{"id":394203,"date":"2024-06-29T11:28:08","date_gmt":"2024-06-29T11:28:08","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=394203"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=394203","title":{"rendered":"Sending data from Arduino Nano 33 IoT to Raspberry Pi 4 using UDP<\/span>"},"content":{"rendered":"
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Goal<\/strong>: continuously send UDP packets from an Arduino Nano 33 IoT to a Raspberry Pi 4 to understand the reliability of this solution.<\/p>\n

It\u2019s not important at the moment<\/strong>: software or networking performance, throughput, etc. This is a first test to check the basics, there is a lot of room for improvements in the code, protocol, approach, which will be done in future iterations and based on the discoveries done in this test.<\/p>\n

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The experiment<\/h3>\n

From the Arduino, an UDP packet is sent to the Raspberry Pi. The packet contains a string with the value of an incremental counter, and the value of\u00a0micros().<\/p>\n

Contents of the first 3 packets were (one per line):<\/p>\n

1,33726393 2,33728539 3,33730495<\/code><\/pre>\n
On the Raspberry Pi<\/strong>, netcat<\/strong> is listening for those UDP packets:<\/p>\n
$ netcat -u -s 0.0.0.0 -p 4545 -l > netcat-output.txt<\/code><\/pre>\n
  Once finished, the last lines of netcat-output.txt<\/strong> were: <\/p>\n
$ tail netcat-output.txt  1799991,3579137145 1799992,3579139114 1799993,3579141112 1799994,3579143035 1799995,3579144985 1799996,3579146918 1799997,3579148832 1799998,3579150780 1799999,3579152790 1800000,3579154958<\/code><\/pre>\n
and the output see on the Arduino console<\/strong> shows partial stats and the final stat:<\/p>\n
(...) stats | iter=1797000 | err=9285 | msg\/sec=507 stats | iter=1798000 | err=9285 | msg\/sec=507 stats | iter=1799000 | err=9285 | msg\/sec=507 stats | iter=1800000 | err=9285 | msg\/sec=507 ENDED | Sent 1800001 UDP packets in 3545431 ms. with 9285 errors<\/code><\/pre>\n
Errors<\/h3>\n
How the errors are counted? The return value of WiFiUDP.endPacket()<\/strong> is used: that method returns 0 if there was some error. See WiFiNINAUDPEndPacket<\/a>  for mor information.<\/p>\n
On the Raspberry Pi, we can easilly check how many packets were actually received: <\/p>\n
$ wc -l netcat-output.txt 1790712 netcat-output.txt<\/code><\/pre>\n
Results<\/h3>\n