Show Posts
Pages: [1] 2 3 ... 490
1  Using Arduino / Project Guidance / Re: Which Arduino should I buy for my design idea ? on: April 16, 2014, 09:46:08 am
This is a pretty big project. Yes, get an arduino MEGA 2560 R3 for this job. For water level sensing, you can also mount a sonic ranger on the lid of your tank cover to let the sonic ranger face down. Water will reflect is sonic pulse and you get distance from water surface to the tank lid. If someone removes the lid then the reading will be like 6 meters. If distance is an issue (15 m), do it wirelessly then. I don't know your budget, if you have enough money, have a tank unit with arduino and xbee radio for wireless communication with an apartment unit with another arduino and xbee radio. This way the wires are gone. You do need a solar charger and battery for the tank unit, if there is no power outlet there.

I use a lot of xbee products to build data loggers. They are nice.
2  Using Arduino / Project Guidance / Re: Video-out to a 640x480 LCD display on: April 16, 2014, 09:38:33 am
Your project is pivoted upon the assumption that the screen works and takes some RGB or analog video signals. Can you confirm this first?
3  Community / Website and Forum / Re: IE token problem forum not loading on: April 16, 2014, 09:34:37 am
I always do the chopping to only forum address. It doesn't work. At least I know it's not my win 8 computer or IE.
4  Community / Bar Sport / Re: The next big thing in battery technology on: April 15, 2014, 03:05:57 pm
I heard that this works as a capacitor charging up in 30 seconds and then the capacitor charges the actual battery. What's more interesting was one of the videos that showed up after I played this one, a guy replaced his car battery with super caps. "Boostcap".
5  Community / Bar Sport / Re: Adafruit's new website on: April 15, 2014, 02:48:36 pm
They have really good stock pictures. On a phone the mobile site is loaded, which is not too slow. The navigation improved somewhat from my viewpoint. With the navigation column removed, more space is dedicated to content. It looks boxy, like win 8. That's a neutral comment. I took about a couple hours to go through all their categories and picked the things I need for a grant-funded project and saved all to wish list. It's good. Just wish it loads faster, especially the wish list, when I have a few dozen parts in it.
6  Using Arduino / Project Guidance / Re: Data storage on SD card - file organisation, library search. on: April 15, 2014, 11:14:58 am
A simple solution might be to store your data as fixed length strings and then you could retrieve the Nth string by skipping the appropriate number of bytes.

...R

I second that (that is, I support this solution).

Use a standard C function called sprint() to format the numbers to be stored and use sscanf() to read them back.

Tutorials on my blog:
http://liudr.wordpress.com/2012/01/16/sprintf/
http://liudr.wordpress.com/2012/01/30/sscanf/
7  Development / Other Software Development / Re: Save data to file on: April 15, 2014, 10:49:24 am
Hey Emix,

I lost track of this post. Would you be interested in competing at the AAPT apparatus competition this summer? Impress construction! I would like to know more about it!

http://www.aapt.org/Programs/contests/apparatus.cfm
8  Community / Bar Sport / Re: Adafruit's new website on: April 15, 2014, 08:25:13 am
The new one has a drop down menu instead of a column of navigation links on the left. It works fine for me. Mobile version also has hi res graphics, loads fine.
9  Using Arduino / Project Guidance / Re: Arduino for this? Or something else? on: April 15, 2014, 08:21:27 am
Ok, I made the wrong assumption. Sorry about it. It does need an arduino. A couple of options here, build a stand alone atmega328 or purchase a cheap arduino nano.
10  Using Arduino / Project Guidance / Re: how to drive robot straight... on: April 14, 2014, 11:44:55 pm
Even with encoders, I bet the minute difference in friction when the OP starts motor at full speed may just turn the robot a tiny bit, which is enough to make it travel in a kind-of-straight line but off from forward.
11  Community / Bar Sport / Re: Adafruit's new website on: April 14, 2014, 11:43:06 pm
I'm using a "fast internet" service of unknown Mb/s and using latest core i 5 computer. It's probably pictures (too high resolution).
12  Community / Bar Sport / Re: Has Atmel significantly raised 8-bit MCU prices recently or is this Digikey? on: April 14, 2014, 11:41:46 pm
Dipmicro in at niagra falls so they ship to US from within US and if it's Canadian order, they just ship in Canada. If you purchase more than $15, use ILOVECANADA for free shipping. Has to be less than 13 oz in total otherwise first class mail won't ship.

Many Chinese ebay stores ship from Hongkong. It's a free port, so shipping must be a lot cheaper. The US international rates are super high. I used to get lots of international orders smiley-sad
13  Using Arduino / Project Guidance / Re: Arduino for this? Or something else? on: April 14, 2014, 02:34:07 pm
This + arduino nano clone from ebay costs less than a raspberry pi.
14  Community / Bar Sport / Adafruit's new website on: April 14, 2014, 02:33:13 pm
It's looking nice but so slow. It takes forever to add an item to wish list. What are your experiences with this new site?
15  Community / Bar Sport / Re: Has Atmel significantly raised 8-bit MCU prices recently or is this Digikey? on: April 14, 2014, 02:32:05 pm
I know, mouser has run out. I got a hundred before they ran out, at $2.8 each. I will be waiting and placing an order when they are back in stock. Good call, placed it in my scheduler. Forgot that myself and no taxes!

Yeah, the nice labeled ones from dipmicro.com Just not enough to go around. Bootloading takes 9 seconds with Optiloader.
Pages: [1] 2 3 ... 490