Arduino Project Circuit Help

[Rishav Guha]

Okay so I'm doing this project based on Arduino(which is a kind of microcontroller). The thing is, I'm a coder and don't really know a lot about the electrical side stuff. So I got a few queries and it'd be really helpful if someone could point me in the right direction

First off, the power supply. It's an outdoor project, so it'd be pretty inconvenient to power it using a ac-dc adapter. So i thought of using a solar panel along with a battery, to keep it working day and night. There are arduinos. the first one takes 5V and upto 1A. The second one takes 3.3V and upto 1A. I also need a diode to prevent the battery from discharging overnight through the solar panels.

The Solar Panel I'm thinking of, is this: Amazon.com: Instapark® NEW All Black 10W Mono-crystalline Solar Panel with 12V Solar Charge Controller: Patio, Lawn & Garden

The output is 10W, with max out voltage=17.5V and max out current=0.57A.

How would I connect this to the arduinos? I thought I could connect the solar panel in parallel with the battery and the arduinos. That way the panel would charge the battery AND provide power during the day, and in the night, the battery would power the arduinos. The diode would prevent the current from flowing through the solar panel.

Is the idea correct?
Also, importantly, where do i place the diode?
which and what kind of diode do i use?
How do I convert the current from the solar panel, to 3.3V/1A and 5V/1A? Using transformers?
And what battery would store the energy most efficiently, and work for at least 8-12 hours without charging?
Could someone please help me out by giving me a circuit diagram and explaining the working to me? Thanks

The other thing I wanted to ask is, how do I use the Arduino(microcontroller) as a switch? As in if I have a High voltage AC Light bulb, or a 1.5v led, how do I make the arduino act like a digital switch? I've tried to research and read about relays, relay drivers and transistors, but couldn't exactly put it together. Can someone please explain a solution to me?


Thanks a lot in advance guys. Appreciate your help a lot. Would be helpful if you could include circuit diagrams

 

[Worcester]

You'll get all the answers that you need (and more) over here: Home | OpenEnergyMonitor

 

[amlu]

question 1 -
use a solar charge controller -
CMP Solar Panel Charge Controller Regulator 10A 12V 24V Volt Protection Function | eBay

something like that for example.
connect your panel into its input (get a solar panel without a controller, just a basic unit)
battery into battery connection
and some load into outputs. you will get 12v dc in there, get dc-dc converter to power your arduino.
LM2596 DC-DC Voltage Regulator + Led Voltmeter Buck Step Down Converter Module | eBay
sealed lead acid battery used for alarms or emergency lighting should do the job... unless you got budget for something better.

use one of digital output pins to drive a relay...

there is a lot of this information on the net. arduino forums, makezine, instructables etc. its all there do your homework please

 

[tazz]

Just drawn this up for you, and hope it will help....solar charging circuit, using 12v SLA battery with 5v output for the micro.
The idea here, is the solar panel charges the battery through the variable regulator. When the current lowers as the battery reaches fully charged state, the the transistor cuts the reg off, preventing the battery overcharging.....The 5v reg will always be supplied off the battery and charging reg. If you want a signal back to the micro, you can disconnect the collector off the transistor, and use it as a pull signal on you mcro, thus tell the input battery has reached fully charge state, with warning overcharging.
Hope this helps.
View attachment Solar Charger.pdf

 

[Worcester]

@tazz, thanks for that.

What range of panel specs can you run that off? Max / Min Voltage and Max current?

 

[tazz]

The question is, how long will it take to charge the battery.....if solar panel actually gives a constant current of 0.5 amps, then over 8 hours of daylight it should charge a 4a/h battery in therory. The ouput can also be no higher than 500mA....all in all cannot see you getting many hours out of this unless you draw less current or you put micro in sleep mode when not in use.
By the way pm your details, as I am always looking for ATMEL compliers for logic switching in security/fire applications.