How to use ESP-NOW in zephyr?

[NineDayCC]

Discussed in #61055

^{Originally posted by NineDayCC August 2, 2023}
Does zephyr support ESP-NOW? I found ESP-NOW deivers in hal_espressif, but I didn't find any APIs or Kconfig options to enable ESP-NOW.
Is there any way to use ESP-NOW in zephyrOS?

[ndrs-pst]

Hi, @NineDayCC.
After reviewing the soc/xtensa/espressif_esp32/esp32/default.ld in Zephyr repository, I'm concerned that Zephyr does not yet support ESP-NOW.

This is because I couldn't find libespnow.a, which is located in the hal_espressif repository, referenced in the linker script.
This omission suggests that ESP-NOW might not be integrated into Zephyr for the ESP32 platform.

Another aspect we need to consider is whether libespnow.a is independent of the ESP-IDF platform or not.

ping @sylvioalves 👀

[rhvarrier]

@sylvioalves is there any plan to add support for esp now on zephyr?

[bhuvanchandradv]

Hi all,

Following up on this discussion — I've submitted a PR that adds a working ESP-NOW sample for Espressif ESP32 boards:

PR #108332

The sample (samples/boards/espressif/espnow) demonstrates:

• WiFi STA init + fixed-channel lock (no AP required)
• esp_now_init() with broadcast peer registration
• RX callback with RSSI, source MAC, and decoded heartbeat payload
• Beacon thread broadcasting a 14-byte heartbeat at a configurable interval
• Build-time role selection: SENDER / RECEIVER / BOTH (default : useful for two-board loopback)

Tested on esp32_devkitc/esp32/procpu (WROOM) with two devices talking to each other. Builds clean for esp32, esp32s3, and esp32c6 targets via Twister.

One thing worth noting for anyone working on this area: CONFIG_WIFI_ESP32 currently Kconfig-selects NET_L2_WIFI_MGMT -> NETWORKING -> NET_IPV4, which drags in the IP stack even though ESP-NOW never touches it. The sample works around this by minimising net buffer pool sizes. This is a known structural limitation in the Espressif WiFi Kconfig; a proper fix would need to decouple NET_L2_WIFI_MGMT selection from the raw WiFi blob init path.

Happy to address review feedback. If there's an existing tracking issue for ESP-NOW support I should link to, please let me know.

[NotPubi]

I just learned about zephyr and want to port my codebase but i need espnow, thanks for doing this. I don't understand what you said the problem and solution is, so hopefully it works out.