Soil moisture/ EC/ Temp sensors

Would you add your PCB’s to kitspace.org

It might help make them discoverable. It’s just a Yaml file and a pull request: GitHub - kitspace/kitspace: A place to share electronics projects

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Maybe Acorn could gather up sensor data from these as it trundles by

Oh! I used something like this at home for my gardening system! The really nice thing about them is they’re capacitive rather than resistance based so don’t tend to have bare metal showing. That means they don’t rust so they’re great for outdoors!

I was hoping to try put one onto some sort of multi-tool that an arm or carriage could hold at some point then you wouldn’t need one for every pot or plant. Since they’re so small and lightweight they’re kind of perfect for it too.

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I think they have quite limited life in the soil? I seem to remember corrosion gets to them in around a year or so. Perhaps a version with removable electronics that you could swap to a new probe would be an improvement from an e-waste perspective. The probe could just have some pins for your swappable electronics module?

I think you could make these loRa enabled easily enough too, but if the bot is trundling by anyway maybe BluetoothLE is good enough.

ah, I didn’t realize they had a short lifespan, that’s a massive shame. I feel like parts that require replacing super regularly aren’t really worth using, that’s so much waste haha

I wonder if you could improve it but just putting them in soil and removing them after taking the measurement.

Do you know what makes them corrode? I thought it was just the ones with bare copper plates that died quickly

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It looks like the main issue may be the edges of the PCB which enables water to get under the solder mask: https://medium.com/@d.robertson/protecting-capacitive-soil-moisture-sensors-e1ab81f1c4fb

Nail varnish or similar might help?

That article is super interesting! Its kind of impressive how in-depth it is haha. Its a shame the author never posted the results from their changes after a year or so just to see if it lasted or not.

It would be fun to see how far all of that could be taken, especially if someone tried their hand at making a proper fully resilient board from the get-go.

I might end up trying to do this to my current ones and put a message here on my results :slight_smile:

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I’ve had some fun playing with Miflora sensors, having Lux/ Temp/EC available is nice.

Not open hardware though.

Many years ago I had a Edyn which was actually really nice until they pulled the plug on the cloud server and turned it into instant e-waste.

An open hardware version of the Miflora, With the Solar panel of the Edyn & LoRa would be a nice bit of kit…

Seems like open hardware LoRa ones already exist Search - soil

oh nice! Yeah if that was open source that would be a perfect little collection of sensors. Did you find the miflora lasted well?

Not bad actually. I was actually mostly using it as a tank water level sensor. So suspended above an aquaponics tank, Home assistant sending me a warning email if the moisture level went nuts.

For outdoor/polytunnel use I protected them with a bit of clear plastic tube over the top, then folded over and cable tied. They are not waterproof by default.

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