Stepper motor actuated datalogger with temperature/humidity sensor.
This datalogger records the input from an Adafruit_TCS34725 color sensor, the temp/humidity from a DHT-compatible thermometer, and the time/date from RTC DS1307 clock. The data is recorded at given intervals and then written to an SD card and sent to the thingspeak website for online viewing. I was able to easily power the device for a couple of days on battery, taking recordings every couple of hours.