1.. zephyr:code-sample:: cellular-modem
2   :name: Cellular modem
3
4   Use a cellular modem to communicate with a UDP server.
5
6Overview
7********
8
9This sample consists of a simple application which powers on
10the modem, brings up the net interface, then sends a packet
11with pseudo random data to the endpoint test-endpoint.com,
12which is a publicly hosted server which runs the Python
13script found in the server folder. DNS is used to look
14up the IP of test-endpoint.com.
15
16Notes
17*****
18
19This sample uses the devicetree alias ``modem`` to identify
20the modem instance to use. The sample also presumes that
21the modem driver creates the only PPP network interface.
22
23Setup
24*****
25
26Start by setting up the devicetree with the required
27devicetree node:
28
29.. code-block:: devicetree
30
31   /dts-v1/;
32
33   / {
34           aliases {
35                   modem = &modem;
36           };
37   };
38
39   &usart2 {
40           pinctrl-0 = <&usart2_tx_pa2 &usart2_rx_pa3 &usart2_rts_pa1 &usart2_cts_pa0>;
41           pinctrl-names = "default";
42           current-speed = <115200>;
43           hw-flow-control;
44           status = "okay";
45
46           modem: modem {
47                   compatible = "quectel,bg9x";
48                   mdm-power-gpios = <&gpioe 2 GPIO_ACTIVE_HIGH>;
49                   mdm-reset-gpios = <&gpioe 3 GPIO_ACTIVE_HIGH>;
50                   status = "okay";
51           };
52   };
53
54Next, the UART API must be specified using ``CONFIG_UART_INTERRUPT_DRIVEN=y`` or
55``CONFIG_UART_ASYNC_API=y``. The driver doesn't support UART polling.
56
57Lastly, the APN must be configured using ``CONFIG_MODEM_CELLULAR_APN=""``.
58