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421  Using Arduino / Programming Questions / Re: Question about hex codes on: July 25, 2013, 10:30:06 pm
Without knowing more about the data it is not clear how you would be able to compress this large amount into 32 bits.

What are you actually trying to do?
422  Using Arduino / Displays / Re: LED board messaging on: July 24, 2013, 11:58:30 pm
I am assuming that the board is a commercial product and has a manual that you will be able to read.

In order to control the board you will need to find the communications port (socket somewhere) and a definition of the messages that you can send to the board to control it. Once you have that then you can write the software.

Otherwise you will need to reverse-engineer the communications protocol, which may be more complex than you may want to tackle at this stage.
423  Using Arduino / Storage / Re: Can anyone provide me eagle file of arduino uno with sd card shield? on: July 21, 2013, 08:23:04 pm
If you buy one of the ready made SD card units (like this one on eBay http://www.ebay.com.au/itm/Perfect-SD-Card-Module-Slot-Socket-Reader-For-Arduino-ARM-MCU-Read-And-Write-/350835892546?pt=AU_Gadgets&hash=item51af72e142), then mounting it on a Uno size protoype board is so striaghtforward that I don't think that you will find an electrical schematic is needed - you simply hard wire the same links you would use if you were putting it onto a breadboard.
424  Using Arduino / General Electronics / Re: [SOLVED] Reset for a 3.3V breakout board connected to an Uno on: July 20, 2013, 08:05:34 pm
I did some research and 2 ways stood out as being 'quick and dirty' but workable. Simplifying factors for me are that the signal (RESET) hardly changes at all and it is only one way from 5V to 3V. The easiest ways:
- Voltage divider as already previously mentioned
- Zener diode voltage clamp on the signal

Here are some references in case anyone is interested

http://jamesreubenknowles.com/level-shifting-stragety-experments-1741

http://www.daycounter.com/Circuits/Level-Translators/Level-Translators.phtml
http://webhome.csc.uvic.ca/~mcheng/466/spring.2010/handouts/references/level-translation-techniques.pdf
http://codeandlife.com/2012/04/06/level-shifting-101/
425  Using Arduino / General Electronics / Re: Reset for a 3.3V breakout board connected to an Uno on: July 20, 2013, 08:32:24 am
Here's the breakout boards https://www.sparkfun.com/products/9943

It is mounted on a UNO prototyping shield and the I/O pins are tied to start it up in MIDI mode.
426  Using Arduino / General Electronics / [SOLVED] Reset for a 3.3V breakout board connected to an Uno on: July 20, 2013, 03:29:44 am
I have breakout board for a component that is to the Uno using the serial port only. I need to reset the breakout board when the Uno is reset, but the mismatch in voltage levels (3.3V vs 5V) means that I can't connect the Uno reset signal directly to the breakout board.

Any suggestions for would be the easiest (cheapest and least components) way of doing this, given that there is just one signal whose level needs to be shifted?
427  Using Arduino / Displays / Re: Where to get 16X2 displays with pins both on top and bottom, cheap? on: July 19, 2013, 04:29:06 pm
Have you looked on eBay?
428  Using Arduino / LEDs and Multiplexing / Re: 60 Second countdown using a 2 digit Seven second display on: July 14, 2013, 04:51:05 am
I have some code on my repository (link below) for a countdown timer that may be useful for you.
429  Using Arduino / Programming Questions / Re: Question about hex codes on: July 12, 2013, 06:04:41 pm
The numbers you have listed are all 16 bit integers. The number you showed separately (0x02FD48B7) is a long value (32 bits).

Each hex digit takes 4 bits (0-F), so it is easy to work out the data types you need to store the values. Up to 2 hex digits fits in a uint8_t, up to 4 in a uint16_t and up to 8 in a uint32_t.
430  Using Arduino / Programming Questions / Re: Pointers / Data types (LCD4884) on: July 04, 2013, 09:11:50 pm
A % followed by another % character will write a single % to the stream.
431  Using Arduino / Programming Questions / Re: Pointers / Data types (LCD4884) on: July 04, 2013, 08:33:51 pm
Just to add to PaulS response, if you want to have leading zeroes for single digits, use %02d. This will keep the string exactly the same length.
432  Using Arduino / Programming Questions / Re: Calling functions from another file on: July 04, 2013, 04:59:42 pm
You can include a .h or a .cpp file, that would be clearer than the .ino.

A .cpp without objects (just functions) should also work as long as you have a separate header file with function prototypes so that the file ordering doesn't get in the way. Haven't tried this, but it should work.
433  Using Arduino / Sensors / Re: Least lines for 8 switches on: July 04, 2013, 04:52:21 pm
A parallel to serial input converter like the 74HC165 is cheap, available and uses 3 lines to interface as many of these chips as you need (they cascade). Lots of examples (code and circuits) on how these are used. Each chip takes 8 bits in parallel and squirts them out as a serial stream that you can assemble into a byte at the Arduino end. Datasheet here http://www.nxp.com/documents/data_sheet/74HC_HCT165.pdf.

The reverse comms is done using the 74HC595 chip.
434  Using Arduino / Displays / Re: Why is there a pot connected to the lcd? on: July 02, 2013, 07:21:31 am
Usually it is used to adjust the contrast for the display. Different lighting conditions can mean that you can't see the LCD so adjustment may be necessary.
435  Using Arduino / Sensors / Re: Sensor for stringed instruments on: July 02, 2013, 07:19:06 am
Electric guitar pickup?

I have also seen suggested that a piezo disc can be used to detect the vibration of the string.
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