Show Posts
Pages: 1 2 [3] 4 5 ... 145
31  Using Arduino / Project Guidance / Re: Use Arduino to record data without USB plugged in to computer? on: July 16, 2014, 02:34:43 am
Essentially right, but a 9v battery isn't a good idea, and a 9v wall art is a much better one. If you must use batteries, 6 AAs, or even 5, are a better proposition.  You will clearly need an SD of one sort or another. Note that they are usually included with Ethernet shields etc. You are also likely to need a clock.

I think taking Arduino away from the PC now is none too soon, if only because the power supply via the USB cable is marginal anyway. A wall wart is much more capable.  
32  Using Arduino / Project Guidance / Re: DS18B20 not detected on: July 16, 2014, 02:23:43 am

I just wish my waterproof ds18b20 wasn't so slow to react.

Well, what's slow?  I can grab a sensor and see the change the next time round on a one second loop. Anything faster would be stretching the friendship with the reading cycle.
33  Using Arduino / Sensors / Re: DS18B20 & IR Sensor questions(not using both together, just general Q about 'em) on: July 15, 2014, 11:16:09 pm

Regarding the DS18B20...what do you mean (I am pretty new to all this terminology) - is that something else I need to buy or is it more like adding a resistor in the path?

Edit: I found this site, and it looks like I need a SensorShield?

Ignore the site, and that, or any other, sensor shield is a bad idea unless you are certain that what you want to plug into it will plug into it, an event I have never known to happen. You are better off starting with a  $0.50 breadboard, it will be one of your better investments. Ultimately, you might make your own sensor shields, thereby by getting exactly what you want.

The DS18B20 looks a good deal at that price.   
34  Using Arduino / Displays / Re: Nokia 5110 LCD - possible broken [SOLVED] on: July 15, 2014, 10:54:53 pm
You should use a resistor for the backlight, 820 is fine. If the backlight is blue, you might find it just as readable with it disconnected.   
35  Using Arduino / Displays / Re: Keeping SainSmart 3.2 UTFT screen from cycling and sensor data display on: July 15, 2014, 09:51:16 pm
I have a  Mega 2560, SainSmart 3.2 UTFT screen, I have modified the UTFT library from ( to show only one screen of text. The screen continued to loop and clear itself, should I take the code out of the loop to keep it from clearing. Additionally I would like to display data, is there a specific command to do so with the GLCD.print options. The data would be integrated later on with additional sensor code.

You should only clear the screen when you have to. This could be in the setup, so you only do it once. By ensuring proper formatting, you should be able to do the rest by overprinting in the loop.

You will see a command for printing numbers in the Henning Karlsen manual. It looks like

myGLCD.printNumF(diff, 2, tab, 195);

where diff is the name of the variable, and is much the same as printing text.

36  Using Arduino / Project Guidance / Re: Arduino Uno with Android on: July 15, 2014, 08:33:17 pm
OK. Harking back to reply #3, this is an android problem, and I still think it is a non-starter. 

It would appear that the LEDs are indeed used as strobe illumination of a moving secret something, thereby providing rapid stop-motion - hence the need for the brief flashes. Even if you won't reveal the secret, this all sounds reasonable and your only problem is to ensure the Android is up to the job, which it probably isn't - hence my suspicion that you have been sent on a wild goose chase.

However, in the light of

to just focus on getting the Arduino and the Android synced and working together.

and grabbing the word "synched" while noting the conspicuous absence of the word "control", you might be able to tailor the job to Android's abilities. By this I mean simply using Arduino to adjust the LED flash rate to match the frame rate of Android's movie. This would mean start-time as well as frame rate.  I am assuming that you can see what's going on through Android's screen. Arduino might also be used for adjusting the LEDs brightness, but there may be no need for that. My Android has no controls for its movie camera - no surprise -  but it does have settings for the picture size and the frame-rate could vary with it.   

You will probaly want to use a frame-grabber, something like RADVideo, and you could use that to test for frame-rate by exploding a movie clip.
37  Using Arduino / Storage / Re: SD Card Module on: July 15, 2014, 07:00:14 pm
In that case, looking to check was a good idea, and using a converter isn't.

The next thing to try is ignore reply#1, delete

 pinMode(10, OUTPUT);

and use

 pinMode(53, OUTPUT);

which is standard procedure for a Mega, and clearly shown as comment in the code you already have.  Your code seems to be otherwise OK, although keeping the redundant line

   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only

can't be a good idea.

All this assumes you are using the the standard wiring for Mega

 ** MISO - 50
 ** MOSI  - 51
 ** CLK   -   52
 ** CS     -    4

or the ICSP pins, which are common to Uno and Mega. You can, of course use any pin for CS, so long as you identify it in the code.  A shield I have for a Mega uses pin 53, and this is probably common practice

const int chipSelect = 53;   

void setup(){
  pinMode(53, OUTPUT);   
  Serial.print("\nInitializing SD card...");

38  Using Arduino / Project Guidance / Re: Power between shields - VIN and 5v on: July 14, 2014, 08:41:14 pm
Something for the proto shield then? I cannot identify the regulators, they all look the same
39  Using Arduino / Project Guidance / Re: Hi. Im new here and new to electronics. Just have some noob questions. on: July 14, 2014, 07:52:40 pm
. Hundreds and hundreds of rgb and white leds. I want to be able to program all the effects myself and be able to switch from effect to effect via buttons. Thats the simplest goal for right now.

I guess the first thing to do is check out the means of powering them.

A starter kit is a fair answer if you have no idea of what you are doing and are just getting it for your nephew's birthday.  You would be better off thinking about it first, and then getting a Uno, or probably a Mega, and some parts that are appropriate to your needs. You will get plenty of support here.
40  Using Arduino / Storage / Re: SD Card Module on: July 14, 2014, 07:07:28 pm
I though the module was ready to convert 5v to 3.3v. I'll try using a voltage converter and a better source

You are probably right, I think most SD modules are good for 5v, and it will pay to check before you do anything. It should be clear enough, with a pin labelled 5v. If it doesn't have a 5v pin, it might be simpler to pay up another $2.50 and get a module that does..
41  Using Arduino / Project Guidance / Re: Power between shields - VIN and 5v on: July 14, 2014, 06:42:12 pm
I am now looking to use the 5v pin and feeding down from a proto shield with its own barrel jack. It took a PM and some divine inspiration to realise that the normal feed to the W5100 via VIN is probably out of play if there is nothing on the Mega's jack.
42  Using Arduino / Networking, Protocols, and Devices / Re: Problem with Bluetooth on: July 14, 2014, 06:07:40 pm
Turn it over, look at the back, read what it says - twice, and then read reply #1 again.
43  Using Arduino / Displays / Re: Nokia 5110 LCD - possible broken [SOLVED on: July 14, 2014, 06:00:18 pm
My problem was little bit different. I did not connect through resistors. After I connect :
my screen start working

That's good, but I think your problem was more likely just a bad connection. I don't use any resistors.

44  Using Arduino / Project Guidance / Re: Power between shields - VIN and 5v on: July 14, 2014, 02:39:45 am
After the deafening silence, I am now starting to conclude this is a dead end.

I now have a 5v 2A powers supply. The objective is to power the whole stack from that.


I have tested it with just SIM900 on a Uno. I was prepared to settle for that, as I don't need the Ethernet for this particular exercise, but it appears that I have no chance, as the power is one-way.

There is a little slide switch next to the power jack. This has to be set to EXT in order to get external power to the board.  With the switch to EXT, the green light comes on as it should, but nothing is available on the 5v pin to go down to Arduino.

This strikes me as piss-poor design.  I guess one solution is to have a proto shield between the two, it has the 5v jack, the SIM900 shield is switched to Arduino, and the proto supplies 5v both up and down.

I still don't know if Ethernet gets to join the party.
45  Using Arduino / Project Guidance / Re: What bluetooth module do i need? on: July 13, 2014, 07:17:14 pm

RN52 bluetooth chip - has a2dp, hfp, hsp.

 the rn52 has a command line where you can give it a phone number to call

Perhaps that explains the $20.  It is not just a bluetooth module but, if that is what you want to do and that is what it does, then that is what you want, and it sounds cheap to me.
Pages: 1 2 [3] 4 5 ... 145