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1  Using Arduino / Microcontrollers / Re: Alternative to 16U2 on: April 20, 2014, 08:35:55 pm
Do I have to read all the spec for the Duelmilanove to understand why you guys recommended that one ? What's special about that?

See reply #5, for my thinking.
2  Topics / Science and Measurement / Re: voltage divider for temp sensor on: April 20, 2014, 08:30:06 pm
A general rule of thumb, is to select a series resistor that gives a 50% volktage with the thermistor at the critical temperature you wish to measure: Ex, for room ambident a 10K NTC would have a 10K 1% or better resistor.

Again, for room temp, my experience suggests that using the
http://en.m.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation
Tracks to within 0.5F at room temp based on 4 separate didital thermometers.  Not bad.

Be aware of the self-heating aspect of thermistors!  This can break the rule of thumb easily!


Ray
3  Topics / Science and Measurement / Re: watermeter with GSM shield on: April 20, 2014, 08:21:59 pm
If you plan on more than 1 unit, a building or commercial venture, do yourself a favor and investigate "Internet of Things"... The future us all about storing that data in the cloud.  Some sites have free hosting and tools for analytics.

Forget about MAC, envision URL.

http://iotday.org
4  Topics / Science and Measurement / Re: Data acquisition using excel or matlab on: April 20, 2014, 08:11:48 pm
The Excel part is pretty easy...
Use a Leonardo, Pro Micro, or V-USB to simulate a keyboard.
Like my project here:
http://www.hackster.io/rayburne/arduino-to-excel-using-v-usb

If the PC needs to be away, just use the same concept, pass data to SD-Card, import the <file.prn> into Excel later.

Ray
5  Using Arduino / Project Guidance / Re: void loop() 1 void loop() 2 on: April 20, 2014, 08:05:55 pm
Thanks guys,  this is working for me,  I've been able to used about 3 different timers, but is working good, thanks again

OMG!
Like will someone promote this Newbie two or three levels please!
S/He listened,
S/He read,
S/He implemented the solution.

Ulobab, you are my hero.  You are going on to great things, dude  smiley-lol

Ray
6  Using Arduino / Project Guidance / Re: UNIVERSITY PROJECT: LED, Speaker, Motor, Battery on: April 20, 2014, 07:57:51 pm
Quote
For $12 (to the US at least) this kit is a rocker. No, I have nothing to do with the vendor. It was just one of the first few kits that popped up when I looked for 'arduino starter kit.'

No...

The $9.58 is not a price... It keys the drop-down when you attempt to purchase.. Then you have to select the UNO or the Parts Kit... The parts are $43.98 + $1.99 shipping!

7  Using Arduino / Project Guidance / Re: transponder help please? on: April 20, 2014, 07:36:30 pm
RFID is still the right answer, but not the type that must "gather" RF, rectify, charge a cap, activate the uC, and transmit from the stored energy.  You are looking for a design that is battery powered (active), listens, and transmit from within a very narrow receive area where the authorizing transceivers has a narrow antenna pattern.  Every monitoring station would have an activation code which would time-date the bike passage through the zone.  As we are taking about a single packet sent from each bike, the received must be capable of distinguishing (discriminating) very narrowly spaced, but separate signals in the event of two bikes very close.

 The selection of an open frequency, the antenna design, and transceiver h/w creates a full package.  Antenna should be rather simple, an advanced HAM operator would be a handy resource.
http://www.afar.net/tutorials/antennas/

It is an interesting design problem that may or may not have a prep manufactured commercial solution.  Possibly something like the Peach Pass used on Georgia highways.
http://www.peachpass.com/latest-news-and-information/useful-links
Quote
A Peach Pass is a small, thin electronic toll collection device similar to the GA Cruise Card that adheres to a vehicle windshield OR a bumper that mounts to the front of your vehicle. The Peach Pass is connected to an account established with the State Road and Tollway Authority (SRTA) that automatically deducts the proper tolls when using the electronic toll lanes of the I-85 Express Lanes and any future toll roads in the state of Georgia. - See more at: http://www.peachpass.com/about/#sthash.NgeAp3GB.dpuf


Ray
8  Using Arduino / Project Guidance / Re: How to upload file to laptop with adafruit cc3000 and Arduino uno? on: April 20, 2014, 07:08:47 pm
Like this?
http://www.openhomeautomation.net/wireless-camera/
9  Community / Exhibition / Gallery / Re: ILI9340 SPI 2.2 inch color ASCII serial terminal on ProMicro 32U4 on: April 20, 2014, 06:53:59 pm
... I like that display.
Got a couple from eBay at $3 each. ...

Nice price, I paid a little more, free shipping, and delivery in about 10 days.  I thought the delivery was extremely fast, but they beat it by a day on my second order!

Your source still have 'em at $3?

Ray
10  Using Arduino / Microcontrollers / Re: Review of CrossRoad's through-hole 1284P Bobuino board on: April 20, 2014, 06:47:38 pm
Quote
I like the 1284P for the reasons

I like it because it is one BIG ol' chip... Makes projects look important  smiley-lol

There are plenty if cheap Chinese little boards out there that are disposable, but the Bobduini is one serious keeper!  Love it.

Ray
11  Using Arduino / Programming Questions / Re: Help me, PWM does not work on: April 20, 2014, 06:41:13 pm
Quote
I send data from the computer to the Arduino, I keep it in a variable and then sent it to pwm, but does not work, help please.

Not to be too critical, but everyone knows PWM works!  Marco_c hit on the fact that not all pins support PWM and the PWM pins vary by Arduino model of uC.
Pictures of Arduino various models with pin out:
https://www.google.com/search?q=arduino+uno+pinout+pwm&source=lnms&tbm=isch&sa=X&ei=cVxUU-6GEZHMsQT4ioCIAw&ved=0CAYQ_AUoAQ&biw=800&bih=1232

Pick your model, identify pins, use an example sketch to load a variable with a value and test... Maybe use the onboard LED.
Then read the keyboard into a variable and try again.  
When one thing works and one thing does not, investigate the difference (like keyboard characters are not integer numbers!!!)

Ray
12  Using Arduino / Programming Questions / Re: Interrupt Priority Structure on: April 20, 2014, 06:26:26 pm
Quote
Is there a switch within ide to get assembler listing  ?

Not a switch, a utility... You pass the ELF file to it...
General porocessshown here:
http://rcarduino.blogspot.com/2012/09/how-to-view-arduino-assembly.html
13  Using Arduino / Microcontrollers / Re: Review of CrossRoad's through-hole 1284P Bobuino board on: April 20, 2014, 06:02:59 pm
I have 3 of these boards and agree that this is an excellent board.  Highly recommended.

SRAM tough!

Ray
14  Using Arduino / Microcontrollers / Re: Alternative to 16U2 on: April 20, 2014, 05:56:20 pm
...Can someone tell me why he should build either of those (as opposed to a garden variety UNO) ?

My thinking is that the FTDI can be purchased as a module on breakout (or inside the USB shell on a nice long cable).  Everything else is a garden UNO and with Optiboot bootloader and the reset cap, it will work like an UNO... Just no need to deasl with 16U2 or 32U4.

Ray
15  Using Arduino / Displays / Re: Report: Inexpensive SPI based TFT Displays (PCF8833, ST7735, ILI9341) on: April 20, 2014, 05:42:12 pm
ILI934x with 32U4 Arduino Pro Micro pinouts:
http://forum.arduino.cc/index.php?topic=234601.msg1688777#msg1688777

So fast, I have 7 good ones out if 7 ordered.
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