Moisture sensor showing 100%

[fpy-homeb]

I have installed following instructions When running example script provided with ether 1 or 2 sensors attached, the result returns 100% moisture This is on a pi zero w2.

I will re-run from a fresh install of bullseye to see if anything changes (this will be the 2nd time around)

Has anyone else had this issue?

[leon-anavi]

Hi @fpy-homeb,

Could you please share the following details:

• Is the soil moisture sensor properly connected to the dedicate 3pin male header? Could you please share a photo? GND to GND, VCC of the sensor to 5V and AOUT from the sensor to Signal on ANAVI Gardening uHAT.

• Are you using Raspberry Pi OS?

• Is SPI enabled? https://github.com/AnaviTechnology/anavi-docs/blob/master/anavi-gardening-uhat/anavi-gardening-uhat.md#enable-spi

• Are you running the soil-moistore-sensors.py example? Could you please share a few lines from the output for a reference.

Best regards, Leon

[fpy-homeb]

Hey @leon-anavi

Thank you for quick reply

Yes spi is enabled

pi@PlantSensor:~/anavi-examples/anavi-gardening-uhat/soil-moistore-sensors/python $ python3 soil-moistore-sensors.py Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 %

Yes running the above script

I am controlling via ssh is that an issue?

Thanks

[leon-anavi]

OK, the wiring looks good and SPI is enabled...

pi@PlantSensor:~/anavi-examples/anavi-gardening-uhat/soil-moistore-sensors/python $ python3 soil-moistore-sensors.py Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 100 %

Are both sensors connected at the moment what this was logged? What happens if only one of the sensor is connected or if there are no sensors at all?

I am controlling via ssh is that an issue?

No, login via SSH is totally fine and actually recommended.

Thanks, Leon

[fpy-homeb]

When no sensors are connected:

pi@PlantSensor:~/anavi-examples/anavi-gardening-uhat/soil-moistore-sensors/python $ python3 soil-moistore-sensors.py Soil Moisture Sensor 1: 0 % Soil Moisture Sensor 2: 0 % Soil Moisture Sensor 1: 0 % Soil Moisture Sensor 2: 0 % Soil Moisture Sensor 1: 0 % Soil Moisture Sensor 2: 0 %

When 1 sensor is connected:

pi@PlantSensor:~/anavi-examples/anavi-gardening-uhat/soil-moistore-sensors/python $ python3 soil-moistore-sensors.py Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 0 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 0 % Soil Moisture Sensor 1: 100 % Soil Moisture Sensor 2: 0 %

[leon-anavi]

Hi @fpy-homeb,

So do I understand right that basically no matter which of the 2 sensors you plug it always shows 100% and if there are no sensors attached it is 0%?

These capacitive soil moisture sensors provide analog output which is converted to a digital value by MCP3008 ADC (analog-to-digital converted) after that soil-moistore-sensors.py maps the value to a percentage with function valmap https://github.com/AnaviTechnology/anavi-examples/blob/master/anavi-gardening-uhat/soil-moistore-sensors/python/soil-moistore-sensors.py#L33 The default range is between 3.5V and 5V but may be in your case due to a different environment is should be adjusted to cover larger range: https://github.com/AnaviTechnology/anavi-examples/blob/master/anavi-gardening-uhat/soil-moistore-sensors/python/soil-moistore-sensors.py#L80

Best regards, Leon

[fpy-homeb]

Hey Leon,

Sorry life got in the way, thank you for pointing me to this.

I have updated the script to read (sensor1, 5, 1,0,100), 0) And out of a fluid i am still getting a reading of 38% and in water I'm getting 87%

Soil Moisture Sensor 1: 38.0 % Soil Moisture Sensor 2: 87.0 % Soil Moisture Sensor 1: 38.0 % Soil Moisture Sensor 2: 87.0 %

I'm guessing I can't go higher than 5 as the pi is limited to 5v? Or lower than 0V?

Thanks for you help

[leon-anavi]

Hi @fpy-homeb,

I'm guessing I can't go higher than 5 as the pi is limited to 5v? Or lower than 0V?

Yes, that's correct, the range is between 0V and 5V. Probably a tuning within that range is required in your environment to adjust the minimal value in this range that maps to 0V.

Best regards, Leon

[fpy-homeb]

Brilliant thank you!

Ill have a play and see what i can make work

[leon-anavi]

Please, later on, drop a line about your findings because they will be useful as a feedback for other people in the community going through the same process of tuning the mapping range.

Thanks, Leon

[fpy-homeb]

So after a few hours of testing and some basics maths.

My settings are 4, 1.5. This results in a range of 1% to 100% which i can live with.

Hope this helps other moving forward.

I'm also looking at updating a copy of the example script to pull into InfluxDB, if you like i can post that once i have finished as well?

[leon-anavi]

@fpy-homeb,

Thank you for taking the time to share the feedback. Yes, it will be great to have an example script for InfluxDB in future.

Btw you can submit a Crowd Supply field report about your finding for the voltage range in your environment and get $25 Crowd Supply credit as a reward :) For details please have a look at: https://www.crowdsupply.com/field-reports

Thanks, Leon