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1  Using Arduino / Sensors / Re: Temperature and Pressure sensor with display and wireless to be on: January 16, 2013, 01:43:36 am
for the direction.  I don't think , but I that website led me to this project I think is going to .
I am very new to this Arduino stuff and I would like for my project go well. 

I have used this OK but it iss only for LAN, not a path to the internet

2  Using Arduino / Interfacing w/ Software on the Computer / Cosm graph problem on: January 04, 2013, 07:57:50 pm
This is a bit off-topic but I'm anxious for some quick feedback and the matter might not be exclusive to cosm.

I had cosm running fine for several days

Suddenly, I could no longer see the graph but the data was still being uploaded OK as I could see it in the orange boxes. This led me to believe that the problem was at the cosm end.

I now find that I can see the graph on the laptop and the tablet.  I therefore conclude that the problem is the Firefox installation on the desktop. I can't see the graphs on the desktop using IE8 either, but I'm prepared to put that down to another issue as I don't normally use IE8 for anything.   

The laptop uses Firefox, the tablet has its own Android stuff.

I suspect my problem is caused by a Firefox automatic update, and I am wondering what to look for.
3  Using Arduino / Displays / Re: Problem with LCD + Ethernet Shield on: January 04, 2013, 07:11:29 pm
The chances of your ethernet using pin 4 are more very good than maybe. It is the typical select pin. You say ethernet and LCD shield. If you have both on one, there would surely be a jumper block so that you can properly set it up. I have never seen ethernet and LCD on the same shield and therefore assume you have exactly the the same problem as I had. My LCD shield uses 8,9,4,5,6,7.

The only solution I could come up with for certain was in fact the obvious one.  Use the pototyping shield between the Ethernet and the LCD shields to re-route pin 4 elswhere.  In my case:

1. clip off male pin 4 on a proto shield

2. run a jumper thereon from 4 to 16

3. change the sketch to read LCD 8,9,16,5,6,7

You might find that you can run the jumper on the LCD  shield, and clip its pin4 instead. My shield looks like it is made to do that, but I wasn't game, and didn't need to.

4  Using Arduino / Displays / Re: Formatting the output, JHD204A LCD on: January 04, 2013, 06:46:55 pm
I have wondered the same thing.  Like having a variable in the command -  lcd.setCursor(p, 1); and converting data into strings of a fixed length.
I have found that using leading zeros, like

     if ((second) < 10)

and junk-clearing blanks like

  lcd.print("     ");

suffice so far.....
5  Using Arduino / Programming Questions / Re: Can I Use 16 x 2 LCD Code for the 20x4? on: January 04, 2013, 06:19:41 pm
....d my blue 16 x 2 LCD shield  If I buy a 20 x 4 LCD shield, will it plug and play with the same code? Will the old stuff like:

Since you ask the question, not very likely.
First up is a nomenclature problem. You say you have fried your 16x2 shield. This implies a display using four data lines, amongst others, quite often with a little keypad, using the standard library included with the IDE, which uses the command you quote - lcd.begin(16,2); .  

I have never seen a 20x4 on a shield. I have only seen bare devices that connect by flying leads. They are I2C devices, using two data lines, different pins, and a different library. The start-up command is typically - LiquidCrystal_I2C lcd(0x27,20,4); .
Further, in the unlikely event that you actually find a 20x4 on a shield and/or using the standard library, you will probably regret buying it.  Indeed, I get the impression that I2C is becoming the norm for 16x2 displays as well.

This only means that you need to be aware of what you are doing, not that you have a serious problem. I found it a lot easier to get the I2C 20x4 going than I did the 16x2, and now switch between 16x2, 20x4, and Nokia 5110 @ 12x6 with just slightly different versions of the same sketch.  The rest of the coding for any character LCD is essentially the bleeding obvious.
6  Using Arduino / Displays / Re: 16 x 4 LCD Library on: January 03, 2013, 10:22:07 pm
It appears that LiquidCrystal_I2C can be configured for 16x4.
7  Topics / Home Automation and Networked Objects / Re: Mac connection for data logging - WiFi or Bluetooth on: January 03, 2013, 07:17:40 pm
Logging to SD card is a good way to go if you don't need live connection.

And a really good idea even if you do use a live connection. Once you have the initialisation sorted, SD is the reliable backup....
8  Using Arduino / Displays / Re: SainSmart 20 x 4 LCD wanting to use I2C from Arduino Uno on: January 03, 2013, 06:39:17 pm
I didn't realise I had "wire.h" and not <wire.h>. I can only conclude it makes no difference!


I've changed it and it works the same.

Also Dafes looks the same as mine, except he is using 16x4 instead of 20x4. The backlight bit is the same.
9  Topics / Home Automation and Networked Objects / Re: Mac connection for data logging - WiFi or Bluetooth on: January 03, 2013, 06:12:41 pm
The Leonardo differs only in detail from the common or garden varieties of Arduino, and everything you suggest is doable. For reasons I don't understand, a wifi shield will cost more than the rest of your Arduino kit combined, and more than ten time as much as a bluetooth module. But I guess it can be your last choice anyway. 

SD card modules come included on ethernet and display shields. 

The files and comms are universal and the Macbook should be just as servicable as a computer. I use a cheapo JY-MCU bluetooth and a freebie terminal RealTerm for real-time datalogging. There is bound to be a Mac equivalent of RealTerm.

Even with time and date stamping, a 2G card would hold about a year of data, so you might not need to consider any communication.

10  Using Arduino / Displays / Re: SainSmart 20 x 4 LCD wanting to use I2C from Arduino Uno on: January 03, 2013, 05:10:02 pm
We have the same library and the display should probably work the same. The display is disconcerting on start-up and you might think it is faulty. The light comes on and then goes goes off, then comes on fully operational.

Here is the start of a clock. Note that I don't define the backlight pin.

//Arduino 1.0+ Only
//Arduino 1.0+ Only

#include <LiquidCrystal_I2C.h>
#include "Wire.h"
#define DS1307_ADDRESS 0x68

LiquidCrystal_I2C lcd(0x27,20,4);  

void setup(){
      lcd.backlight();  //Backlight ON if under program control
  // Print a message to the LCD.
 lcd.print("Today it is");

void loop(){

11  Using Arduino / Displays / Re: Struggling with the Nokia 5110 on: January 02, 2013, 06:16:26 pm
got it to work?

Yes, thanks. I'm so pleased with it that I am using it as my standard display! I have bought a second one and built it onto a small shield. It has a blue backlight which is absolutely useless and it is better disconnected. The first has a white light, and I hope yours has too...

when I wrote
I cannot get the backlight to work. I did have it work momentarily, which was a real surprise. At the time, I had the wires that I thought should work it in my hands, not actually connected to anything. I have not been able to duplicate this trick.
I think the light must have been grounding through my hands.

I re-wrote the first three stand-alone sketches so that the setup was the same in each. I was able to improve the display a little but the quality seems to depend on what is being displayed.

I now use the same library as you and have been able to improve the text and spacing by breaking the words up and judiciously using the cursor.

Are you aware it runs on the SPI bus? It seems to be the best-kept secret of the 5110.
12  Using Arduino / Displays / Re: SainSmart 20 x 4 LCD wanting to use I2C from Arduino Uno on: January 01, 2013, 10:22:43 pm
Hey everybody! Happy New Year! My new sainsmart 20x4 LCD showed up today and all I got was the LCD? No documentation and no cable for connecting it to the arduino. Could someone tell me what type of connector I need so I can make a cable? Thanks!

Happy new year.

I use LiquidCrystal_I2C.h. You could make up a cable using standard 0.1" 4 pin females, but I just tore off four conductors from a 40-way ribbon with females already included.
13  Using Arduino / Sensors / Re: DS18B20 Incorrect Temperature on: January 01, 2013, 10:10:48 pm
Good luck, all should work out fine. I forgot to point out that the 85 is not the maximum value, it is the maximum temperatrure at the highest order of accuracy. The maximum is 125.

More particularly, 85 is the value you see when you do a power-on reset and, while I don't know the detail of you circumstance, that is probably what you are seeing and is nothing to worry about. You hardly ever see this in normal use.

The code from the Arduino Playground and PJRC results in a temperature of 85 C for all probes which when reading the datasheet from the sensors, that is the maximum value.
14  Using Arduino / Programming Questions / Re: Setting Arduino's date and time? on: January 01, 2013, 08:03:11 pm
Whenever I create a file on the SD card, through the Arduino and the WiFi shield, the date and time of the file creation is set to the standard January 1, 2000 00:00. I have found how to connect to an NTP server and read the current date and time.  But how can I set the current date and time on the Arduino for it to use in it's other operations such as file I/O?

I think the simplest approach is to do your own stamping using a DS1307 clock module. You can use it to name the file and/or include date/time in the data. In my case, the clock is used to create a new file at midnight  - 20130102,csv - and thus only the time need be recorded therein.

in preamble:
File myFile;
char filename[] = "00000000.CSV";

in Setup

the condition in the loop:
 if (hour == 0 && minute == 0 && second <2)

the subroutine:
void getFileName(){

  DateTime now =;

  filename[0] = (now.year()/1000)%10 + '0'; //To get 1st digit from year()
  filename[1] = (now.year()/100)%10 + '0'; //To get 2nd digit from year()
  filename[2] = (now.year()/10)%10 + '0'; //To get 3rd digit from year()
  filename[3] = now.year()%10 + '0'; //To get 4th digit from year()
  filename[4] = now.month()/10 + '0'; //To get 1st digit from month()
  filename[5] = now.month()%10 + '0'; //To get 2nd digit from month()
  filename[6] = + '0'; //To get 1st digit from day()
  filename[7] = + '0'; //To get 2nd digit from day()

  myFile =, FILE_WRITE);


Maybe you could get the same result with your NTP server.
15  Using Arduino / Project Guidance / Re: time clock module.. on: January 01, 2013, 07:06:07 pm
The clocks are the same, they just look different. I have the blue one just like yours. I had as seriously bad time getting any joy from it. This was partly due to my being a newbie, but far from wholly. I believe there is a swag of confusing and out-of-date junk out there - and badly written too. Since you ask the question, I assume you two are newbies. Being a newbie puts you at the disadvantage of having the latest gear, thereby having to sort the wheat from the chaff, and quite a lot of that chaff is in the Arduino playground.

About the only decent up-to-date tutorial written for the  DS1307 is here

Read the first line in the code twice, indeed they write it twice.  

You only need four wires. Most of the terminals on the blue board are duplicates and it doesn't matter which one you use.

There are two sketches, one for setting the clock and the other for running. You write the setting time in the first sketch and the start point is when you release the reset button. Needless to say, the two sketches can be merged if you wish, and it might be an interesting programming exercise involving serial read, but I haven't bothered. My module came running on Shanghai Time.
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