NPK sensor for microcontrollers

hello every one

i just wondering is there any NPK module out there that i can integrate with microcontroller? doesn't has to be exactly accurate, at least can tell is the soil contains good enough NPK substance. i read a few article, including using light reflection with photodiode, haven't tried that yet, but soon i will. so is there any other method/ reference i should have read first?

Thanks in advanced

I wouldn't think such a device exists. Normal NPK analysis requires three different chemical tests with disposable reagents after each. I can't think of any electrical way to do it as all of NPK influence conductivity and pH to some degree. I'm no expert in this so perhaps someone has more experience.

Brian.

teralytic is advertising a soil probe monitoring multiple parameters including NPK. The sensor operation principle isn't mentioned in any publication I have seen yet. It may be ion-sensitive electrodes, if they can actually work in in-situ without suspending the soil in water seems questionable to me.

FvM said:

teralytic is advertising a soil probe monitoring multiple parameters including NPK. The sensor operation principle isn't mentioned in any publication I have seen yet. It may be ion-sensitive electrodes, if they can actually work in in-situ without suspending the soil in water seems questionable to me.

Click to expand...

betwixt said:

I wouldn't think such a device exists. Normal NPK analysis requires three different chemical tests with disposable reagents after each. I can't think of any electrical way to do it as all of NPK influence conductivity and pH to some degree. I'm no expert in this so perhaps someone has more experience.

Brian.

Click to expand...

yes, i think there is some journal i've read that use conductivity methode to determine NPK value, i just don't have the related data. i'll do more research, may be i'll post in this thread if i found out

FvM said:

teralytic is advertising a soil probe monitoring multiple parameters including NPK. The sensor operation principle isn't mentioned in any publication I have seen yet. It may be ion-sensitive electrodes, if they can actually work in in-situ without suspending the soil in water seems questionable to me.

Click to expand...

nice info, i also confuse why there is a cheap device like https://www.aliexpress.com/item/2016-new-Gardening-tools-2-in-1-Soil-PH-meter-fertility-tester-with-3-Probes-Ideal/32696850938.html?spm=2114.search0104.3.2.29fa3deaYScB1y&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_5017611_10059_10696_100031_10084_10083_10103_451_452_10618_10307_5017711,searchweb201603_56,ppcSwitch_4&algo_expid=cf6728a8-2961-4224-8edc-d10ee475d28a-0&algo_pvid=cf6728a8-2961-4224-8edc-d10ee475d28a&priceBeautifyAB=0

it also doesn't use watering, only use dry electrode, may i'll buy that one and see what it can do. i know it's only measure fertility, but some say it has something to do with NPK, i am no expert also in this one