Show Posts
Pages: 1 2 3 [4] 5
46  Using Arduino / Project Guidance / Re: Arduino to control switches on: March 29, 2011, 08:57:08 pm
That's an interesting thought, I will try painting on of the peltier elements black and giving it a go with the single line detector, however a problem looms, the Peltier element's cold side will be facing the ground (so when it turns off the water will melt into the collection vessel), so to detect ice the single line detector would have to be below it, and would be subjected to a downpour of water. I'm not sure if I can waterproof this because I assume any lense I put around it will alter the IR signal.
47  Using Arduino / Project Guidance / Re: Arduino to control switches on: March 28, 2011, 09:55:55 am
Is there a manual for that FET switch? Or is it one of those things that are fairly standard to operate? If so is there a tutorial on this?

Quote
As to the ice on the peltier you might look at an optical way to detrmine frost buildup

Can the Arduino perform such image analysis? I'm looking to make this totally Arduino based so a camera to a desktop is a bit of a no go. I am open to other ideas however.
48  Using Arduino / Project Guidance / Re: Arduino to control switches on: March 28, 2011, 07:51:49 am
Terry what search criteria did you use?
49  Using Arduino / Project Guidance / Re: Sensing for someone in the room on: March 27, 2011, 09:42:10 pm
Do you need an Arduino to accomplish this? I would just use a wifi camera and do some image processing on a desktop.
50  Using Arduino / Project Guidance / Re: WiFi Robot Project on: March 27, 2011, 09:37:30 pm
The use of the FOSCAM WiFi Cam is a good idea, I have one that I am using for this purpose and it works like a treat. Also very easy to reverse engineer the protocol and input it all into the one base station (and record the footage).

Weighs about 250G and about uses about 350 mA for me.
51  Using Arduino / Project Guidance / Re: Indoor GPS-like tracking - how could it be done? on: March 27, 2011, 09:34:36 pm
SkyHook can do indoor positioning quite accurately (and the accuracy increases with more WiFi base stations you have in the area).
52  Using Arduino / Project Guidance / Re: Arduino to control switches on: March 27, 2011, 09:05:22 pm
OK here is a clearer explanation of what I am trying to achieve.

Firstly I want to dehumidify the air into water (or ice in this case). To do this I am using a peltier element. I will need to be able to switch this element on and off via the Arduino (hence the need for a programmable switch). I will need to measure the weight to know when the peltier has collected enough ice to be turned to water (switching the peltier off will immediately cause the ice to heat up and fall into the water collection tank.

Secondly, I want to convert the water to oxygen and hydrogen via electrolysis, I will need to measure the water level to make sure their is enough water to submerge the electrolytes (hence the measuring of water levels), and I will need to be able to switch the electrolytic process on and off (hence the need for a programmable switch).

My reason for doing this is "just because".

Quote
Well, all this kind of depends on whether you're doing this on an industrial scale (with industrial explosive atmosphere considerations), or at the kitchen sink with some old coffee jars.

I am not doing this on an industrial scale.

Quote
This depends upon the voltage and current of the electrolysis process. Or are you asking about how to do the actual electrolysis?

I am clearly not asking how to do the actual electrolysis, all I want to do is turn the process on and off via the Arduino. Voltage is 7.2 and current should be 500 mA (though I am open to the current varying to another up to 3A).

Quote
Same as above: what did you have in mind? My guess is that it's low-voltage high-current DC in which case a MOSFET would work, or a relay.

Peltier draws 3A from 10V of DC.

Quote
What kind of weight difference are you looking for? A change of a few grams, hundreds of grams?

A few grams.

Quote
This looks like a High School project and you want us to do your home work. That's fair enough -- some people love to help with those projects.

It is not a High School project.

Quote
PS: Do you know how to be safe with hydrogen? Is this a supervised project? You do know about explosives -- right?

I know how to be safe with hydrogen.

Quote
You do realize that you will supply more energy than you retrieve from the process -- right?

Yes.
53  Using Arduino / Project Guidance / Arduino to control switches on: March 27, 2011, 10:30:31 am
I want to use Arduino to control the production of hydrogen/oxygen via electrolysis, and the condensation of water from a peltier cooler.
Presumably I'd need 4 things:
1. A switch to initiate the electrolysis which I could control from Arduino
2. A switch to initiate the peltier which I could control from Arduino
3. The ability to measure how heavy the peltier gets (to know how much condensation has formed on it)
4. The ability to measure the water in collection vessel so I know when the electrolysis should stop (when the water gets to a certain level)

Now I have found this for 4, but other 3 I am stuck on, and would like some assistance as to what hardware I should get to accomplish this.
54  Using Arduino / Motors, Mechanics, and Power / Re: Arduino + Servo Help on: March 27, 2011, 10:07:07 am
I would also like to add upon using the read() function of the Servo library, it just constantly reports 1 (even if i manually change the position by hand)
55  Using Arduino / Motors, Mechanics, and Power / Re: Arduino + Servo Help on: March 26, 2011, 06:57:49 pm
I hooked it up to a lab power supply and set it to roughly 4.8V (hard to tell as it is an analog interface). Still no go but I haven't tied the grounds together, what do you mean by this?
56  Using Arduino / Motors, Mechanics, and Power / Arduino + Servo Help on: March 26, 2011, 07:52:53 am
I'm trying to set up Arduino to use the Sweep code on a servo I have.
I am using an Arduino Uno and this servo: http://toysdownunder.com/light-weight-servo-3-7g.html

I plugged the gnd in, the signal cable to digital pin 9 and the power cable to 5V. When I plugged it into 5V however the Arduino would turn off, take it out and it would start back up again. So I plugged the power cable into 3.3V and the Arduino would stay.

Anyway this setup isn't working for me, as the servo isn't working. Is this because the servo I am using is busted from me trying to use it on 5V when it is recommended for 4.8V? Or perhaps its because the Arduino is feeding off the power from the USB? Any troubleshooting advice would be great.
57  Using Arduino / Project Guidance / Re: Shields and Breadboards on: February 02, 2011, 10:40:12 pm
Well the shields that I can see that conflict are the
WiShield 2.0: http://shieldlist.org/asynclabs/wishield-v2
WeatherShield1: http://shieldlist.org/ethermania/weathershield1

They both use D7 and D2 pins, now I could probably reroute the pins and change the software for interacting with them, but this is just the first problem, I also want to add a XBee shield and a motor shield (as well as many other sensors), so can I somehow extend the number of pins I can use on the Arduino?
58  Using Arduino / Project Guidance / Shields and Breadboards on: February 02, 2011, 08:56:48 am
So I have quite a few shields sitting around right now, and I would like to use at least 4 of them in my latest project, however I know that the shields make use of the same pins. Is it possible to get these shields running by interfacing them to a bread board or am I physically limited by the amount of pins connected to the Uno?
59  Using Arduino / Project Guidance / Re: Controlled water leaks on: February 02, 2011, 04:45:48 am
Thanks for the posts, I was originally going to use a water flow meter (with a rotary sensor in it) but I think the tape will be much better at measuring water in the bladder. Quick question though, how quickly will the tape respond to changes in the water level?

Or alternatively should I use this:
http://www.seeedstudio.com/depot/g12-water-flow-sensor-p-635.html

Could this be used as both a valve and a water flow sensor, and is it sensitive enough to detect changes in the water flow accurate to a ml, also would inertia effect it?

As for a valve, I have been reading around and I wouldn't mind trying a pinch valve as a cheap and not power hungry alternative, but how effective are these kind of valves at not letting drips through (because this will really be on a drip by drip basis)? If the pinch valve is the way to go, can anyone recommend a clamper?
60  Using Arduino / Project Guidance / Controlled water leaks on: February 01, 2011, 09:17:25 am
I am looking to build an Arduino project that contains a bladder of water, and then controls the valve that lets water out of that bladder until it has reached a certain capacity (and does so at a low cost to power). Does anyone know if this is feasible?
Pages: 1 2 3 [4] 5