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16  Using Arduino / Project Guidance / Re: fast movements triggers vibration on: April 07, 2014, 01:10:52 am
Gyro senses orientation, accelerometer senses acceleration.
Yes, you should have a threshold to trigger the vibration.
17  Using Arduino / Project Guidance / Re: Powered (automatic) rocker on: April 01, 2014, 12:15:50 pm
The frequency should be the natural frequency of the baby pendulum. Forcing any other frequency would be not only energy inefficient but, I would assume, also not comfortable.

+1 on the spring / tension cord coupling. Rigid connection would most likely result in damage to the motor and/or coupling. You would want to provide some breathing room for the moments when you put the baby in and out or when you want to take over and switch to "manual control".
18  Using Arduino / Project Guidance / Re: Powered (automatic) rocker on: April 01, 2014, 12:35:12 am
Following up on Peter's concern, this comes to mind.
19  Using Arduino / Project Guidance / Re: Multiple DSLR Triggers on: March 21, 2014, 02:10:50 pm
The really high speed shots are done by putting the camera in a dark room, pre-focus, and shoot for a long period of time, and then you engage the flash at the precise time you want (for example, n microseconds after a sound triggers for doing the popping balloon, breaking glass type shots).  Typically, you need to do it many, many times to get the timing just correct.
The really, really high speed photography is done with air gap flashes.
For the really, really, really, high speed photography there is this thing.

But back to the subject.
Synchronizing the triggering of multiple SLR cameras (or any camera with a mechanical shutter) could be affected by slightly different mechanisms in each individual camera, even if they are the same model.
20  Using Arduino / Project Guidance / Re: Multiple DSLR Triggers on: March 21, 2014, 12:59:12 am
Not if you use port manipulation.
But even without it, you can use one IO pin to control multiple optocouplers in connected parallel, like I said previously.
21  Using Arduino / General Electronics / Re: I hate surface mount soldering, (shopping question) on: March 20, 2014, 12:56:32 pm
Well, I did give you a fair warning.
smiley

But, back to serious discussion.
Why don't you pick up some breakout boards with the pitch you will need and take some random (cheapest) SMD chips of that size and practice. It doesn't matter if you burn them or if the soldering is botchy. You will certainly learn something and it might just as well be how to solder those little buggers.
22  Using Arduino / General Electronics / Re: I hate surface mount soldering, (shopping question) on: March 19, 2014, 11:34:48 am
ZIF sockets? However, that approach could get quite pricey if you need more than few chips.
23  Using Arduino / Programming Questions / Re: How does programming language relate to binary code? on: March 17, 2014, 11:43:11 am
Here's some info on compilers, assembly and machine code.
24  Using Arduino / Programming Questions / Re: complicated if statements on: March 17, 2014, 11:39:41 am
Not only that you can use brackets, you absolutely should use them in such cases, even where no brackets would work just as well.
You will avoid some hard to track bugs in similar situations where you have to use them but forgot.
25  Using Arduino / Project Guidance / Re: Multiple DSLR Triggers on: March 17, 2014, 01:02:43 am
Yes, exactly.
Here is one of many tutorials on the subject:
http://www.martyncurrey.com/?p=34
26  Using Arduino / Programming Questions / Re: Delay quicker then 1 milli on: March 16, 2014, 03:54:53 pm
I swear I knew there was something fishy, but just couldn't put my finger on it.
27  Using Arduino / Project Guidance / Re: Best wireless connection on: March 16, 2014, 03:40:39 pm
Infra red?
28  Using Arduino / Programming Questions / Re: Delay quicker then 1 milli on: March 16, 2014, 02:37:13 pm
delayMicroseconds(46440);

[/nitpicking]
29  Using Arduino / Project Guidance / Re: Multiple DSLR Triggers on: March 16, 2014, 02:26:04 pm
You could use one pin to control multiple optocouplers in parallel, each for one camera.
30  Using Arduino / Project Guidance / Re: Prioritizing power output to electrical devices on: March 14, 2014, 11:32:34 am
Robin, please do throw as much cold water as you feel is necessary. I'm not going to get offended if someone points out flaws in my ideas. On the contrary, I'm usually happy to be proven wrong, since that is how learning works.

You do bring up a good point about the devices potentially not liking being completely shut down and questioning what happens when they get the power back.
However (assuming they don't mind being cut off and that they don't do some extra work once the power is reapplied), I believe that the probability of more than one device deciding to turn on at the same time (or close enough for the Arduino to not be able to recognize it in time and shut down the second one) is low enough to consider this approach. After all we are talking about fractions of seconds. I wasn't able to find a proper datasheet for that specific sensor I linked, but some others I was able to find have response times of 100 to 500 ms.
I assumed the appliances described worked based on thermostat.
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