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pesor / TTGO-T-HIGrow

The extremely good plant sensor named LILYGO TTGO-T-HIGrow, is here integrated into Home Assistant, via MQTT messages, that can be Autodiscovered, via the belonging Python program. The program supports both DHT sensors, the new BME280 sensor and the external soil temperature sensor.
https://github.com/pesor/TTGO-T-HIGrow
MIT License
70 stars 35 forks source link

In code remarks You're wondering what "Salt" is #13

Open wagnerohz opened 3 years ago

wagnerohz commented 3 years ago

The sensor measures the conductivity of the earth between the two shiny silver buttons. This is an indication of the amount of dissolved salts that the plants need as food. These values can only be approximations. And they only make sense if the soil is moist. The limit values for "needed", for example, seem to me to be set too high. I measured once:

This is not a criticism of your magnificent work, just a (perhaps) helpful addition.

pesor commented 3 years ago

Yes the salt figure is a tricky part.

The tap water here in Denmark is filled with calcium, at my House the DH is > 26, the salt measurement in clean tap water in a glass is approx. 200.

It is possible in uservariables to set the salt levels, so that it comply with your needs.

I actually did an (not released yet) addition to the salt issue, where the figure was divided with the soil level/100, and a treshold for when calculation should start, eg >60% soil.

It is giving me a division be Zero error sometimes, so I will look into it, and add it to next release.

I am currently working on a special HIGrow Lovelace card, but that is to be in a much later release.

Also there is a bug in the measurement, as it is done with DC current and not AC current, this means that the measurement will detoriate over time, if you do not make sure that your watering flushes the sensor.

The DC current organise the ION's so that they are placed in ION- to one side and ION+ to the other side, which makes the measurement going toward zero.

//Per

wagnerohz commented 3 years ago

Thank you very much for the detailed engagement with my reflections. Yes, we have 6-7° DH here in my place in northern Germany. Now I understand why the threshold values in your code are suggested so high. Thank you for the important hint with the "sorting" of the ions at the anodes. I had also noticed that the values dropped faster than my test plants could "drink". I will observe the flushing of the sensor.

I am very curious about your next releases.

//Christian

pesor commented 3 years ago

Hi Christian.

I have been working with a better presentation of the most important data from the sensor.

As I wrote I am trying to make a Lovelace card, but I have at this moment an intermidiate solution you might like.

I did send this to Bearded Tinker, with whom I communicate a lot.

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This is the latest on my TTGO-HIGrow sensor output for my plants.

I have put development of a better card on hold, as I have too many things on my hand at the moment, so I figured this is a good intermediate solution.

I have included a screen shot, and the code for the “Drivhusplanter”, which is the most comprehensive.

Here are the HIGrow info.

[cid:6C21789F-894D-4A77-A1F4-83F47C5CEE5D]

Here are the code:

type: entities title: Drivhusplanter entities:

You need to install card-tools.js, and secondaryinfo-entity-row via HACS, read more here: https://github.com/custom-cards/secondaryinfo-entity-row

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Best regards, Per