UDP

Bi-directionnal communication with a UDP server/client

Parameters

• Protocol : This is a way to easily parse incoming messages depending on the protocol you chose.

  • Lines : This will consider new data every time a new line character is received. Most Arduino users use new lines as messages split, so it's the default.

  • Raw : If you want to get every byte separately, you can choose Raw, which won't do any parsing of incoming data.

  • Data255 : This will consider new data every time a byte with value of 255 is received. This is a personal and very efficient protocol if you don't care about loosing one byte precision, and only want to send single bytes as it obviously doesn't work for sending float or 32-bit integers.

  • COBS : This is parsing the data accordingly to the COBS mechanism. If you don't know what that is, check out the Wikipedia page.

• Auto Add : This will automatically add values when data is received. Keep it checked if you want to always convert the received data to values, otherwise if you want to only receive some data, uncheck it when you don't wan't to automatically add more values anymore

• Message structure : This decides how every message should be parsed. It depends on the protocol you chose.

• First value is the name : If checked, messages will be expected in the format of 2 arguments : the first one is the name and the second one is the actual value.

• Input : Input allows you to receive data. It's good practice to disable it if your module is supposed to only send data and not receiving any. You will see in the Module list that the "Incoming data" icon is automatically hidden when disabling the Input.

  • Local Port : This is the port on which your external software will send the data.

  • Is Bound : This shows if the port was successfully bound and the module is able to receive data.

  • Receive Frequency : The rate at which to receive the data. Lower frequency will optimize CPU usage and overall performance, but if you receive too much data, you may loose some or not receive it in time, as multiple packets will be processed at the same time.

• Output : Output allows sending data. It's good practice to disable it if your module is supposed to only receive data and not sending any. You will see in the Module list that the "Outgoing data" icon is automatically hidden when disabling the Output.

  • Local : if checked, this will force this output to send to the same computer. It's handy to quickly switch between a remote computer and this computer, to test.

  • Remote host : This is the IP address of the computer to send data to. You need to uncheck Local if you want to specify another address.

  • Remote port : This is the port to send the data to.

  • Is connected : Whether the device is connected or not to the remote. Because UDP doesn't have any packet verification, this doesn't mean that packet sent while this icon is checked will be received in the other end, there may not even be a receiving end !

• Pass-through : This section allows you to directly transfer the incoming data to other Streaming modules, i.e. Serial, UDP, TCP Client and TCP Server. This allow for fast, optimized data transfer through modules, even for data that are not handled by Chataigne.

If you want to test receiving and sending UDP packets, I recommend PacketSender, which is a great free and cross-platform packet testing utility !