UDP Request response

README.md

Simple udp request and response flow

flow.json

[{"id":"9457cf66.6ba83","type":"udp out","name":"","addr":"127.0.0.1","iface":"","port":"1881","outport":"","base64":false,"multicast":"false","x":710,"y":174,"z":"b91431a8.46ebd","wires":[]},{"id":"9b8de31f.64722","type":"function","name":"MQTT-SN sender","func":"// Takes a payload and topic and makes a QoS -1\n// MQTT-SN message buffer out of it.\n\nfunction makeMqttsBuffer(topic,message) {\n    var buf;\n    var p=0;\n    var len = topic.length + message.length + 7;\n    if (len > 254) {\n        p=2;\n        buf = new Buffer(topic.length + message.length + 7 + p);\n        buf[0] = 1;\n        buf[1] = parseInt((len+p)/256);\n        buf[2] = parseInt((len+p)%256);\n    }\n    else {\n        buf = new Buffer(topic.length + message.length + 7 + p);\n        buf[0] = len;\n    }\n    buf[1+p] = 12;\n    buf[2+p] = 96;\n    buf[3+p] = parseInt(topic.length/256);\n    buf[4+p] = parseInt(topic.length%256);\n    buf[5+p] = 32;\n    buf[6+p] = 32;\n    for (var i = 0; i < topic.length ; i++) {\n        buf[7+i+p] = topic.charCodeAt(i);\n    }\n    for (var i = 0; i < message.length ; i++) {\n        buf[7+topic.length+i+p] = message.charCodeAt(i);\n    }\n    return buf;\n}\n\nmsg.payload = makeMqttsBuffer(msg.topic, msg.payload);\nmsg.type = 'sender';\nreturn msg;","outputs":1,"x":346.00000381469727,"y":274.00003147125244,"z":"b91431a8.46ebd","wires":[["ea88865c.157778","122ef430.edd10c"]]},{"id":"34c90cb5.cb36f4","type":"inject","name":"","topic":"Hello","payload":"Dave","payloadType":"string","repeat":"","crontab":"","once":false,"x":170.00002670288086,"y":287.9999952316284,"z":"b91431a8.46ebd","wires":[["9b8de31f.64722"]]},{"id":"ea88865c.157778","type":"debug","name":"","active":true,"console":"false","complete":"true","x":732,"y":337,"z":"b91431a8.46ebd","wires":[]},{"id":"a43fe2e7.5bc02","type":"udp in","name":"listener","iface":"","port":"1881","datatype":"buffer","multicast":"false","group":"","x":130,"y":370,"z":"b91431a8.46ebd","wires":[["f6434c89.09bcb"]]},{"id":"f6434c89.09bcb","type":"function","name":"MQTT-SN receiver","func":"msg.type = 'receiver';\nreturn msg;","outputs":1,"x":425,"y":367,"z":"b91431a8.46ebd","wires":[["ea88865c.157778"]]},{"id":"122ef430.edd10c","type":"delay","name":"","pauseType":"delay","timeout":"2","timeoutUnits":"seconds","rate":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":529,"y":230,"z":"b91431a8.46ebd","wires":[["9457cf66.6ba83"]]}]