Author Topic: EE/CE: improve electronic gadgets and spend less!  (Read 3323 times)

gimp

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EE/CE: improve electronic gadgets and spend less!
« on: August 23, 2013, 03:03:24 PM »
Hiya folks,

I was looking for an intervalometer for my camera. The cheapest decent model is $35 on amazon, and is kind of crummy.

The remote control for my camera is insanely simple: a 2.5mm jack has three connections - base, middle, and tip - and one simply shorts middle to base to focus, and tip to base to take a picture. For those of you who don't do electric stuff, here's how easy that is: If you plug the wire into the camera, and lick the other end of the wire, it will take a picture because your tongue will complete the circuit. (Tiny voltage and almost zero current means you won't feel it! But disclaimer, don't do it because you read it here.)

For $35, I am able to:

1. Most importantly: replicate the functions of the $35 device; no point creating something worse
2. Order circuit boards - $15 from seeedstudio fusion for 10x boards (super cheap!)
3. Add a fancier microcontroller than required ($3) so I can program new modes that don't exist to suit my needs over the years
4. Make a user interface allowing more options
5. Add USB charging
6. Add USB communication with any computer device (including phones, little boards like the ras pi, etc), as well as serial communication (for other microcontrollers)
7. Add the ability to let other sources control the camera through the board - for example, my phone, or a wireless controller - and let the boards be daisy-chained to control multiple cameras at once
8. Practice circuit design and board layout!

There are a lot of consumer devices that are just disgustingly simple. Some other examples include battery chargers ($1 circuit board, $0.50 - $2 battery holder, $1 usb connection, $1 charger chip with appropriate resistors, capacitors, indicator LED, etc), power adapters (12V car output to 5V USB; 9V battery to 5V USB... anything to USB is easy; though I might pay the $5 for a 120VAC to 5V USB to avoid the headache), and so on. You can often drastically improve the product; I'd rather have one common power supply board instead of eight different converters. It's a lot of fun to build these things, often for half the cost, and exercise your head-meat muscles! Of course, it has to be fun, otherwise you're spending 10 hours to save $10 and add some functions.

Sometimes you find a consumer device that actually makes sense to build from scratch even if it's not your idea of a relaxing after-work activity. For example, I'm looking at making a signal generator for some specific stuff; this would cost $25 instead of $300 or more. The best part about doing this is that you might get a business opportunity out of it.

ncornilsen

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #1 on: August 24, 2013, 08:47:58 AM »
I'm no EE (only a ME) but that Seeed source thing is awesome!  I've got a CNC milling machine I did a control retrofit on, and made a bunch of optically isolated inputs using those radioshack perfed boards... now that I found out about that, time to clean up that rat's nest!

VasyaPupkin

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #2 on: August 24, 2013, 12:36:01 PM »
Another place for budget minded hackers is www.oshpark.com
It's a US based service, batching many separate board orders into a single panel. It costs $5 for square inch, and you get three copies shipped free in about 12 days on average.  I use him a lot, you get fancy purple boards with gold finish, and for a small 1"x2" board you pay $10 for three copies. A bit more expensive than seed studio, but it stays in the country and quality is much better

gimp

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #3 on: August 24, 2013, 12:49:38 PM »
Another place for budget minded hackers is www.oshpark.com
It's a US based service, batching many separate board orders into a single panel. It costs $5 for square inch, and you get three copies shipped free in about 12 days on average.  I use him a lot, you get fancy purple boards with gold finish, and for a small 1"x2" board you pay $10 for three copies. A bit more expensive than seed studio, but it stays in the country and quality is much better


Awesome! Unfortunately my boards are too big to make this work (the battery is a one square inch alone) for the money, but if I ever make really small boards, this has moved up to my #1 choice. And I'm making something that small in the next couple weeks, so, awesome. Thanks!

I'm no EE (only a ME) but that Seeed source thing is awesome!  I've got a CNC milling machine I did a control retrofit on, and made a bunch of optically isolated inputs using those radioshack perfed boards... now that I found out about that, time to clean up that rat's nest!

Good idea! And VasyaPupkin has another source if your boards are around a square inch, which is even cheaper. I assume you know how to use eagle, or kicad, or several other free circuit design + board layout + gerber generation tools?

Jamesqf

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #4 on: August 25, 2013, 02:40:50 PM »
I was looking for an intervalometer for my camera. The cheapest decent model is $35 on amazon, and is kind of crummy.

Depending on your camera, you might be able to do even cheaper than that.  If it's a Canon digital, check out the CHDK software, which allows you to do things like set up infintely programmable intervalometers: http://chdk.wikia.com/wiki/UBASIC/Scripts:_Ultra_Intervalometer  Don't know about other camera brands, but I would think that any modern digital with a large user community would have developed something similar.

Ductyl

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #5 on: August 29, 2013, 02:35:56 PM »
I agree with the spirit of this post entirely, but for anyone looking for a ready-made cheap intervalometer, I picked one of the cheap ~$10 ones up from eBay a couple years back, and it works perfectly fine for my needs. The only feature it doesn't have that I wish it did is an on/off switch! But I just flip one of the batteries when I want to store it for a while.

gimp

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Re: EE/CE: improve electronic gadgets and spend less!
« Reply #6 on: October 01, 2013, 11:17:49 AM »
Just wanted to report back!

1. For about $50, I built a $200 camera controller. It's awesome, it does anything I want, especially since I can reprogram it to add more modes or smarter features. Comparable controllers are $200 and not modifyable by me.

2. I took the design and cut it down to remove all the fancy control logic, leaving just the basics. It costs me $8 shipped to make just one, including materials like flux and solder, but excluding other tools such as the soldering iron. This is cheaper than the cheapest ones on ebay and amazon. Of course it's a labor of love, since nobody spends hours on design and parts selection to save $2, but it shows that I can do better than established companies, while learning valuable skills. (If you're wondering where the major cost difference is, it's that they have a nice plastic case and I have an exposed PCB.) Once I properly validate my design (as opposed to just saying it works), it gets open-sourced and uploaded on my website.