Code for multiple soil moisture sensors

RE: Code for multiple soil moisture sensors

dougw — Thu, 27 Dec 2018 07:16:12 GMT

You could also measure the water depth with a single capacitance sensor:

Keysight Technologies U1282A Digital Multimeter - Applications - Water Level Sensing

Texas Instruments FDC2214 Capacitance to Digital - Review

An arduino can measure capacitance using just 2 wires and a resistor.

RE: Code for multiple soil moisture sensors

luislabmo — Thu, 27 Dec 2018 06:26:53 GMT

Hello Izz,

This Arduino example is probably the starting point to learn how to read Analog input with an Arduino and then using the serial as output.

Then, use the serial info produced by the arduino to build the excel with your computer, few options that come to my mind:

Processing
Use the Parallax Data Acquisition tool:
- One example here
- Another example

Good luck.

Luis

RE: Code for multiple soil moisture sensors

izzrahim — Thu, 27 Dec 2018 03:18:11 GMT

Okay Thanks. I know nothing about Arduino and coding, can I ask for your assistance to help me with the coding (sketch), what to be included, what are the loops, basically how to get 6 analogs in a code.

I'm doing this experiment of measuring volumetric water content in a one meter cylinder, and I'll be placing six soil moisture sensors inside the cylinder... later i will introduce water on the top and I need to measure (obtain readings) the water content in the cylinder at different height. And these readings are to be taken for 24 hours period: I need to have all six readings (since you mentioned that it cant be done simultaneously, therefore a gap of 0.1 ms should be fine) every five minutes.

thanks for the explanation.

RE: Code for multiple soil moisture sensors

mp2100 — Wed, 26 Dec 2018 14:57:22 GMT

Izz,

How flexible are you for solutions (budget and programming language)? If Arduino is required, you’ll be limited by the memory of the computer, very few data points can be saved. You could use an add-on SD memory card shield. For example:

https://www.adafruit.com/product/1141

Using that, you can file writing to the SD memory card. If you are moving this into Excel, I use the simplest format, a CSV file, write each data point to the SD card with a comma between each value.

RE: Code for multiple soil moisture sensors

dougw — Wed, 26 Dec 2018 07:50:35 GMT

An arduino typically cannot read all channels simultaneously. Analog channels can be read sequentially with about 0.1 ms between readings. For moisture readings this would normally be sufficient.

To make an arduino system that can read analog channels simultaneously requires external sample and hold circuitry or external A/D converters.

Could you explain why you need simultaneous sampling in case there is a better way to achieve your requirement?