This flow will start you off. You will need to edit the sensor it is looking for. Output the result from the sensor to the emoncms MQTT server - no topic should be specified as it is set in the function.
I’ve included one ‘get_entities’ node, but as you can see, you can suck up numerous sensors in one go and process through the same function.
[{"id":"87789c210eb269e7","type":"inject","z":"085dd5ac6c2fac91","name":"30s","props":[{"p":"time","v":"","vt":"date"}],"repeat":"30","crontab":"","once":true,"onceDelay":"10","topic":"","x":110,"y":140,"wires":[["0b14af28d48c3798","61d7368ff63c5d86","82406eaf5b6f2b11","60055d4fa834c880","e244b665c825591d","32ef84b3caf86610","7dc0b93208c9978a","4c2da82ccdf5f9b0","295c9e993bc52f21"]]},{"id":"295c9e993bc52f21","type":"ha-get-entities","z":"085dd5ac6c2fac91","name":"sensor.ble_temp TS*","server":"9bb65ffe.1998d","version":0,"rules":[{"property":"entity_id","logic":"starts_with","value":"sensor.ble_temperature_ts","valueType":"str"}],"output_type":"array","output_empty_results":false,"output_location_type":"msg","output_location":"data","output_results_count":1,"x":380,"y":180,"wires":[["8cd55d75b2ff2414"]]},{"id":"8cd55d75b2ff2414","type":"function","z":"085dd5ac6c2fac91","name":"Process data for sending","func":"let newmsg = {};\nnewmsg.payload = {};\nvar reptext = \"\";\n\nnewmsg.topic = \"emon/sensor\"\n\nif (msg.hasOwnProperty(`Data_Source`)) {\n newmsg.topic = newmsg.topic + \"/\" + msg.data_source;\n} else {\n reptext = msg.data[0].entity_id.split(\"_\",1)[0] + \"_\"\n newmsg.topic = newmsg.topic + \"/\" + msg.data[0].entity_id.split(\"_\",1)[0].replace(\"sensor.\",\"\")\n}\n\nmsg.data.forEach((element, index, array) => {\n if (!isNaN(element.state)){\n newmsg.payload[element.entity_id.replace(reptext,\"\")+\"_state\"] = Number(element.state);\n // newmsg.payload[element.entity_id.replace(\"sensor.\"+reptext,\"\")] = Number(element.state);\n }\n});\n\nnewmsg.payload.time = Math.trunc(msg.time/1000);\n\nreturn newmsg;","outputs":1,"timeout":"","noerr":0,"initialize":"","finalize":"","libs":[],"x":790,"y":280,"wires":[["7ca692f481d4a99c"]]},{"id":"9bb65ffe.1998d","type":"server","name":"HassIO","version":5,"addon":true,"rejectUnauthorizedCerts":true,"ha_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true,"heartbeat":false,"heartbeatInterval":30,"areaSelector":"friendlyName","deviceSelector":"friendlyName","entitySelector":"friendlyName","statusSeparator":"at: ","statusYear":"hidden","statusMonth":"short","statusDay":"numeric","statusHourCycle":"h23","statusTimeFormat":"h:m","enableGlobalContextStore":true}]
If you wanted to, you could filter the get entities node on device_class: temperature and that will pick up all sensors with that device class.

However, be careful, I found I had 58 temperature sensors (in HA terms) in my setup!