AD7747 and Arduino Nano

Other Hardware Sensors
1

Hi there,

I am working on a mini-project where i would like to use a capacitance sensor to detect the presence of rainfall/intensity of rainfall and then output a PWM signal dependent on the intensity of the rainfall. I have already got the Arduino Nano and an AD7747 evaluation board. I have made a button sensor on flex PCB which i have tested using the software which comes with the AD7747 and it can detect the presence of water on a windscreen as the capacitance increases. This is the extent of that software so that is where the arduino comes into play.

I am now sorta stuck as I have not used i2c nor an arduino before and i am attempting to connect the evaluation board to my Nano and read the value of capacitance from the board. I know that I need to connect wires on the evaluation board from LK2 to appropriate places on the arduino however i am a noob when it comes to this area (Do i connect it to a digital pin or analogue pin?). I am wondering if anybody has used this evaluation board or similar ones (AD7745/6) and knows first of all how to connect up these two components and then read the value of the capacitance into the arduino from the board? any code would be appreciated

After this, I intend to conduct a series of tests on the windscreen with different levels of water to come up with the values of intensity which trigger different levels of PWM output from the arduino.

2

We strongly recommend that beginners start with the example projects that come with the Arduino IDE (the software development package), in order to learn the language and special features of the Arduino. If you don't, expect endless frustration.

Try googling "Arduino AD7747" to find tutorials.

3

Get the Arduino cookbook and read it. Also on line there are many videos etc showing the Arduino and how to do what you want. This additional information will go a long way in getting your problem solved.

4

Attach the board to Arduino Nano as shown in figure 4. from datasheet evaluation AD7747 PCB. On Arduino Nano, SCL is output at A5 pin and SDA is output at A4 pin. Connect them to Ev.board. SCL to SCL, SDA to SDA. Set the Vcc voltage to 5V and connect the ground too. My software is freely available for you.