Powering an Arduino in a car

[Tim Moses]

I recently bought a bus and am about to add an Arduino to act as a monitoring/warning system. Do any of you have suggestions for getting clean power for an Arduino off the starter batteries? A secondary purpose may be to power a USB hub to act as a phone charging station. I'd like to avoid going DC to AC to DC.

This is what I'm considering at the moment.
http://www.opussolutions.com/product/164/DCA5_080_512__80W_.html

The bus already had a website, so I haven't really posted any pictures of it. Here is the site from when it was originally converted. There are some differences since then and it is a little more worn, but is still in great shape.
http://www.skewly.com

--
Tim Moses - Sitemason <http://www.sitemason.com/>, 615-301-2600 x138
The Sitemason Content Management System allows you to control and distribute content to your website, social networks, blogs, mobile sites, and iPhone apps. Need a content management check-up? Go to http://www.sitemason.com/survey

[Jay Gmail2]

Is that the actual but? Wow that's cozy!
The Opus looks great, 5V and 12V and plenty of current with other
sleep options. You could power up the arduino on the 12V terminal and
light up the whole bus with led arrays with the 5V at 8Amps!
The usb charging car adapters I've known to output 4.5V only and the
Arduino needs at least 6V. I found several sites with DIY circuits but
there are many already tried, tested and standardized automotive power
supplies for you and your safety. I did find this, cheaper and easier
to connect:

http://www.mindkits.co.nz/store/tools/power-supplies/car-adapter-power-supply-7-5vdc-3a

-Jay

[Tim Moses]

That's the actual bus. I pulled out the couches and put in coach bus seats with seat belts to fit all the children. I had it checked out and a few things fixed, but it is in pretty good shape and it is very solid. There is nothing flimsy on the chassis. Everything is steel. I'm wearing out drill bits and making good use of the angle grinder.

My problem now is just keeping up with the state, levels, and/or temperature of all the systems: 2 fresh water tanks, gray water tank, black water tank, starter batteries, house batteries, shoreline, generator and its gas tank, engine and exhaust temps, and proximity warnings for backing up, passing, parking, going under low bridges or over potential tank-scraping bumps. Also, the state of any of the 11 doors and hatches on the outside would be great to know. The potential for adding cool control panel lights and switches is phenomenal!

The first order of business is an automatic checklist for takeoff. I already drove off without unplugging the shoreline. Fortunately, the plug popped out without damage, but that could have been bad. The plan is to check for shoreline power and check if the battery/plug compartment door is closed. When the ignition is on, either of those two should light a big warning light. I'll add to it from there.

Wow! Thanks, Jay. I often miss the obvious. A regular car adapter would make a lot more sense for getting started and I have them sitting around. I can get a fancier DC - DC power supply later. I was also trying to figure out how to detect the voltage on the AC shoreline and looked at some expensive parts. I eventually realized, I don't care about the voltage. I just need to know if there is power. A leftover wall wart plugged into the bus AC will tell me that and that's easy to detect with the Arduino. I can start on this tonight!

I may still go with the Opus later. The ultimate plan is to buy one or more cheap Android tablets to act as a digital dashboard. Using the web server library on the Arduino and Webkit on the Android, I can display and control anything I need to and it will look really impressive doing it. For that, I'll need some more power.

--

Tim Moses - Sitemason <http://www.sitemason.com/>, 615-301-2600 x138

The Sitemason Content Management System allows you to control and distribute content to your website, social networks, blogs, mobile sites, and iPhone apps. Need a content management check-up? Go to http://www.sitemason.com/survey

[Andrew Duthie]

It seems like the Opus is designed to power a full PC, not something
small and simple like an Arduino. Forgive my beginner-level question,
but is the Arduino really all that sensitive to the input voltage
fluctuations? A vehicular 12V battery should give 12.6 with the
vehicle off, about 9-10V with the starter motor cranking, and 14-15V
with the alternator running. Assuming the rectifier in the alternator
isn't broken, there is perhaps a 0.1V AC component to the battery's
output.

Working from memory, the Arduino's voltage regulator can work with
anything from 6V up to 24V, right?

If you want to see a killer school bus project, by the way, take a
drive up Forrest Ave. in east Nashville, between 14th and 16th St.
Can't miss it. (Red and white, with a chopped van serving as a...
loft? towards the rear of the bus.)

-Andrew

On Dec 6, 11:55 pm, Tim Moses <t...@moses.com> wrote:
> I recently bought a bus and am about to add an Arduino to act as a monitoring/warning system. Do any of you have suggestions for getting clean power for an Arduino off the starter batteries? A secondary purpose may be to power a USB hub to act as a phone charging station. I'd like to avoid going DC to AC to DC.
>

> This is what I'm considering at the moment.http://www.opussolutions.com/product/164/DCA5_080_512__80W_.html
>
> The bus already had a website, so I haven't really posted any pictures of it. Here is the site from when it was originally converted. There are some differences since then and it is a little more worn, but is still in great shape.http://www.skewly.com

[Tim Moses]

The Arduino may be able to handle it, but based on random un-credible Internet postings, powering other things would be less risky using a DC - DC changer. What's the risk with hooking it up directly, blowing the Arduino, shorting to other systems through the Arduino? I don't really know.

The Opus is definitely overkill for just the Arduino, but would kind of solve the problem once and for all for whatever I might want to hook up later.

I actually met the guy who owns that bus. He works at Pep Boys on Charlotte and helped me out when I was looking for parts.

--
Tim Moses - Sitemason <http://www.sitemason.com>, 615-301-2600 x138

[Jared Cluff]

I recommend taking a line off the 12v power.  Put a 9v regulator on it.  Put a fuse and a capacitor in the circuit - fuse to keep the power from frying the arduino in the event of a power surge, capacitor to keep the power levels constant and then feed the arduino the 9v of power and up during the startup of the bus, if the bus drops power to the 12v cigarette lighter during startup.