ac2515e199
* This switch allows applications to replace lwip with a different IP stack or just make it build if it is a dependency but not actually needed. |
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.. | ||
main | ||
CMakeLists.txt | ||
pytest_udp_client.py | ||
README.md | ||
sdkconfig.ci | ||
sdkconfig.ci.linux | ||
sdkconfig.defaults | ||
sdkconfig.defaults.linux |
Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-S2 | ESP32-S3 |
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UDP Client example
(See the README.md file in the upper level 'examples' directory for more information about examples.)
The application creates UDP socket and sends message to the predefined port and IP address. After the server's reply, the application prints received reply as ASCII text, waits for 2 seconds and sends another message.
How to use example
In order to create UDP server that communicates with UDP Client example, choose one of the following options.
There are many host-side tools which can be used to interact with the UDP/TCP server/client.
One command line tool is netcat which can send and receive many kinds of packets.
Note: please replace 192.168.0.167 3333
with desired IPV4/IPV6 address (displayed in monitor console) and port number in the following commands.
Ref to the upper level README for more information.
Send UDP packet via netcat
echo "Hello from PC" | nc -w1 -u 192.168.0.167 3333
Receive UDP packet via netcat
echo "Hello from PC" | nc -w1 -u 192.168.0.167 3333
UDP server using netcat
nc -u -l 192.168.0.167 3333
Hardware Required
This example can be run on any commonly available ESP32 development board.
Configure the project
idf.py menuconfig
Set following parameters under Example Configuration Options:
-
Set
IP version
of example to be IPV4 or IPV6. -
Set
IPV4 Address
in case your chose IP version IPV4 above. -
Set
IPV6 Address
in case your chose IP version IPV6 above. -
Set
Port
number that represents remote port the example will send data and receive data from.
Configure Wi-Fi or Ethernet under "Example Connection Configuration" menu. See "Establishing Wi-Fi or Ethernet Connection" section in examples/protocols/README.md for more details.
Build and Flash
Build the project and flash it to the board, then run monitor tool to view serial output:
idf.py -p PORT flash monitor
(To exit the serial monitor, type Ctrl-]
.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
Troubleshooting
Start server first, to receive data sent from the client (application).
Running the example for Linux target
This example could be executed on host system, using lwIP port for linux and FreeRTOS simulator on linux. The socket API used in this example directly calls lwIP implementation. Follow the steps below to configure, build and run the example on linux operating system.
- First configure the target (please note that using linux target is currently available only in
preview
stage)
idf.py --preview set-target linux
- Configure the project
idf.py menuconfig
Choose connection capabilities in Example Connection Configuration
menu:
- By default, the
example_connect()
function returns as a no-op, expecting that the connection is already available. This option is preferred when we don't have to interact with outside networking layers and use only lwIP internal interface, such as loopback netif (lo
). - If you want to connect lwIP network interface to the host system networking, set
EXAMPLE_CONNECT_LWIP_TAPIF
.- Configure the interface address information (IP address, GW address and netmask).
- Create a host network interface named
tap0
of TAP type. You can use the./make_tap_netif
script located in thetapif_io
component directory. - Optionally set input or output packet loss rate to simulate loosing data of physical interfaces.
- Note about the host side networking:
- This example uses static IP address configured in
tapif_io
component configuration. - Use the IP ranges that do not overlap with any other IP range of the host system.
- Make sure that the same IP range is configured in
tap0
interface created by tge./make_tap_netif
script. - You can leave the defaults in the script and
tapif_io
settings unless any other host network interface uses192.168.5.x
range. - Read more about host-side networking in the
tapif_io
component documentation.
- Generate partition table for the application:
idf.by partition-table
- Build and run the example the usual way (Note that the flash step is left out)
idf.by build
idf.py monitor