I'm building a project with a standard 5V Arduino that has got a few quite standard analog sensors such as temperature and accelerometer. I'm also going to use the cellular shield from Sparkfun .
I need this setup to be powered with solar cells, and since this is a new thing to me, I need some advice in what cell and battery to use.
I might add that the arduino + cellular chip can be put in sleep mode to heavily reduce energy consumption. The way the application works is that it "sleeps" most of the time and wakes up about every 10-20 minutes to make a reading and send it off in an SMS, then goes back to sleep.
The cell shield only uses around 2mA in sleep mode, but bursts up to 2000mA when sending an SMS. So I imagine my battery would need to have an mA rating of at least ~2200mA.
So I'd love to tips and pointers on what hardware to use, this is what I've found so far. Ideas?
2 x 3.7V Li Ion batterys
1 x 1.3 Watt 10 Volt solar panel
(Apparently I'm not allowed to post links in this post since I'm new in this forum, I'll try to post them follwing in this thread, if I'm trusted to do that??)
Any size limitations on the setup? To possibly save $$$ you might want to look at getting a solar lighting system that has the batterys, solar panels, and charging system already setup as a power system (see link below). There are very efficient and inexpensive switching power regulators that can be used to reduce ~12v down to the typical logic levels.
@zoomkat Thanks for the link. Yes, i do have size and weight limitations, this setup will be mounted on the back of a bike so we don't want the whole setup to go much above a pound or two. Also, the solar panel would need to be waterproof.
try using a 5v Solar cell otherwise you have to burn the voltage from 12v to 5v for the arduino.
I got a setup working with solar cells. 3x 250mA 5v with an 4Ah battery works great even in winter 24h / 365days a year.
Got the Sparfun LiPo loader:
I might add that the arduino + cellular chip can be put in sleep mode to heavily reduce energy consumption. The way the application works is that it "sleeps" most of the time and wakes up about every 10-20 minutes to make a reading and send it off in an SMS, then goes back to sleep.
Can you please share the skeleton of your sketch ? I have similar requirement where I want my Arduino to sleep for most of the time, but wake up at specific time(s) in future and perform some task and go back to sleep. I am new to processing, so any references or sample code will help. I am not interested in the logic/details but just the program structure.
If you use lithium cells you'll need a lithium charger/protection circuit (otherwise they might catch fire...) Consider NiMH instead. Your high burst-current requirements suggest high-spec'd batteries with solder tabs.
Also you can get lithium packs with built-in protection and charging circuitry, which would do fine if rated for the current (RC battery packs are spec'd for high current note...)
I too am looking for a solar solution. It's an outdoor system that needs to remain outside.
I have sufficient space on my deck where people can't get at it, but I'd like to be able to have some sort of communications on the unit to talk to my computer wirelessly.
I currently have a solar panel that is almost 16V, and I'd like to use that. I have high school electronics under my belt a thousand years ago, but I'm pretty good with this stuff. But I do have questions. Voltage differences usually get me.
Is there a way to pull current from batteries 24/7 while charging them? That would push the same voltage across the full circuit, I'm thinking.
I have a 12V solenoid that I might use to control a rain barrel outflow for a garden I am designing. Essentially I want an Arduino to open the valve at various times of the day. I might want to have the Arduino send the height of the water to my computer somehow. Not sure how to do that.
But, first off, I'd like to design a solar power system with a battery for the Arduino.
Any ideas? I'm sure this is simple for those with more training than myself.