When receiving 't' via a serial port, Leo transmits some data via the port in the format of a space-delimited string, "elapsedSeconds△Celsius△humidity△hectopascal".
#include <Adafruit_BME280.h> boolean gotInitData = false; unsigned long initTime; float elapsedSeconds; Adafruit_BME280 bme; void setup() { Serial.begin(115200); bme.begin(); } void loop() { while (Serial.read() == 't') { if (!gotInitData) { initTime = millis(); gotInitData = true; } elapsedSeconds = (millis() - initTime) / 1000.0; Serial.print(elapsedSeconds) ; Serial.print(" "); Serial.print(bme.readTemperature()) ; Serial.print(" "); Serial.print(bme.readHumidity()) ; Serial.print(" "); Serial.print(bme.readPressure() / 100.0); Serial.println(); } }