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16  Forum 2005-2010 (read only) / Interfacing / Re: IR on: November 11, 2007, 01:35:03 pm
Hi

You need to wire your receiver like this:

http://www.hippy.freeserve.co.uk/picaxeir.htm

Check the third paragraph 'The IR Receiving Circuit'.

Have fun!
17  Forum 2005-2010 (read only) / Interfacing / Re: H Bridge IC on: November 10, 2007, 03:57:56 pm
The 293 is a perfect choice. It's cheap, readily available, easy to use and pretty robust. I'm just soldering one in place right this moment. ..!

If I can help in any way just yell.

Charlie
18  Forum 2005-2010 (read only) / Interfacing / S*ny SIRCS decoder library - IR Control on: November 10, 2007, 04:07:51 pm
Hi!

I've just posted my first library on the playground. If you want to get into receiving commands from a sony-compatible remote handset, this might be the thing to get you on your way.

Comments invited!

http://www.arduino.cc/playground/Main/IRLib

Charlie
19  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: March 25, 2009, 06:10:24 am
Thanks smiley

This procedure would likely be the same with whichever library you use. The SPI protocol for writing to the card goes like this:

1. Send 'write sector command' - 0x58 a b c d 0x00
2. Await command acceptance - ie you receive 0x00
3. Send data token - 0xFE
4. Send 512 bytes
5. Send dummy checksum - 0x00 0x00
6. Await 'done' status code - ie you receive 0x00

Mostly these 6 steps are all wrapped up in a function. What I suggest is that 1-3 are split out into one function, 4 in another, and 5-6 in yet another.

StartWrite() - does 1-3
WriteByte - actually would be the existing 'xfer byte' routine
EndWrite() - does 5 & 6


Start the write with steps 1,2,3.

Then write bytes at a time (step 4) until you've sent 512 of the blighters.

Do 5 & 6. If you want to continue, start again at the next sector with steps 1-3.

Let me know how you get on!
20  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: March 24, 2009, 02:04:03 pm
I did find that I'm not setting high speed mode  :-[

This might improve matters.

Another thing you might consider is setting up a 'double buffer' system, where you're reading values into one buffer under interrupt control whilst writing the other. You can tune the sampling rate so that you get a consistent period.

Another thing to do might be to break the 'write sector' function so that you can write bytes at a time... You'd have to re-send a command every 512 bytes or so, but that shouldn't take long - there's a latency of about 12 bytes as the write is finished up, then the next sector is primed.

Sorry if that all sounds quite complicated - but it has to be. You don't get something for nothing on a microcontroller  smiley-razz

21  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: March 24, 2009, 01:45:39 am
512 bytes is the sector size of the device.

Why do you want to write smaller blocks?
22  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: March 22, 2009, 12:09:59 pm
Read to the end or hop over here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1235125412/
 smiley
23  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 20, 2009, 05:25:46 am
I've summarised all of this good stuff in a new thread:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1235125412

I'm sure I've missed something smiley-razz
24  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 19, 2009, 05:45:35 am
The voltage requirements at the MMC card inputs (MOSI, CLK, /SS) are defined in the MMC card product manual:

VDD in this case must be between 2.7 and 3.6v.

Input HIGH voltage:
min:  0.625 * VDD
max:  VDD + 0.3

Input LOW voltage:
min:  VSS - 0.3
max:  0.25 * VDD

As long as the voltage tapped off the divider falls within this range, all should be well.

The document to read is here:
http://www.sandisk.com/Assets/File/OEM/Manuals/ProdManRS-MMCv1.3.pdf

25  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 17, 2009, 04:09:04 pm
@NachtWind -

Quote
If i look at your pics, especially those close-ups of your shield makes me realise that i need more than a few pins and cables to connect the card to the arduino..

The board there 'has a lot more than the requisite 6 resistors and a regulator' smiley

It also has a monostable multivibrator to drive an LED which flashes when there's a positive transition on the clock line.  That accounts for about 6/7 components  smiley-grin
26  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 17, 2009, 03:58:05 pm
Hi all.

I'm back from a short break - I'm glad to see things happening.

The wiring should be the same for the ladyada code - the arduino's hardware SPI support works on a certain set of pins only. I tried my code out on a ladyada GPS board at dorkbot London a few weekends ago and it worked without modification.

As for using the ladyada code 'to get around the limitations of uFat' - well we're going full circle smiley-wink uFat is my way of getting around the limitations of having very little RAM and flash left after using the full FAT library..!

If your sketch is quite small and you can use the more fully featured library then I would suggest doing so as it makes your life really easy! uFat was designed for situations when this isn't quite the case smiley I've traded simplicity for RAM. A full sketch of uFat, MMC & deviceprint will use under 5k. You have to make compromises - this is a classic trade-off!

The DevicePrint code will work with anyone's library. You do need the arduino IDE version 0012/0013 though.

@JB - you're spot on. The file needs to be stuffed beforehand. And contiguous! Else strange results are going to happen  smiley-razz



27  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 15, 2009, 05:36:36 am
Hi

I always reach for this diagram:
http://www.interfacebus.com/Multi_Media_Card_Pinout_MMC.html

SI on the diagram  =  arduino MOSI
SO on the diagram  =  arduino MISO

I always ground pin6 even though it says NoConnect.

So wire it like so:

sdCARD    ARDuino
1         10
2         11
3         gnd
4         +3v3
5         13
6         gnd
7         12


It looks like a great harness you've got there but I suspect that the little legs aren't making a good contact with the socket. Try making a plug-in board - you'll use it over and over.

When it comes time to attach it to protoboard I usually bend the little pins down a bit and use them to locate to the card solidly. I tack them, then solder the tabs at the sides to lock the holder in place. As you might expect really.

Check out some of the photos on a few of the posts on my blog, especially http://arduinonut.blogspot.com/2008/09/lash-up.html and http://arduinonut.blogspot.com/2008/09/programmer-redux.html

Test your wiring by writing a sketch to make all of the signal lines high, measure them (without a card in place!!) and then make them low, measure again. Test for shorts.  

I hope there's something here that helps.

Charlie
28  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 13, 2009, 09:49:11 am
As it stands the libraries don't compile under 11 - the Print functionality hasn't been abstracted from the serial library in this version.

You'll need to upgrade to version 0013. http://arduino.cc/en/Main/Software.

It also looks from this error that the mmc, microfat and deviceprint folders haven't been copied to the folder

arduino-00XY\hardware\libraries

which is where they should live.

I hope the upgrade won't cause you too many problems, but there are issues with some sketches - the libraries changed significantly during the 11-12 transition. You can keep both versions side-by-side though, so if you have a problem sketch just compile it under 0011. For all new work, start out in the 0013 IDE.

If you do need to port code then the rule seems to be - if it's an .h file then add

#include <WConstants.h>

and if it's a cpp file, add

#include <WProgram.h>

Good luck. If you need any help just yell.

C

29  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 12, 2009, 09:38:51 am
A few posts ago bobemoe posted code to use the Arduino library print routines to output strings to an mmc card. I've spoken with him and used his code as a basis for DevicePrint. It has been modified to fit my usual criteria - small & tight with few (if any) dependencies.

Get it herehttp://arduinonut.blogspot.com/2009/02/libraries.html along with some of my usual written drivel about whatever and stuff.

Commentary and questioning welcomed as usual. Enjoy.

C
30  Forum 2005-2010 (read only) / Exhibition / Re: SD card read/write with Arduino on: February 12, 2009, 09:33:23 am
Hi

Kind-of, and no. The library is intended for tight memory situations where you are willing to accept limitations in usage. uFat allows you to find the starting sector and length of a file on a fat12 or fat16 formatted device.

You can then read data from and write data to those sectors. It doesn't understand the filing system more than it needs to, which in this case is only reading the boot sector, partition table and directory.

In most cases this has been quite enough for me!

Charlie

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