Outdoor plant moisture sensor with solar

Projects General Guidance
1

Hello,
I’m new here and I am new with esp/arduino.

I want to build a system like this: Solar-Powered ESP32-C6 Balcony Soil Moisture Monitoring - DFRobot Maker Community

I want to use 4 sensors and a p-mosfet to save power.

I make a fritzing (tm) for the hardware part. Can anyone have a look and tell me, „may it work“

Here is the fritzing:

IMG_6626
IMG_66261179×1243 133 KB

Sorry for my bad englisch and thanks for your help
sysTim

2

Do you have the exact same hardware as in the tutorial? (The panel’s power spec and the ESP board matters).

If so - yes just using more sensors connected to the relevant pins will be fine. Of course the code will need to be adjusted.

Hard to read your mosfet wiring in the Fritzing - but there are tons of tutorials on how to wire a transistor- just make sure it’s adjusted to your needs (driving from a 3.3V board)

3

From your link:

Designed for short-term indoor plant monitoring and educational projects

So that's a problem.

4

Fritzing can also make real schematics. Please do that and post it. Please ensure that the pin names and component values are legible on your schematic (not like your diagram).

5

Depending on the MOSFET it might.
Are you using the Sparkfun sensors or the DFRobot sensors.

6

Hello Paul,
my Plants are on a small Balkony with good "Home-Netzwork" and i know, i need a case and other waterproof things:-)

7

No, the sensors on the Picture are only "Placeholders", my fritzing hasn't the right parts.
I want to use kapasitive sensors from Amazon (AYWHP-Bodenfeuchtesensor-Hygrometer-Kapazitive-Feuchtigkeitssensor)

I found them in another reference Project (Anleitung DIY Feuchtigkeitssensor für Gartenbewässerung Bausatz Homematic - technikkram.net) (German)

8

Some are using I2C so your wiring wouldn’t be right for those - they woukd sit on the bus.

9

@J-M-L

Thanks for the hint, in the Amazon description, they write: "Pins: Analoges Signalausgang, GND, VCC."; so i think its analog

10

here is the schematic (the really first schematic in my life), thanks for your help

esp32-c6-p_Schaltplan
esp32-c6-p_Schaltplan2273×970 107 KB

11
  1. I think the battery should be connected to both the battery +/- pins.
  2. The PV panel can be connected to Vin, Gnd, but check that your ESP board can accept at least 9V on the Vin pin, because the panel will probably be more than 6V in direct sunlight and when little current can flow from it, for example when the battery is full.
  3. When drawing a schematic, use as many Gnd and 3V3 symbols as you need, close to each component or group of components that needs them, to avoid having those wires snaking all over the schematic, making it harder to read.
  4. Your TO220 size MOSFET may be overkill for this purpose. The sensors will draw less than 150mA in total. There are probably some TO92 size MOSFETs that can handle comfortably more than that.
12

What MOSFET do you plan on using?

13

@jim-p
I want to use a BS250p

BS250P.pdf (48,2 KB)

14

@PaulRB

  1. You are right.
  2. The Board has an internel LoadBalancer, especially for Solar-Panels at Vin.
  3. I made a new Version, is it now better to read?
  4. I change the TO220 to an TO92 (BS250P)

Thanks for yor help.

Bodenfeuchte V2_Schaltplan-final
Bodenfeuchte V2_Schaltplan-final1394×972 56.5 KB

15

Yes, that's better.

Your next task is to make a prototype, ideally on breadboard or if you don't like breadboard, solder up on to protoboard or stripboard. Don't rush into designing a PCB before you have tested your prototype.

The BS250P has a minimum resistance of 14 Ohms. In your circuit it may be more than that, I'm not sure. This resistance may affect your sensor readings a little, but they are not very precise sensors anyway, so I do not think this will be a problem.

16

So a VP0106N3-G would be better?

VP0106_P.pdf (748,9 KB)

17

No, very similar.

18

OK, if all the components are here, i made a breadborad test.
Thanks for your help.

19

That won't work at all.

20

@systim
No that is also no good.
You need a MOSFET that has a low RDs(on) at -3.3V or lower. Although I doubt that you will find one in a through hole package.
I recommend you use this: