Hi.. I'm looking for some advice not sure if this is the best forum to ask but..
My project is a home monitoring system. Ultimately will display temp, relative humidity, and whatever else I can think of. Looking for suggestions on how to implement a cheap Arduino to Arduino network over distances of 20 meters or so. RS422? Extended I2C?
I constructed a capacitive level sensor to monitor water level at the sump pump out of CPVC pipe and copper strips. It tests out very well, shows 45 pf dry and over 200 pf with a meter of water surrounding. Now need an Arduino sketch to measure capacitance in that range with maybe ten percent accuracy. Must be temperature stable as the sensor is in an area of the home that is warm but not heated (crawl space). I'm looking at Paul Badger's CapSense library and also several web pages on doing the 63% charge measurement method. I'm a little scared of CapSense for long term absolute measurement as it appears to do self calibration frequently. Would like to hear from people who have implemented these techniques and can comment on how stable they are over time and temperature.
