Here is a known-good flow that uses the BME280.
Note that the reformat function node simplifies the format of the data for display or passing to another system.
[{"id":"a9e889ba.6422f8","type":"tab","label":"Flow 2","disabled":false,"info":""},{"id":"9a2db7f1.dd5a18","type":"debug","z":"a9e889ba.6422f8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":730,"y":160,"wires":[]},{"id":"e6ccffec.3de5a","type":"function","z":"a9e889ba.6422f8","name":"reformat for IBM Watson","func":"//var pres = msg.payload.pressure_hPa.toFixed(2);\n//var tempC = msg.payload.temperature_C;\n//var tempF = msg.payload.temperature_F;\n//var humidity = msg.payload.humidity;\n\nmsg.payload = {\n BarPress: msg.payload.pressure_hPa.toFixed(2),\n TempC : msg.payload.temperature_C.toFixed(2),\n TempF : msg.payload.temperature_F.toFixed(2),\n Humid : msg.payload.humidity.toFixed(2),\n Status : msg.payload.switch\n};\n\n//test with a constant string\n//msg.payload = {BarPress: \"1000.00\"};\n\nreturn msg;\n//\n// temperature_C: 24.54\n// humidity: 48.00285972066518\n// pressure_hPa: 1008.9618686461673\n// model: \"BME280\" \n// heatIndex: 25.624424558111855 \n// dewPoint_C: 12.810600563041554 \n// altitude_M: 35.74196949170104\n// temperature_F: 76.172 \n// pressure_Hg: 29.79463137918758","outputs":1,"noerr":0,"x":530,"y":160,"wires":[["9a2db7f1.dd5a18"]]},{"id":"dbed9420.59b608","type":"Bme280","z":"a9e889ba.6422f8","name":"BME280","bus":"1","address":"0x76","topic":"bme280","extra":true,"x":329,"y":200,"wires":[["e6ccffec.3de5a","f6fc599a.dcb008"]]},{"id":"bf205802.36d808","type":"inject","z":"a9e889ba.6422f8","name":"Trigger BME data","topic":"","payload":"","payloadType":"date","repeat":"10","crontab":"","once":true,"onceDelay":0.1,"x":150,"y":200,"wires":[["dbed9420.59b608"]]},{"id":"f6fc599a.dcb008","type":"debug","z":"a9e889ba.6422f8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":730,"y":200,"wires":[]}]
