/b/n/ac/ax) TEST MENU
--------------------------------------------------------
Enter option: 6 1 0
DutIf_SetRadioMode_W909X: 0x00000000
Enter option: 112 0 4
 Radio0 Mode = 1, Radio1 Mode = 0
DutIf_SetChannelBw: 0x00000000
Enter option: 12 0 36 48
 Radio0 Mode = 1, Radio1 Mode = 0
 DutIf_SetRfChannel: 0x00000000
 RF Channel: 36 (5180.0 MHz) offset 1
Enter option: 225 0 1 2111 8
 DutIf_AdjustPcktSifs11ax_W909X: 0x00000000 DeviceId=0
        Power Level: 8.0000 dBm
Enter option:

Spectrum analyzer output waveform (Path A: ANT0 TERMINALS)

Spectrum analyzer output waveform (Path B: ANT1 TERMINALS)

The spectrum waveform is output correctly across the full 80 MHz bandwidth from channel 36 (center frequency 5.18 GHz) to channel 48 (center frequency 5.24 GHz) in accordance with the specified command.
In this way, we have confirmed that wideband (80MHz) signals combining multiple channels can be observed within the specified frequency range.
Note that the 8 dBm power level setting indicates the integrated value (total power) over the entire bandwidth. On the other hand, spectrum analyzers usually display the peak level (maximum value at a single frequency), and the two do not match. For this reason, the spectrum analyzer used here does not perform a direct conversion between the integrated value and the peak value.

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