dawei8823 / zephyr_wifi

Example Zephyr WiFi code

Zephyr WiFi Code

Simple example Zephyr WiFi code is targeted for the ESP32 and ESP32C3, although it should be platform-agnostic.

Connects to a WiFi network, obtains an IPv4 address via DHCP and disconnects after 30 seconds.

*** Booting Zephyr OS build zephyr-v3.2.0-2019-g7ac69dc4ca95 ***
Connecting to SSID: Welcome_IN
Connected
IPv4 address: 192.168.0.67
Subnet: 255.255.255.0
Router: 192.168.0.254
Disconnected

Building for ESP32 (xtensa)

Follow the Getting Started Guide to install Zephyr and the build tools.

git clone https://github.com/craigpeacock/Zephyr_ESP32_WiFi.git
cd Zephyr_ESP32_WiFi
west blobs fetch hal_espressif
west build -b esp32
west flash
west espressif monitor

Building for ESP32C3 (RISC-V)

Follow the Getting Started Guide to install Zephyr and the build tools.

git clone https://github.com/craigpeacock/Zephyr_ESP32_WiFi.git
cd Zephyr_ESP32_WiFi
west blobs fetch hal_espressif
west build -b esp32c3_devkitm
west flash
west espressif monitor

Troubleshooting

West blobs fetch hal_espressif downloads WiFi and Bluetooth binary blobs required for the ESP32. If these are not installed, you are likely to get linker errors resulting from missing files such as

cannot find -lnet80211: No such file or directory
cannot find -lcore: No such file or directory
cannot find -lpp: No such file or directory
cannot find -lcoexist: No such file or directory
cannot find -lphy: No such file or directory
cannot find -lmesh: No such file or directory

The RISC-V architecture (ESP32C3) requires the kconfig option CONFIG_HEAP_MEM_POOL_SIZE=32768 otherwise multiple errors result with undefined reference to `k_malloc'

If this value is too small, errors can result loading the WiFi driver at runtime:

[00:00:00.003,000] <err> esp32_wifi_adapter: memory allocation failed          
[00:00:00.005,000] <err> esp32_wifi: Failed to start Wi-Fi driver  

nrf7002dk_nrf5340_cpuapp (Nordic nRF7002)

This project currently builds and sucessfully connects when using nRFConnect SDK 2.2.0 and 2.3.0. Support for the nRF7002 is very new and change should be expected as the code matures over time. Below is a list of common issues encounted when porting your Zephyr WiFi code to the nRF7002 target:

Troubleshooting

It may be observed when using SDK 2.3.0 that the following error (Unable to get wpa_s handle for wlan0) is reported at runtime:

WiFi Example
Board: nrf7002dk_nrf5340_cpuapp
Connecting to SSID: test_ap
[00:00:00.600,189] <inf> wpa_supp: z_wpas_start: 385 Starting wpa_supplicant thread with debug level: 3
[00:00:00.600,402] <inf> wpa_supp: Successfully initialized wpa_supplicant
[00:00:00.600,830] <err> wpa_supp: z_wpas_get_handle_by_ifname: Unable to get wpa_s handle for wlan0

Examing nRF7002 code from Nordic, it appears they have put a 1 second day in after registering the callbacks, and before calling wifi_connect(). This was not required in SDK 2.2.0

To prevent the following build error

\wifi\nrf700x\zephyr\src\shim.c:14:10: fatal error: sys/time.h: No such file or directory

add the following to your prj.conf:

CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=n

To prevent build error

undefined reference to `z_impl_sys_rand32_get'

and the following to your prj.conf:

CONFIG_ENTROPY_GENERATOR=y
CONFIG_TEST_RANDOM_GENERATOR=y