I want to do a level sensor for my own by using:
- copper strips on a thin plastic glass
- Arduino UNO
The issue is that I am not really familiar with I²C communication since it is the first time I work with that. Therefore, by finding documentations on internet and in the datasheet, I wrote a code to communicate with my AD7747. The code is actually working but it always displays 8.20...pF and it seems that whatever I do, the measured capacitance does not change at all.
About the application of my level sensor, when I measured manually the capacitance between the two plates, it varies from 5pF (Low level) to 35pF (High level), the level I want to reach is situated around 20pF so I was wondering how to "calibrate" the AD7747 so I can obtain this kind of measurement from my chip: 20pF +- 8pF ?
- 20pF is my wished level and the variation (+-8pF) is the full range of the chip.
To help you understanding what I did, please find in attachment a wiring diagram of my sensor and the code I wrote. About the picture, I know it is written AD7745 on it but I currently use the AD7747, the latter was not available in the library of the program I used.
I hope that someone can answer me or provide me a code that I can use to finish my level sensor.
Is it possible to get the resolution to this thread. I am stuck with the same issue as stated above and would like to know how to resolve the code to read the capacitance accurately.
Is your query the same what these guys have?