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1  Community / Exhibition / Gallery / Outpost. Remote Pan/Tilt Android Camera Application on: February 18, 2014, 01:55:47 am
Here's my Arduino project:

http://www.gundabah.com/Outpost/index.html

It's been up and running for a couple of years now. Deployed out in the elements on a farm in Australia, but I monitor it remotely from here in Silicon Valley. It's a great way to keep an eye on things.
2  Using Arduino / General Electronics / Re: Using my Arduino board to "drive a pin low" on my external DC/DC converter. on: November 26, 2012, 03:56:32 am
Hey! It works.

Always nice when that happens.
3  Development / Other Hardware Development / In search of an ADK board with DC/DC converter on: November 25, 2012, 09:29:55 pm
I have an "Iteaduino ADK" board that took over 3 weeks to get to California. Somehow it got fried tonight and will not respond to input voltage.

http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120411005.html

I need a replacement urgently. I can't wait another 3 weeks for this thing to be shipped from Hong Kong to New York, where it waiting in customs for 2 weeks, before finally arriving.

The reason why I bought this board was that it had 2 things I couldn't find on any other board: Android ADK USB accessory mode compatibility and a low power consumption DC/DC converter that accepted 7-23V. My project is driven by an Android phone and it is solar powered from a 12V SLA battery, so the regulator power supplies on other boards draw too much.

Anywhere I could get something like this in a hurry would be great because I am due to fly overseas to install the project next week.

Thanks!
4  Using Arduino / General Electronics / Re: Using my Arduino board to "drive a pin low" on my external DC/DC converter. on: November 19, 2012, 09:41:35 pm
Thanks for both replies. That was reassuring and informative.
5  Using Arduino / General Electronics / Using my Arduino board to "drive a pin low" on my external DC/DC converter. on: November 19, 2012, 08:48:44 pm
I need some basic guidance to make sure I am not about to fry my electronics. It is about how to "bring a pin low" on an external board.

I have an Arduino project with two servos that rotate an Android phone, which is in turn driven remotely by another Android phone (See photos). I use a separate DC/DC converter to power the servos. The input to the Arduino board and to the separate DC/DC converter is a 12V battery. The project is solar powered, needs to run 24x7x365 on top of a power pole in another country and therefore needs to be very reliable and not draw much power. I am finding that occasionally one of the Hitec servos - the digital one - gets in a funk where it sits there without moving and with no load on it yet draws 700mA. If I command it to move a bit, it goes back to the idle power usage or around 8mA. But I can't afford to risk the high power usage scenario.

Fortunately, my DC/DC converter, http://www.pololu.com/catalog/product/2110, has a feature that enables the output to be turned off. This is perfect. Here is the description:

Quote
The EN pin can be driven low (under 0.3 V) to turn off the output and put the board into a low-power state that typically draws 150 μA. The board has a 100kΩ pull-up resistor between EN and VIN. The EN pin can be driven high (above 2 V) to enable the board, or it can be connected to VIN or left disconnected if you want to leave the board permanently enabled.

I can see the EN pin. My question is, do I connect that pin to one of the digital outputs on the Arduino board and the ground on the input of the DC/DC converter to the ground of the Arduino board? Do I use one of the PWM digital pins or another one? I am a newbie to circuit boards and signals, so pardon my ignorance, but will there be a conflict between the 5V (I assume) output of the digital pin and the 12V input voltage of the DC/DC regulator.

I am using the Iteaduino ADK, http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120411005.html, which took 4 weeks to arrive from Hong Kong, so I'd like to be sure before I fry something.
6  Development / Other Hardware Development / Re: What are the differences between the Iteaduino boards? on: October 02, 2012, 09:32:39 am
Unfortunately I have limitations: Power and reliability.

The whole thing will be outside in the weather on a remote farm location 24x7. There is no power or internet connection available. I have to power it via a solar panel / charge controller / lead acid battery. I already have one Android prototype that has been running this way successfully for months (See attached). Low power is important so I don't want either the board or the phone using a Bluetooth connection.

It has to be 100% reliable. The unit will be atop a high hill, exposed to high winds and only reachable with 2 people and a tractor platform. I can't have it needing to be reset. Therefore I don't like wireless connections where something might get reset. I want a physical cable for commands.
7  Development / Other Hardware Development / Re: What are the differences between the Iteaduino boards? on: October 01, 2012, 08:46:55 pm
Thanks everyone. I need to control it from an Android device, so I am *Guessing* the ADK one is the most suitable...
8  Using Arduino / Motors, Mechanics, and Power / Re: How much current can an Arduino board supply? on: October 01, 2012, 08:39:39 pm
I thought the Iteaduino has a DC/DC converter, not a regulator, and that it takes the supply voltage down to 5V. That's why I was looking at it. I thought that should take care of the heat issue?

That question aside, I heed your comments about running servos off a board. I see lots of people doing it and am wondering whether it is more a prototype to prove it *can* be done rather than whether it *should* be done. This thing is going to be outside 24x7 and located miles away from people. It needs to be rock solid. Oh, and the whole thing is going to be solar powered as well.

I have to have the phone running off the Arduino board because it is going to be driving the board in USB host mode, but it needs to be charged be the board at the same time.
9  Development / Other Hardware Development / What are the differences between the Iteaduino boards? on: October 01, 2012, 07:43:32 pm
I see there is the

Iteaduino
Iteaduino Leonardo
Iteaduino MEGA 2560
Iteaduino ADK
Iteaduino BT

I don't see the significant differences between them in terms of what you would use one for over the other. Can anyone point them out for me?
10  Using Arduino / Motors, Mechanics, and Power / How much current can an Arduino board supply? on: October 01, 2012, 07:39:56 pm
I want to power and Iteaduino board from a 12V battery.

I want the board to charge my Android phone (300mA), as well as power a Hitec HS-5485HB servo (Standard size, digital, 400mA@4.8V no load) and a Hitec HS-485HB (Standard size, analog, 150mA@4.8V no load)

Can the board do this on its own?
11  Using Arduino / Project Guidance / Re: Solar powered Arduino and Android: Possible? on: October 01, 2012, 03:02:02 pm
Pylon, thanks for all the feedback. One question and one observation:

1. I acknowledge your point about possibly needing an external DC/DC converter for excess load. That product you pointed out, Mean Well  PSD-15C-05, has an input voltage of 36V. Can you recommend one that accepts a 12V input?

2. On the Android current, I actually measured the current yesterday drawn from a 12V 5Ah battery to charge a Samsung Galaxy S2 that was dead flat. It drew 277mA for 3.75 hours, after which the current gradually fell off over the next 45 minutes until it because fully charged, at which point it stopped drawing current. Picture attached.
12  Using Arduino / Project Guidance / Re: Solar powered Arduino and Android: Possible? on: September 28, 2012, 08:27:28 pm
Interesting. I just learned that attachments do not display to people who are not signed in...
13  Using Arduino / Project Guidance / Re: Solar powered Arduino and Android: Possible? on: September 28, 2012, 05:39:28 pm
I have attached a basic drawing of what I am trying to achieve. Can the 12V battery supply power to the Arduino, the Arduino power the phone yet the phone control the Arduino?
14  Using Arduino / Project Guidance / Re: Solar powered Arduino and Android: Possible? on: September 28, 2012, 04:59:49 pm
Pylon, thank you for the excellent advice. I am a software guy so the straight up fact about regulating vs. converting was really useful. On that subject, for optimal efficiency, am I best to use a 6V lead acid battery? Most of the panels, charge controlling systems and batteries are 12V, so that is the simplest way to go on the supply side, but is the DC/DC converter to take 12V down to 5V as efficient as taking 6V down to 5V? I lack the electrical background.

The first servo I am looking at powering is the the Hitec HS-5485HB. It will be in this servo powered gearbox: http://www.servocity.com/html/spg5485a-360_360o_rotation.html

The specifications say it is a digital servo (I haven't even looked up the implications of that yet...), with an operating voltage of 4.8-6V, 8-9mA idle and 400-500mA no load operating. The specifications are here: http://www.servocity.com/html/hs-5485hb_servo.html. Can this be powered directly from the Iteaduino?

The second servo is the Hitec HS-485HB. Lower consumption at up to 180mA: http://www.servocity.com/html/hs-485hb_servo.html

So that means with both servos running concurrently, the power consumption could be 680mA.

But then there is the phone. Back to my original question, can the power come in from an external supply to the board and the servos, but also be charging the phone, which is controlling the board?

If it can, great. Then with the board at 100mA and the phone at up to 500mA, that could be 1280mA total. I wonder if the board can accept that much current?
15  Using Arduino / Project Guidance / Solar powered Arduino and Android: Possible? on: September 28, 2012, 10:10:25 am
I want my Android phone to control servos connected to an Arduino board, but the power source for everything must be a solar panel connected to a 12V or 6V lead acid battery.

Can this be designed to work?

If will be located permanently outside all year round.

I already have an Android phone powered by a solar panel and 12V battery. That has been running outside now for 3 months. Now I need to add servos controlled from the phone.

I am new to Arduino, so I am still trying to understand how the charging works, power consumption of the board and servos at idle etc, accessory/host mode, what boards and shields will be required etc.
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