STM32MP157 Discovery Kit🔗

Introduction🔗

The PAN9019A requires a fairly powerful host processor that executes the low-level Wi-Fi® and Bluetooth® drivers as well as some high-level Wi-Fi application software and a Bluetooth stack.

As an evaluation platform you can use the STM32MP157 Discovery Kit.

It does not have an on-board M.2 Key E slot for the PAN9019A M.2 device, but an additional SDIO interface and other peripherals can be enabled on the 40-pin expansion header.

To bring the PAN9019A M.2 device and the STM32MP157 Discovery Kit together, you can use the M.2 to Raspberry Pi Adapter.

This guide shows you how to evaluate a Panasonic PAN9019A M.2 device on a STM32MP157 Discovery Kit with the help of the M.2 to Raspberry Pi Adapter. But you have to be aware that only the basic bring-up is explained, not any advanced usage.

Hardware Modifications🔗

You have to do some hardware modification to the PAN9019A M.2 device before you can use it together with the STM32MP157 Discovery Kit.

The following requirement must be met:

You have a PAN9019A M.2 device.

SDIO and IO Reference Voltages🔗

The interfaces on the 40-pin expansion header of the STM32MP157 Discovery Kit operate with 3.3 V signal level, while the PAN9019A M.2 device operates with 1.8 V instead.

Because of this you have to modify the PAN9019A M.2 device as explained in Hardware Modifications in order to change the SDIO and IO reference voltages to 3.3 V.

Note

A signal level of 3.3 V limits the SDIO clock speed to 50 MHz, which also limits the maximum achievable data rate severely.

For further information please refer to the module product specification at

I²C GPIO Expander Signal Voltages🔗

The PAN9019A module contains an I²C GPIO Expander chipset whose signal levels on the clock and data lines are tied to 1.8 V using pull-up resistors. You have to remove these pull-up resistors so that the PAN9019A M.2 device can interface with 3.3 V signal levels instead.

You have to do the following steps to remove the pull-up resistors.

Unsolder the resistor R12.
Unsolder the resistor R13.

Signal Level Mismatch

You cannot easily change the input reference voltage of the I²C GPIO Expander chipset to 3.3 V as well. Because of this there is a mismatch regarding the input voltages.

The I²C GPIO Expander expects 1.8 V signal levels, while the I2C clock and data lines are operated with 3.3 V instead.

Nevertheless no communication problems were observed during the evaluation of this setup.

Host System Assembly🔗

The following requirements must be met:

You have a STM32MP157 Discovery Kit (host system).
You have a M.2 to Raspberry Pi Adapter.
You have a modified PAN9019A M.2 device.

You have to do the following steps to assemble the system.

Mount the PAN9019A M.2 device 3 onto the M.2 to Raspberry Pi Adapter 2 as explained in First Steps.
Mount the M.2 to Raspberry Pi Adapter 2 onto the 40-pin expansion header of the STM32MP157 Discovery Kit 1.
Power the M.2 to Raspberry Pi Adapter through the USB-C connector 4, otherwise the adapter is non-functional.

Host System Setup🔗

Note

Please note that you need an myST account to be able to access any of the mentioned documents.

Initial Bring-Up🔗

You have to follow the Let's start guide in the STM32 MPU Ecosystem User Guide to bring up your STM32MP157 Discovery Kit.

This includes the following steps:

Setting up the development system
Installing the necessary tools
Downloading an image binary
Populating the SD card of the STM32MP157 Discovery Kit
Booting the STM32MP157 Discovery Kit

This guide is based on the following versions:

en.flash-stm32mp1-openstlinux-6.1-yocto-mickledore-mpu-v24.06.26.tar.gz

Network Connectivity🔗

You have to make sure that the STM32MP157 Discovery Kit is on the same network as your development system, because you need to interact with your host system and maybe transfer files to it in later steps.

You have to check and remember the IP address of your host system for later use.

On your host system, retrieve the current network configuration for the on-board Ethernet port in a Terminal window.

ip addr show eth0

The output should look something like this:

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
  link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
  inet 192.168.187.100/24 brd 192.168.187.255 scope global dynamic noprefixroute eth0
    valid_lft 86089sec preferred_lft 86089sec
  inet6 fe80::xxxx:xxxx:xxxx:xxxx/64 scope link noprefixroute
    valid_lft forever preferred_lft forever

The IP address of your host system is 192.168.187.100

Host System IP Address

For this host system the IP address is 192.168.187.100, but it may be different for yours.

In any case you have to use this IP address to communicate with your host system for the remainder of this document.

You have to follow Check the host computer Internet access to make sure that your host system has access to the Internet.

Host System Remote Access

If you do not have any application for the SSH protocol yet, you can try the OpenSSH protocol suite.

It also includes tools for remote file operations like ssh and scp.

At the end of this process you should have a fully working system you can remotely log into.

Host System Configuration🔗

The following requirements must be met:

You have brought up your STM32MP157 Discovery Kit as explained in Host System Setup.
You can access your STM32MP157 Discovery Kit remotely.

Install Additional Packages🔗

You have to install the following packages on your host system for later use:

device tree compiler package that provides tools for device tree handling, like fdtput and dtc
nano package that provides the nano text editor
git package that provides the git version control system

Update the package index on the host system.
```
apt update
```
Install the additional packages.
```
apt install dtc nano git
```

Enable Peripheral Interfaces🔗

You have to enable additional peripheral interfaces on the 40-pin expansion header.

Enable and configure an additional SDIO interface.
```
fdtput -d /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/mmc@48004000 status
fdtput -t s /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/mmc@48004000 status okay
fdtput /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/mmc@48004000 no-1-8-v
fdtput /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/mmc@48004000 broken-cd
```
Non-recommended Setting

Setting the option broken-cd (for broken card detect) is not recommended and you should never use it in a product.

It makes the Linux kernel poll the interface regularly and can disturb the operation of the device if it happens at the wrong time.

However, in this setup, it makes the reset button on the M.2 to Raspberry Pi Adapter work and helps you during the evaluation.

Enable an additional UART interface.

fdtput -d /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/serial@4000f000 status
fdtput -t s /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/serial@4000f000 status okay

Enable an additional I2C interface.

fdtput -d /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/i2c@40015000 status
fdtput -t s /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/i2c@40015000 status okay

Enable an additional SPI interface.

fdtput -d /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/spi@44009000 status
fdtput -t s /boot/stm32mp157d-dk1.dtb /soc/etzpc@5c007000/spi@44009000 status okay

Enable I²C GPIO Expander Expander🔗

You have to enable support for the I²C GPIO Expander in the device tree of the STM32MP157 Discovery Kit.

Navigate to the directory that contains the device tree.
```
cd /boot/
```

Decompile the currently used device tree.

dtc -I dtb -O dts stm32mp157d-dk1.dtb -o tree.dts

Open the decompiled device tree with the nano editor.
```
nano tree.dts
```

Locate the node named i2c@40015000 and add the following information at the end of the section before the closing parenthesis.

m2_expander: pcal6408@20
{
  compatible = "nxp,pcal6408";
  reg = <0x20>;
  gpio-controller;
  #gpio-cells = <2>;
  gpio-line-names = "UNUSED", "IND_RST_15.4", "WL_WAKE_IN", "BT_WAKE_IN", "RST_IND", "UNUSED", "UNUSED", "UNUSED";
};

Locate the node named spi@44009000 and add the following information at the end of the section before the closing parenthesis.

cs-gpios = <0x8a 0x06 1>;

spidev0: spi@0 {
  reg = <0>;
  compatible = "rohm,dh2228fv";
  spi-max-frequency = <10000000>;
};

Assemble the modified device tree.

dtc -I dts -O dtb tree.dts -o stm32mp157d-dk1.dtb

System Reboot

You have to reboot the host system for these changes to take effect.

reboot

Development System Setup🔗

Note

This guide assumes that you follow the recommendations for the directory structure as explained in Example of directory structure for Packages.

Setup Development Environment🔗

You have to setup the development environment on your development system and follow the Develop on Arm® Cortex®-A7 guide.

This includes the following steps:

Installing some extra packages
Downloading the SDK
Running the installation script
Starting the SDK

Note

You can skip the step to create a simple application and you don't need to rebuild the Linux kernel.

Setup Linux Kernel Build Environment🔗

You have to setup the build environment for the Linux kernel and follow the Modify, rebuild and reload the Linux® kernel guide.

This includes the following steps:

Downloading the BSP that contains the Linux kernel source code
Preparing the Linux kernel source code

You don't have to build the Linux kernel, however, you need to prepare the kernel.

In the Linux kernel directory, execute the following statement to prepare the kernel.
```
make O=${OUTPUT_BUILD_DIR} prepare
```

This guide is based on the following versions:

en.sdk-x86_64-stm32mp1-openstlinux-6.1-yocto-mickledore-mpu-v24.06.26.tar.gz
en.sources-stm32mp1-openstlinux-6.1-yocto-mickledore-mpu-v24.06.26.tar.gz

rgpower Files🔗

Before you can fully operate the PAN9019A, a set of so-called rgpower files is required. These files contain channel tables and regulatory parameters of the PAN9019A for a specific region it operates in.

For further information on this topic refer to rgpower Files in the Software Guide for the PAN9019A.

Since these files are provided by Panasonic you need to transfer them to the system manually in a later step.

To gain access to the rgpower files you have to go through an uncomplicated approval process that you can find directly on the following pages.

Warning

The PAN9019A is a radio certified module. There are conditions on hardware and software which must be met for the modular approval to be valid.

For detailed information please refer to the PAN9019A Module Integration Guide at

However, if you want to continue right away you can also start with the single world-wide (WW) rgpower file, which is the fall-back regulatory file for all regions the module is certified for.

The world-wide rgpower file has a couple restrictions compared to the region-specific rgpower files:

Support for channels 1 to 11 in 2.4 GHz band only
No support for 5 GHz band
Overall reduced output power

For the initial evaluation of the PAN9019A module the world-wide rgpower file is available from the Downloads section.

You can download it directly when you setup your host system as explained in Install rgpower Files in a later step.

Host System Software Installation🔗

The following requirement must be met:

You have brought up your development system as explained in Development System Setup.

You have to make sure that the development environment is initialized.

Execute the initialization script of the SDK.

. ~/STM32MPU_workspace/STM32MPU-Ecosystem-v5.1.0/Developer-Package/SDK/environment-setup-cortexa7t2hf-neon-vfpv4-ostl-linux-gnueabi

Compile Missing Kernel Module🔗

The default kernel lacks support for the I²C GPIO Expander chipset that is present on the PAN9019A M.2 device, so you have to compile the driver manually.

Navigate to the base directory of the Linux kernel.

cd ~/STM32MPU_workspace/STM32MPU-Ecosystem-v5.1.0/Developer-Package/stm32mp1-openstlinux-6.1-yocto-mickledore-mpu-v24.06.26/sources/arm-ostl-linux-gnueabi/linux-stm32mp-6.1.82-stm32mp-r2-r0/linux-6.1.8

Download a configuration fragment from the Development Hub.

wget -O ./st-gpio-expander-fragment.cfg  \
  https://pideu.panasonic.de/development-hub/pan9019/downloads/st-gpio-expander-fragment.cfg

Merge the configuration fragment into the Linux kernel configuration.

scripts/kconfig/merge_config.sh -m -r -O ${OUTPUT_BUILD_DIR} ${OUTPUT_BUILD_DIR}/.config ~/st-gpio-expander-fragment.cfg 
yes '' | make oldconfig O=${OUTPUT_BUILD_DIR}

Compile all kernel driver modules.
```
make O=${OUTPUT_BUILD_DIR} modules
```

Copy the missing driver to your host system.

scp ${OUTPUT_BUILD_DIR}/drivers/gpio/gpio-pca953x.ko root@192.168.187.100:/lib/modules/6.1.82/extra/

Compile the Device Driver🔗

You have to download the PAN9019A module device driver, compile it and transfer it to the host system.

Navigate to the base of your working environment.

cd ~/STM32MPU_workspace/STM32MPU-Ecosystem-v5.1.0/

Clone the driver repository from NXP's GitHub space.

git clone https://github.com/nxp-imx/mwifiex.git
cd mwifiex/
git checkout lf-6.6.23_2.0.0
cd mxm_wifiex/wlan_src/

You have to disable support for some unused devices inside the driver.

Use the nano editor to open the file and change it as described.

nano Makefile

Makefile
# Multi-chipsets
[...]
CONFIG_SD8997=y
CONFIG_USB8997=n
CONFIG_PCIE8997=n
CONFIG_SD8987=y
CONFIG_SD9097=n
[...]
CONFIG_SD9098=y
CONFIG_USB9098=n
CONFIG_PCIE9098=n
CONFIG_SDIW624=n
CONFIG_SDAW693=n
[...]

You have to download and apply a custom patch from the Development Hub to fix an incorrect version check in the driver.

wget -O ./nxp-fix-version-check.patch  \
  https://pideu.panasonic.de/development-hub/pan9019/downloads/nxp-fix-version-check.patch
patch -p1 < ./nxp-fix-version-check.patch

Compile the device driver.

make O="${OUTPUT_BUILD_DIR}" KERNELDIR=~/STM32MPU_workspace/STM32MPU-Ecosystem-v5.1.0/Developer-Package/stm32mp1-openstlinux-6.1-yocto-mickledore-mpu-v24.06.26/sources/arm-ostl-linux-gnueabi/linux-stm32mp-6.1.82-stm32mp-r2-r0/linux-6.1.82 build

Copy the device driver to your host system.

scp mlan.ko moal.ko root@192.168.187.100:/lib/modules/6.1.82/extra/

Install the Firmware🔗

You have to download and install the firmware for the PAN9019A module.

Create the destination directory for the firmware and configuration files.
```
mkdir -p /lib/firmware/nxp/
```

Clone the firmware repository from NXP's GitHub space.

cd ~
git clone https://github.com/nxp-imx/imx-firmware.git
cd imx-firmware/
git checkout lf-6.6.23_2.0.0

Copy the firmware to the global firmware directory.

cd ~/imx-firmware
cp nxp/FwImage_IW612_SD/sduart_nw61x_v1.bin.se /lib/firmware/nxp/

Copy the configuration file wifi_mod_para.conf to the global firmware directory.
```
cd ~/imx-firmware
cp nxp/wifi_mod_para.conf /lib/firmware/nxp/
```

Edit the SDIW612 section in the file wifi_mod_para.conf using the nano editor to contain the following settings.

nano /lib/firmware/nxp/wifi_mod_para.conf

wifi_mod_para.conf

SDIW612 = {
    cal_data_cfg=none
    fw_name=nxp/sduart_nw61x_v1.bin.se
    cntry_txpwr=2
}

Install rgpower Files🔗

As explained in rgpower Files the PAN9019A module needs proper rgpower files to operate.

If you already have your set of rgpower files, you have to copy them to the /lib/firmware/nxp/ directory on your host system.

If you do not have your set of rgpower files yet and want to use the single world-wide (WW) rgpower file instead, you can download it directly to the host system.

Download the rgpower file to the global firmware directory.

wget -O /lib/firmware/nxp/rgpower_WW.bin \
  https://pideu.panasonic.de/development-hub/pan9019/downloads/rgpower_WW.bin

Wi-Fi🔗

Bring Up🔗

The newly compiled device drivers are not loaded into the Linux kernel automatically, you have to manually load them into the kernel prior to operation.

Make sure that Linux kernel module dependency database is up-to-date.
```
depmod -a
```

Load the modules into the Linux kernel.

modprobe mlan
modprobe moal mod_para=nxp/wifi_mod_para.conf

Check the Linux kernel log.

dmesg

The output should look something like this:

[  263.436351] Request firmware: nxp/sduart_nw61x_v1.bin.se
[  263.852847] Wlan: FW download over, firmwarelen=1038668 downloaded 936668
[  264.256233] WLAN FW is active
[  264.300156] on_time is 264296058797
[  264.374828] VDLL image: len=102000
[  264.376130] fw_cap_info=0x487cff03, dev_cap_mask=0xffffffff
[  264.376158] uuid: 068bfcc4ba1d528786ce818360ed4555
[  264.376162] max_p2p_conn = 8, max_sta_conn = 16
[  264.389119] Trying download country_power_tble: nxp/rgpower_WW.bin
[  264.463300] Request firmware: nxp/rgpower_WW.bin
[  264.629607] call regulatory_set_wiphy_regd WW
[  264.663429] Register NXP 802.11 Adapter mlan0
[  264.767939] wlan: uap%d set max_mtu 2000
[  264.819529] Register NXP 802.11 Adapter uap0
[  264.884398] call regulatory_set_wiphy_regd WW
[  264.896841] Register NXP 802.11 Adapter wfd0
[  265.000308] wlan: version = SDIW612---18.99.3.p10.1-MM6X18437.p21-GPL-(FP92) 
[  265.125657] uap0: Skip change virtual intf type on uap: from 3 to 2

Note

If you can't see that the PAN9019A M.2 device was detected, press the reset button 6 button of the M.2 to Raspberry Pi Adapter briefly once.

This resets the PAN9019A module, but also triggers the detection in the Linux kernel again.

You can now check the functionality of the driver.

Use the ip command to verify that the mlan0 network interface for the PAN9019A is now available.

ip addr show mlan0

The output should look something like this:

3: mlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
  link/ether 34:32:e6:xx:xx:xx brd ff:ff:ff:ff:ff:ff

Usage🔗

You have to follow these steps to check if Wi-Fi is functional.

Bring up the Wi-Fi interface.
```
ip link set dev mlan0 up
```
Execute a Wi-Fi scan.
```
iw dev mlan0 scan
```
You can see that nearby Wi-Fi networks are discovered successfully.

Bluetooth🔗

The following requirement must be met:

You have successfully brought up the Wi-Fi portion as explained in Wi-Fi.

Bring Up🔗

You have to follow these steps to bring up the Bluetooth interface.

Initialize the Bluetooth interface.
```
hciattach /dev/ttySTM1 any 115200 flow
```
The output should look something like this:
```
Device setup complete
```
Bring up the Bluetooth interface.
```
hciconfig hci0 up
```

Usage🔗

You have to follow these steps to check if Bluetooth is functional.

Execute a Bluetooth scan.
```
bluetoothctl scan on
```
You can see that nearby Bluetooth devices that are advertising are discovered successfully.

802.15.4🔗

The following requirement must be met:

You have successfully brought up the Wi-Fi portion as explained in Wi-Fi.

Software Setup🔗

There is no integrated support for OpenThread using the 802.15.4 radio portion of the PAN9019A, so you have to compile the necessary software on your development system.

Navigate to the base of your working environment.

cd ~/STM32MPU_workspace/STM32MPU-Ecosystem-v5.1.0/

Clone the official OpenThread repository and checkout a version that matches the driver version.

git clone https://github.com/openthread/openthread.git
cd openthread
git checkout 5beae143700db54c6e9bd4b15a568abe2f305723
cd ..

Clone NXP's meta-matter repository and checkout a version that matches the driver version, too.

git clone https://github.com/nxp-imx/meta-matter.git
cd meta-matter
git checkout imx_matter_2024_q1
cd ..

The official OpenThread stack does not work out-of-the-box with the PAN9019A module yet.

Apply an NXP-specific patch from the meta-matter repository to make the OpenThread stack fully work.
```
cd openthread
patch -p1 < ../meta-matter/recipes-openthread/openthread/files/0001-Apply-IW612-change-to-openthread.patch
```

Compile the OpenThread stack.

./script/cmake-build posix -GNinja -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
    -DOT_COMPILE_WARNING_AS_ERROR=OFF -DOT_PLATFORM=posix -DOT_SLAAC=ON \
    -DOT_BORDER_AGENT=ON -DOT_BORDER_ROUTER=ON -DOT_COAP=ON -DOT_COAP_BLOCK=ON \
    -DOT_COAP_OBSERVE=ON -DOT_COAPS=ON -DOT_COMMISSIONER=ON -DOT_CHANNEL_MANAGER=ON \
    -DOT_CHANNEL_MONITOR=ON -DOT_CHILD_SUPERVISION=ON -DOT_DATASET_UPDATER=ON \
    -DOT_DHCP6_CLIENT=ON -DOT_DHCP6_SERVER=ON -DOT_DIAGNOSTIC=ON -DOT_DNS_CLIENT=ON \
    -DOT_ECDSA=ON -DOT_IP6_FRAGM=ON -DOT_JAM_DETECTION=ON -DOT_JOINER=ON \
    -DOT_LEGACY=ON -DOT_MAC_FILTER=ON -DOT_NETDIAG_CLIENT=ON \
    -DOT_NEIGHBOR_DISCOVERY_AGENT=ON -DOT_PING_SENDER=ON -DOT_REFERENCE_DEVICE=ON \
    -DOT_SERVICE=ON -DOT_SNTP_CLIENT=ON -DOT_SRP_CLIENT=ON -DOT_COVERAGE=OFF \
    -DOT_LOG_LEVEL_DYNAMIC=ON -DOT_RCP_RESTORATION_MAX_COUNT=2 \
    -DOT_LOG_OUTPUT=PLATFORM_DEFINED -DOT_POSIX_MAX_POWER_TABLE=ON -DOT_DAEMON=ON \
    -DOT_THREAD_VERSION=1.3 -DCMAKE_BUILD_TYPE=Release -DOT_POSIX_CONFIG_RCP_BUS=SPI

Transfer the application files to the host system.

scp ./build/posix/src/posix/ot-daemon ./build/posix/src/posix/ot-ctl \
  root@192.168.187.100:~

Bring Up🔗

The reset function of the 802.15.4 subsystem of the PAN9019A module is controlled using the I²C GPIO Expander on the PAN9019A M.2 device.

It is important that the I²C GPIO Expander is correctly recognized by the STM32MP157 Discovery Kit during boot, otherwise it cannot be used by the OpenThread stack later.

You have to follow these steps to verify that the I²C GPIO Expander is really available.

Reboot the host system.
```
reboot
```
Check if an additional I²C GPIO Expander with the signature [1-0020] is present.
```
gpiodetect
```
The output should look something like this:
```
[...]
gpiochip10 [1-0020] (8 lines)
[...]
```
The I²C GPIO Expander gpiochip10 is present in the host system.

You can verify that the OpenThread stack starts correctly as follows.

Start the OpenThread daemon ot-daemon with the following configuration to run in the background.

cd ~
./ot-daemon -v "spinel+spi:///dev/spidev0.0?gpio-int-device=/dev/gpiochip5&gpio-int-line=3&gpio-reset-device=/dev/gpiochip10&gpio-reset-line=1&spi-mode=0&spi-speed=500000&spi-reset-delay=500" &

The output should look something like this:

./ot-daemon[608]: Running OPENTHREAD/thread-reference-20230706-12-g5beae1437-dirty; POSIX; May 22 2024 13:50:08
./ot-daemon[608]: Thread version: 4
./ot-daemon[608]: Thread interface: wpan0
./ot-daemon[608]: RCP version: OPENTHREAD/thread-reference-20180926-4730-gad808304f; IWX12; Dec 15 2023 12:28:58

The version information of the OpenThread stack is shown correctly.

Usage🔗

You can verify that the OpenThread stack operates correctly as follows.

Perform a factory reset to verify the communication.

./ot-ctl factoryreset

The output should look something like this:

./ot-daemon[608]: Running OPENTHREAD/thread-reference-20230706-12-g5beae1437-dirty; POSIX; May 22 2024 13:50:08
./ot-daemon[608]: Thread version: 4
./ot-daemon[608]: Thread interface: wpan0
./ot-daemon[608]: RCP version: OPENTHREAD/thread-reference-20180926-4730-gad808304f; IWX12; Dec 15 2023 12:28:58

The version information of the OpenThread stack is shown correctly.

Appendix🔗

The PAN9019A module has a couple of special function pins that are routed to the 40-pin expansion header as follows.

Chip / Line	STM32MP157	Pin Header	M.2 Specification	PAN9019A	Description
6 / 2	PG2	GPIO 5	W_DISABLE1#	PDn	Power Down
7 / 11	PH11	GPIO 6	W_DISABLE#2	IND_RST_BT	Bluetooth reset
0 / 8	PA8	GPIO 4	SDIO_RST#	IND_RST_WL	Wi-Fi reset

You can manually control the special function pins using the gpioset tool. For example:

Apply GND to GPIO 5 to signal power down to the module.
```
gpioset -c 6 2=0
```
Apply VCC to GPIO 5 to enable the module again.
```
gpioset -c 6 2=1
```

Some more special function pins of the PAN9019A module are routed to the I²C GPIO Expander as follows.

I²C GPIO Expander	PAN9019A	Description
3	IND_RST_14.4	802.15.4 reset
7	RST_IND	Reset indicator

STM32MP157 Discovery Kit🔗

Introduction🔗

Hardware Modifications🔗

SDIO and IO Reference Voltages🔗

I2C GPIO Expander Signal Voltages🔗

Host System Assembly🔗

Host System Setup🔗

Initial Bring-Up🔗

Network Connectivity🔗

Host System Configuration🔗

Install Additional Packages🔗

Enable Peripheral Interfaces🔗

Enable I2C GPIO Expander Expander🔗

Development System Setup🔗

Setup Development Environment🔗

Setup Linux Kernel Build Environment🔗

rgpower Files🔗

Host System Software Installation🔗

Compile Missing Kernel Module🔗

Compile the Device Driver🔗

Install the Firmware🔗

Install rgpower Files🔗

Wi-Fi🔗

Bring Up🔗

Usage🔗

Bluetooth🔗

Bring Up🔗

Usage🔗

802.15.4🔗

Software Setup🔗

Bring Up🔗

Usage🔗

Appendix🔗

I²C GPIO Expander Signal Voltages🔗

Enable I²C GPIO Expander Expander🔗