How to use WiFi on particle argon using esp32

[vinilima07]

Hi, i am new on Zephyr.
I have an Argon Nordic Semiconductor nRF52840 SoC with ESP32 Wifi Coprocessor and i am trying to create communication beween then.

Argon Datasheet: https://docs.particle.io/datasheets/wi-fi/argon-datasheet/

I have already established the following network configuration for prj.conf

CONFIG_NETWORKING=y
CONFIG_WIFI=y
CONFIG_NET_IPV4=y
CONFIG_WIFI_ESP_AT_VERSION_2_0=y
CONFIG_WIFI_ESP=y
CONFIG_NET_L2_WIFI_MGMT=y

However, I don't know where to start so that I can issue AT commands to esp32. Sorry for anything but I am very confused with the documentation, so I had to resort here.

[whati001]

Hi @vinilima07

If the esp32 is connected via UART, you can use the Zephyr NetworkManager in combination with the "espressif,esp-at" driver.

The driver define a network device which allows you establish a L2 wifi connection with your AP. After that you can use the normal socket stack to establish a TCP/UDP connection and further a HTTP request or something else.

Please have a look at the WiFi-Shell example. You have to connect the esp32 properly to the nrf uart port and it as subnode. Please find below an example of the devicetree configuration with hardware control flow enabled:

 &uart1_default {
	cts-rts {
		psels = <NRF_PSEL(UART_CTS, 1, 3)>,
			<NRF_PSEL(UART_RTS, 1, 4)>;
	};
};
&uart1_sleep {
	cts-rts {
		psels = <NRF_PSEL(UART_CTS, 1, 3)>,
			<NRF_PSEL(UART_RTS, 1, 4)>;
		low-power-enable;
	};
};
&uart1 {
	status = "okay";
	hw-flow-control;

	esp_wifi: esp-wifi {
		compatible = "espressif,esp-at";
		// power-gpios = <&gpio1 5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
		status = "okay";
	};
};

The final connection should be as follows:

Pin	Nordic	ESP32
RX	P1.01	17
TX	P1.02	16
CTS	P1.03	14
RTS	P1.04	15

After that, you can use the network manager to perform a scan (NET_REQUEST_WIFI_SCAN), connect to an AP (NET_REQUEST_WIFI_CONNECT) and the socket api (socket and connect) to establish a connection.

You can also have a look at this (private) example I have written some time ago to mess around with the esp32 at stack: https://github.com/whati001/zephyr_playground/tree/main/esp32_wifi_http