In this project, I am going to demonstrate to you how to log data from LM35 temperature sensor values to an SD card and store it as CSV file, with the help of the idIoTware shield.
We are using LM35 temperature sensor to monitor the temperature. The idIoTware shield has a built in, on board, LM35 sensor.
- The sensor has a sensitivity of 10mV / oC.
- We use a reciprocal conversion factor, that is 100 oC/V.
- The output voltage varies linearly with temperature.
- The general equation used to convert output analog voltage (Vout) to temperature is:
- Temperature ( oC) = Vout * (100 oC/V)
- So if Vout is 0.5V , then, Temperature = 50oC
However on the idIoTware shield, the LM35, temperature sensor is wired such that with a higher temperature we get a higher Analog Voltage on PIn A0.
This example shows how to log data from LM35 temperature sensor to an SD card using the SD library.
In this example we have created a CSV file with the temperature values every one minute for 15 minutes. This interval rate and duration is configurable. If there is existing file, then it will create new file with different name.
Once we upload the code in Arduino, you need to test the temperature sensor data on the serial monitor. It's time to keep the device in some place where you want to collect the temperature data for day or even month!
Once you copy the csv file from sd card.you can plot the temperature graph using excel software.
No more connecting leds to breadboard and messy wiring. With the idIoTware shield the sky's the limit.