Still did not find a way to extract the temperature value from the payload with the debug node. Tried several things with http://jsonpath.com/ without success. There I could only select count and data if I reduced the last line into: "data": {"count":"15323","temp":19.19} or similar.
PAYLOAD
{
"gatewayEui": "008000000000A050",
"nodeEui": "02012902",
"time": "2016-01-04T11:36:18.37989Z",
"frequency": 868.3,
"dataRate": "SF12BW125",
"rssi": -43,
"snr": 10,
"rawData": "gAIpAQIAAQAGXkYoenjKdblP3oQ57pD2e6StzfulMUxmxsvJjUpFBULzQg==",
"data": "{\"count\":15323,\"temp\":\"19.19\"}"
}
PS: Guess I have to add JsonPath node to my node-red installation to parse the payload so I can send the temperature value with UDP to my HA installation