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1  Products / Arduino Due / Re: Gameduino + Arduino Due? on: January 21, 2013, 08:24:33 pm
Gameduino is 3.3V and uses SPI, so shouldn't be a problem except the SPI is on different pins. (Haven't received my Gameduino yet so can't confirm.)  smiley-roll-blue
2  Using Arduino / Microcontrollers / Re: Arduino ethernet sheild wiznet chip become too hot! on: October 11, 2012, 08:51:00 pm
Three months later... and two of the four Ethernet shields (with POE) have died. I don't know if it's due to the high temperature and humidity, or if it's because ants got into the POE switch.  smiley-cry
3  Using Arduino / Microcontrollers / Re: Using Arduino sketches with Ti Launchpad MSP430 on: August 20, 2012, 11:16:56 pm
Thanks for the update. Last time I looked this project appeared to be OS X only. Trying it out (on Windows) now...
4  Using Arduino / Microcontrollers / Re: Arduino ethernet sheild wiznet chip become too hot! on: July 03, 2012, 06:55:04 am
I have four Ethernet shields (with POE) that are used outdoors but not in direct sunlight. I would guess the temperature at noon is roughly 35C (95F) or more. The plastic enclosure gets warm to the touch but they seem to be running fine so far.  smiley-roll-sweat
5  Using Arduino / Microcontrollers / Re: What is happening to the ARM based Arduino on: June 29, 2012, 09:13:43 pm
Engadget has a review and bigger pics of the ADK 2012.

The ADK site has downloads of the IDE now, but at the moment the link for the Windows version points to the OS X version. (Edit: the link is fixed.)
6  Using Arduino / Networking, Protocols, and Devices / MAC address sticker? on: June 02, 2012, 04:15:30 am
I got a bunch of Ethernet Shields R3 (with POE) today and they don't have a MAC address sticker either in the box or affixed to the board itself unlike the website description and photos of the shields that I've seen on the net. Do current shields not come with the sticker any more? (I've never bought an official Ethernet Shield.)

I know I'm supposed to program in my own MAC address any way, but it would have been nice to not have to come up with a random one and have to keep track of the random numbers.
7  Using Arduino / Storage / Re: FAT file name restrictions? on: May 11, 2012, 04:18:49 am
Forgive my ignorance as I'm still new to working with these file systems (and don't have a way to test until later this evening) but what would displayed if a long file name were to be read by the SD lib? Does it just truncate the name at 8 characters of is it illegible?

You can only open a long filename file if you use the short filename equivalent. Use DIR /X in a Command Prompt to find out what it is. e.g. fur_elise.mp3 would be something like FUR_EL~1.MP3.

8  Using Arduino / Programming Questions / Re: String to int on: May 02, 2012, 02:47:49 am
Maybe because int only goes up to 32767. Try using a long variable and the corresponding atol function.
9  Using Arduino / Project Guidance / Re: Serve graphics with Eithernet Uno? on: April 22, 2012, 08:39:27 pm
You might be sending too fast and overflowing the buffer. Try putting in a delay inside the client write loop.
10  Topics / Science and Measurement / Re: RTC not keeping accurate time & forgetting time on: April 19, 2012, 11:11:46 pm
I have an RTC module here that's always slow by exactly 30 minutes when the battery is low, no matter what time I set it to. So I would say check the battery too.
11  Using Arduino / Microcontrollers / Re: TI MSP430 LaunchPad experiences on: April 15, 2012, 05:39:13 am
I ordered a LaunchPad directly from a few weeks ago too. The website says additional units are available every 2 weeks, and my order confirmation said 1.5 months of wait time, but I got it in 3 days. Fedex directly to my door in the other side of the world from, and it was the new version.
12  Using Arduino / Programming Questions / Re: String compound operator question on: March 17, 2012, 11:58:59 am
    dataString += String(sensor);
There is no need to create a temporary String to wrap the int before concatenating it. Doing so consumes more resources that necessary.

Okay, I guess the examples aren't perfect. Will try to reduce resource usage in my own programs.

Thanks again for your help.
13  Using Arduino / Programming Questions / Re: String compound operator question on: March 17, 2012, 10:27:52 am
Sorry, this is the sketch in question.

  SD card datalogger
 This example shows how to log data from three analog sensors
 to an SD card using the SD library.
 The circuit:
 * analog sensors on analog ins 0, 1, and 2
 * SD card attached to SPI bus as follows:
 ** MOSI - pin 11
 ** MISO - pin 12
 ** CLK - pin 13
 ** CS - pin 4
 created  24 Nov 2010
 updated 2 Dec 2010
 by Tom Igoe
 This example code is in the public domain.

#include <SD.h>

// On the Ethernet Shield, CS is pin 4. Note that even if it's not
// used as the CS pin, the hardware CS pin (10 on most Arduino boards,
// 53 on the Mega) must be left as an output or the SD library
// functions will not work.
const int chipSelect = 4;

void setup()
  Serial.print("Initializing SD card...");
  // make sure that the default chip select pin is set to
  // output, even if you don't use it:
  pinMode(53, OUTPUT);
  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
  Serial.println("card initialized.");

void loop()
  // make a string for assembling the data to log:
  String dataString = "";

  // read three sensors and append to the string:
  for (int analogPin = 0; analogPin < 3; analogPin++) {
    int sensor = analogRead(analogPin);
    dataString += String(sensor);
    if (analogPin < 2) {
      dataString += ",";

  // open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  File dataFile ="datalog.txt", FILE_WRITE);

  // if the file is available, write to it:
  if (dataFile) {
    // print to the serial port too:
  // if the file isn't open, pop up an error:
  else {
    Serial.println("error opening datalog.txt");
14  Using Arduino / Programming Questions / Re: String compound operator question on: March 17, 2012, 08:38:54 am
Do compound operators not work with String objects?
They do. The String class is a resource hog, though. I'd guess that you are right at the limit of not having enough memory.

Thanks for replying. Well, I realize the String class is a resource hog, but I'm curious why it doesn't work in this case. Surely the Mega has enough memory for a simple string in an example sketch? Besides, changing the compound operator to the regular concat operator works.
15  Using Arduino / Programming Questions / String compound operator question on: March 17, 2012, 03:03:46 am
I'm learning to use SD for data logging, so I'm looking at the Datalogger sketch from the built-in examples. I'm using a (clone) Ethernet shield with microSD socket on a Mega (clone). The sketch is modified to work with the Mega by changing pin 10 to 53, and I'm using Arduino 1.0. The sketch is also at

The problem is that the sketch seems to get stuck when running, the output looks something like this:

Initializing SD card...card initialized.

Changing one line in the sketch, from:
    dataString += String(sensor);

    dataString = dataString + String(sensor);

works. What's the difference? Do compound operators not work with String objects?

Thanks.  smiley-red
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