Automatic Irrigation System

[Krimstix]

Hello. I'm new to this forum and I really need your help. I have this system here:

And the site I got it from: http://www.electronicshub.org/automatic-plant-irrigation-system/

My problem is that I don't know if the two portleft-r is both connected to the hex inverter. If so, what pins are they connected. Also, what is the recommended voltage of the other capacitors since it was never given.

Lastly, do you think this will work?

PS: I tried using MultiSim but I am just an amateur so I don't know what I did wrong. If you could post a screenshot of your simulation I would really appreciate it.

Thanks a lot.

PPS: please move my thread if it is in the wrong section. I'm just new here.

 

[Harald Kapp]

Imho this is not a good circuit and the operations are not well explained on the web site.
Here's an example of a much simpler system with a suitable explanation.

Or put "automatic irrigation system circuit" into your favorite search engine's input box.

 

[CDRIVE]

Imho this is not a good circuit and the operations are not well explained on the web site.
Here's an example of a much simpler system with a suitable explanation.

Or put "automatic irrigation system circuit" into your favorite search engine's input box.

I like that. It includes a soil image embedded in the schematic!

Chris

 

[Krimstix]

What is the 2M2 resistor? 2.2megaohms?

 

[Harald Kapp]

What is the 2M2 resistor? 2.2megaohms?

Yes, this is a common notation to avoid decimals:
2M2 = 2.2 MΩ
2k2 = 2.2 kΩ
2R2 = 2.2 Ω

 

[Krimstix]

What is the "diode" looking symbol above R1?

 

[Harald Kapp]

I suppose it is an LED to indicate operation of the circuit (lit when relay is on)

 

[Krimstix]

I tried running it using Multi Sim, but there is no voltage output from the IC.

What do you think is the problem?

Note: The variable resistor signifies the soil while the lamp signifies the pump.

 

[CDRIVE]

Your Vcc (V1) polarity is reversed.

Chris

 

[CDRIVE]

Upon a second look I'd also increase the value of Pot R1 to 5KΩ. This is to insure you can swing pin2 (Trig) low enough to trigger the 555. Off the top of my head I believe the 555 triggers (Output pin High) when this voltage (Vtrig) goes below 1/3rd of Vcc.

Chris

 

[Harald Kapp]

As R1 is there to simulate soil resistance, gor for MΩ values (dry earth).

 

[CDRIVE]

Good point Harald. In that case he may want to increase the value of R3 (1KΩ) too.

Chris

 

[CDRIVE]

Krimstix, please get in the habit of using multiple GND symbols instead of running a GND buss all over your schematics. It'll make your schematics much easier to follow. It will also reduce schematic errors. Generally we like to see the positive ( + ) supply rail on the top of the page and negative ( - ) on the bottom of the page. GND symbols can be anywhere but pointing down is SOP.

BTW, all your voltmeters are connected backward. In Spice they'll just display a negative voltage. If this was 1960 you'd be pinning your analog meter below zero. It would be sitting right on the lower vane stop because that would be as far as it could go.

Chris

 

[Krimstix]

Good sirs, I tried replacing the soil resistance and R1 and V1 and the multimeter and it showed this:

It still won't work .

 

[Bluejets]

V1 not going to ground anywhere for the 555 supply.

 

[Krimstix]

Please help. I need this for my school project.

 

[CDRIVE]

You're not complying with the replies you've received. If you used GND symbols the way I told you to you wouldn't be making these schematic errors. You also didn't use the (Trig Pin) resistor recommendations either.

You're also a very bad boy because I can usually spot a school project (that belongs in the "Homework" section) by the first post. No gold star for you!

Chris