Difference between revisions of "QTouch for Water Level Sensing"
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In the code used, a reference measurement is made at the setup (start) and the LED or anything are triggered if the measured value jumps to a value higher > 15. Again of course, touch or coming close to the wires, of even changing their positions will heavily affect the measurement. so to recallibrate the tube needs to be empty, press reset and it's ok again. One could think of a self-calibrating code, analysing the difference and direction of the change in the measured values. | In the code used, a reference measurement is made at the setup (start) and the LED or anything are triggered if the measured value jumps to a value higher > 15. Again of course, touch or coming close to the wires, of even changing their positions will heavily affect the measurement. so to recallibrate the tube needs to be empty, press reset and it's ok again. One could think of a self-calibrating code, analysing the difference and direction of the change in the measured values. | ||
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| + | == Testing with shielded wires == | ||
| + | |||
| + | coming soon... | ||
== Code Examples on Github == | == Code Examples on Github == | ||
https://github.com/dusjagr/QTouchADC/tree/master/examples | https://github.com/dusjagr/QTouchADC/tree/master/examples | ||
Revision as of 12:11, 1 April 2015
Contents
1 Sensor: Continous Setup
Below you see some measurements using the QTouchADC capacitive sensing to monitor water level in a tube. During the measurement, I raise the level of the water in discret steps and then let it empty again. In the last part I physically touch my laptop or/and the wires between the arduino and the electrodes. The capacitive sensing seems to be ok to measure the water level from the outside, but of course there is major errors when you touch anything near the cables aswell. hmmmm... maybe shielded wires?
Having the electrode inside the tube gives me a much larger reading and less noise, but is not always wanted or possible in a real world setup.
Non-contact electrodes are mounted on the outside of the tube on both side, one connected to the QTouch.sense channel the other to GND.
Much more noise is present the laptop is plugged in and connected to the main power.
2 Sensor: Ring Setup at 2 different Levels
In this second setup, i tried to use 2 channels of the QTouch capactive sensing to measure the passing of the water level at specific positions on the tube. A steel wire was wrapped around the tupe as a ring, one on the very bottom is connected to GND, 3-4 cm above is a first ring and on the top part a second one.
In the code used, a reference measurement is made at the setup (start) and the LED or anything are triggered if the measured value jumps to a value higher > 15. Again of course, touch or coming close to the wires, of even changing their positions will heavily affect the measurement. so to recallibrate the tube needs to be empty, press reset and it's ok again. One could think of a self-calibrating code, analysing the difference and direction of the change in the measured values.
Testing with shielded wires
coming soon...
