What would be the best way to control a sprinkler valve and a couple servos simultaneously? What arduino parts/shields would i have to use to integrate the system and control it from an android device?
An Uno should be well able to do what you want.
You dn't need any shield to control servos.
You need to provide a link to the datasheet for the sprinkler valve if you want advice for that. I presume it is an electrcially operated valve.
For control from an Android device have a look at this RemoteXY Thread.
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Information on the sprinkler valve can be found here - http://www.irrigationdirect.ca/PGV\100G-Hunter-1-FIPT-x-1-FIPT-Valve.html
The purpose of the valve is to receive a pulse from the arduino triggering it to open for a certain amount of time. I was thinking a relay would do the trick but what do you think?
I presume this is the valve you mean. Your link is broken.
It seems to have a 24v AC solenoid. The simplest way to control that with an Arduino would probably be with a relay. However an Arduino can't provide enough current for an electromechanical relay and you would need to have the Arduino control a transistor which controls the relay coil current.
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Yeah that's the one!! Sorry about the broken link - Thanks for your suggestions though, I figured that the required current would be a problem 
If you had a suggestion for the model of transistor and/or relay in mind I'm all ears
Derekrw:
If you had a suggestion for the model of transistor and/or relay in mind I'm all ears
Beyond my ability to advise. This Website may help
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It did! I found this really helpful diagram - I attached it below. To my knowledge I believe that I can actually just follow this diagram to the T to get this system working, but I'm still wondering if I would need to put a resistor in series with the power source of the relay in order to regulate it to have a 300 mA current as to trigger the sprinkler valve.
Please don't blame me if the smoke escapes ...
My understanding is that if you connect a 24v AC supply to the solenoid it will work - the internal impedance of the solenoid will be sufficient to limit the current. And NOTE that is an AC supply.
If you are unsure you MUST contact the manufacturer.
When you say "the power source of the relay" I think of the power that is fed into the relay coil. That should NOT come from the Arduino and its voltage will be determined by the specs of you relay. And that power will be quite separate from the solenoid power.
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So if I got a transformer 120V to 24V, plugged it into the wall, then connected that to a 24V relay, then hooked up the 24V relay to the 24V sprinkler valve, in theory that would get the system rolling?
Without further expertise use a relay shield and a 24V power source to drive you 24V sprinkler valve.
Derekrw:
So if I got a transformer 120V to 24V, plugged it into the wall, then connected that to a 24V relay, then hooked up the 24V relay to the 24V sprinkler valve, in theory that would get the system rolling?
Relay descriptions can be a bit confusing because there is the voltage needed to work the coil and, separately, the voltage that is permissible across the contacts.
You need a relay that can handle at least 24v AC across the contacts and 110v or 230v would be fine.
Choose the coil voltage for your convenience. It will need to be driven by a DC power supply because that is easiest for the Arduino and your transistor cisrcuit.
When you say "a transformer 120V to 24V" that sounds like the correct AC output. Just be aware that if the "transformer" includes a rectifier so that it produces 24v DC your sprinkler valve will almost certainly burn out.
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yeah tell me about it, I'm not sure which one to get!!
Oh so are you saying that I am going to need 2 power supplies? 1 for the relay and then a 24 VAC supply for the contacts that will send to the sprinkler valve? I thought that i could use a 24VAC supply to power the relay and when the relay switched it would introduce that power supply to the sprinkler valve....
So if i'm grasping what you're saying right, you're saying that the relay needs to be powered seperately from the power supply being relayed to the sprinkler valve, correct?
You have to power 3 devices:
- sprinkler valve
- relay coil
- Arduino
You can do that from 2 power sources, when either - the relay coil can be powerd from the Arduino source, or
- the relay coil can be powerd from the sprinkler valve source, provided it's 24V DC.
Make up your decision, and find a matching relay (or relay shield or module).
And just to be crystal clear
- the relay coil can be powerd from the Arduino source, or
does NOT mean that the relay can be powered from the Arduino - only that both the Arduino and the relay coil could be powered from (say) a 12v DC source.
and
- the relay coil can be powerd from the sprinkler valve source, provided it's 24V DC.
as far as I can make out your sprinkler valve needs 24v AC
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I understand that much, but doesn't the relay need to regulate the power source for the sprinkler valve? I thought that was the point of it.
For the arduino I figured I'd just totally separately power that, and then I thought it was only an issue of powering the relay as the relay would regulate the power going to the sprinkler valve and shut it on and off.
Derekrw:
but doesn't the relay need to regulate the power source for the sprinkler valve? I thought that was the point of it.
I can't answer because I don't know what alternatives you had in mind when you formulated this question.
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A relay is not a magic device as you seem to assume. It consists of two parts, a switch with one or more contacts, and a coil that presses the switch when powered. That's all.
I apologize for not making my questions more clear, I am fully aware of the functionality of the relay.
When I asked that question I had no other alternatives in mind, I was simply stating that I thought that the relay closed the circuit connected to the sprinkler valve, and therefore would 'relay' the power to the valve. From what I grasp from your explanation though, I need to power the sprinkler valve seperately from the relay. My question was asking if my interpretation of how the relay worked was incorrect - if I power the relay with 24VAC won't it send that power to the valve when it closes the circuit?
Derekrw:
I was simply stating that I thought that the relay closed the circuit connected to the sprinkler valve, and therefore would 'relay' the power to the valve.
That is quite correct
From what I grasp from your explanation though, I need to power the sprinkler valve seperately from the relay.
This suggests that you do not understand that the power to make the relay operate (the power for the relay coil) is entirely separate from the power that is switched by the relay contacts.
For example it is common to use a relay with a coil powered by 5v or 12v to switch dangerous mains voltages. Clearly it is ESSENTIAL to keep the dangerous voltages away from the low voltage side.
Your sprinkler valve seems to work with 24v AC.
Now, there is an entirely separate question - what power supply (volts and amps) is required by the coil in your relay?
I'm sure it is possible to get relays that use 24v AC to operate but that would be a silly choice for an Arduino. Get a relay with a coil voltage that makes it easy for the Arduino to work with - 5v DC or 12v DC would be good choices.
I know it is late to be asking, but are you sure you know the difference between AC and DC ?
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This RC relay enables easy control of large, electrically isolated loads in radio control (RC) systems. The activation threshold and direction are configurable, and a safe-start feature reduces the likelihood of unexpected activation. This assembled version ships with the 5V relay, terminal block, and straight male header pins soldered in, so it can be integrated into hobby RC systems without the need for additional soldering. The included power relay is an Omron G5LE-14-DC5 and is rated for up to 10 A under most conditions.
Thanks,