By using a DHT22, a SD card, and
I made a temperature and humidity data logger.
Step 1: Connecting DHT22, Inserting SD Card to InvIoT U1
To connect the DTH22 with U1 you need 3 wires.
Two wires are the power wires and the 3rd is the 'one wire' connection
For the 'one wire' connection I am using the D2 pin of the U1. You can edit the code and use any other pin you like, except the D4, which is used for the SD card.
Make sure you don't use the 3rd pin of the DHT22.
DTH22 ---------> U1
Pin#4-------> D2 digital pin 2
No Pull up resistor is needed to run the DHT22
Step 2: Upload Sketch
Insert FTDI232 to U1 and connect it to your PC.
Upload the sketch with the arduino IDE at file->examples->invIoT->applications->TempLogger
Step 3: Getting Log File From SD to a Spreadsheet
Power of the U1 and remove the SD card.
Copy the file to your computer to make your log graph.
I include a file with a demo temperature and humidity from my house.
Participated in the
Circuits Contest 2016