I'm Circuit-stupid ... so let's play with electricity!

Overheal

Hello room.

I am in the planning stages for a project I want to project for a summer hobby. Basically, this will be an Arduino-powered birdhouse that will have an internal IR Camera, WiFi & Twitter connectivity, and run off of a solar panel. But, I am circuit-stupid, and roaming the internet of youtube and instructables teaches much but not the specifics I'm getting brainstuck on.

I need help with the circuit design and component selection.]

- The system ought to be fully autonomous. So I am choosing the Arduino Yun for built-in WiFi and a Linux environment on the chip. Technically this could also be accomplished with a Pi but the energy cost continues to go up, and cost of materials isn't that competitive when you factor in the camera, which has to be USB, whereas simpler IR cameras can be wired up to an Arduino. I'm open to sway on this though. Pi power consumption is upwards of 400mAh, the Yun in sleep mode is about 220mAh with nothing connected, other Arduino boards can sleep in the tens of mAh or less. Another option to consider is rigging up this Sleepy-Pi contraption:

http://www.raspberrypi.org/forums/viewtopic.php?f=45&t=47122

If I did that, then technically the Pi need only be powered up for say a minute every hour for the system to take a picture and upload it to the internet and I could just an Arduino Nano to control timing.

- The Power Problem: this is where I'm circuit stupid. I don't know anything about diode selection, voltage regulation, etc. and when you're talking about using solar panels and debating between using NiMh batteries vs. supercapacitors it starts to get confusing. But for instance, this panel looks like it could power the whole project under correct lighting. Most especially if the system is designed to be in a state of sleep/wait 95% of the time, which would give capacitors long enough to charge between actions

http://www.amazon.com/dp/B00HQY56KM/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=O3Y0CQNKVZTM&coliid=I3JPINIEYNVHO7

~580mA supply, 6V, 3.5W

Using rechargeable batteries I feel like you would run into overcharging issues unless you further complicate the circuit with protections and whatnot. Whereas with Capacitors I just need more help with the math figuring out exactly what I need, how many Farads at what voltage basically. On Amazon I've found 2.7V 310F supercaps. So I would need to step down the voltage from the panel to a safe voltage for the caps, then whatever comes from my power supply setup would also have to supply 5V to the project. Ideally the project should first try to get power from the panel, and then when that isn't sufficient, get it from the battery/capacitor.

Where do I begin with this?

Chet T16

I'd get a decent sized LiPoly battery and one of these with the solar panel attached to the input (with 5v regulation if needed)

Power the lot from the battery with one of these. I would imagine you'll find more support available if you use a Pi so rolling your own Sleepy Pi/ nano/pro mini might be an idea

ozmo

Would the maplins solar powered car battery charger be of any use - I have one - its a sort of charge pump thing thats able generate small pulses of power at the correct voltage from very low levels of sunlight and small solar panel. 1.5 Watts.

- usually about 20 euros its supposed to be designed for permanent attachment to the 12V battery for boats and sheds to keep it topped up. There was a larger panel that might be what you need. It doesnt appear to be waterproof however - but works ok from behind glass.

http://www.maplin.co.uk/p/solar-powered-12v-15w-battery-auto-trickle-charger-l58bf

solar power does overcomplicate things though - are you sure some 12v telephone wire strung out to the tree is not possible?

gctest50

These will give 12 / 9 / 5 volt output and run 48v over the CAT5 ( so a few missing volts won't make so much of a difference)

http://www.ebay.co.uk/itm/TP-Link-POE-Power-Over-Ethernet-Adapter-Kit-1-Injector-And-1-Splitter-Included-/360714144549

http://www.tp-link.com/lk/products/details/?model=TL-POE200#spec

not sure how "good" they are though

Overheal

POE is an idea I didn't consider for this project. Good idea though since it doubles functionality and reduces parts costs from wifi. Already bought the initial parts for this prototype it will center around the sleepy pi shield and a pi type A.

I will more than likely end up doing tutorials with the boards for a couple weeks before construction. I also want to do a full run on typical power consumption of the unit. I bought a multimeter along with the shipment, but what's the best way to log current consumption of the project over time?

ozmo

Overheal wrote: »

I bought a multimeter along with the shipment, but what's the best way to log current consumption of the project over time?

You wont be able do it with a multimeter. You could do it using an arduino...

Or for one ready made - something like this?



Link Here

gctest50

A tiny little logger ?

loads out there afaik

http://www.geminidataloggers.com/data-loggers/tinytag-talk-2


https://www.sparkfun.com/products/9530


.

Overheal

The SleepyPi shield I ordered is an Arduino power management board for a RPi - couldn't I have the Arduino measure it's/the project's own power consumption?

Overheal

By the way I'm PISSED because I placed an order for the Sleepy Pi and the company that makes them also has a blog post now about a SPi with an onboard LiPo controller - specifically designed for Solar/Mains + Battery operation -_-

longhalloween

Overheal wrote: »

what's the best way to log current consumption of the project over time?

You could have a dedicated current monitor, but this will be using power too.

You could just estimate current by measuring sleep current and wake current consumption and work out your mAh from that.

Overheal

Overheal wrote: »

By the way I'm PISSED because I placed an order for the Sleepy Pi and the company that makes them also has a blog post now about a SPi with an onboard LiPo controller - specifically designed for Solar/Mains + Battery operation -_-

Talked to the sole proprietor, he needs beta testers for a LiPo addon board that bridges the old and new model. yay