Multiple I2C or RS485 probes on the Edison

[WFlie1]

Hey Guys,

I`m planning an irrigation project using Intel Edison with the Arduino Breakout Board. I`m considering using the Arduino IDE.

Goal is to irrigate about 10 pots with plants of different sizes on my balcony. Every pot will be equipped with an individual soil moisture probe and an individual water connection using a solenoid valve. Wiring of Sensors and valves will be over a distance up to 5m. Water is provided by a small pump in a loop.

I`d like to use the following capacitive sensors: https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/ https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/

There is also an RS485 version and an analog version available.

Advantage compared to the more common resistivity-based probes is that the probes don`t have direct contact with the soil and the measurement is not effected by variable ion concentration in the soil.

Does anyone have experience in connecting this number of probes to the Edison? Which bus (I2C, RS485, Analog) should I use considering cable length and connectivity to the Edison? I`m prefering a digital connection where possible. From what I`ve been reading, there are problems connecting multible I2C slaves an there is no documentation doing the same using RS485.

Thanks for your help!

[Pedro_M_Intel · Accepted solution]

Hello wiesenflieger,

Edison does not have an RS485 interface, so at least of communication is not available to be used with this sensor. However, I2C and analog are indeed available. If you would like to use several slaves I'd suggest you to read http://electronics.stackexchange.com/questions/135078/multiple-i2c-slaves-on-intel-edison-i2c-6-bus Multiple I2C slaves on Intel Edison I2C-6 Bus. If you would like a digital connection it would be your best option.

In case you would like to use a different approach using mraa, you could use the Grove Moisture Sensor. It has a UPM library available with a tested example, which you can find in https://github.com/intel-iot-devkit/upm/blob/master/examples/c%2B%2B/grovemoisture.cxx upm/grovemoisture.cxx. Just in case you would like to consider another option.

Peter.