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151  Using Arduino / Project Guidance / 'Smash' in Eagle on: December 23, 2012, 12:58:37 pm
I understand that to move the name and value text of a component around you use the smash command but do you just leave the component smashed after you get everything moved and sized right or do you unsmash it?  I notice that when I unsmash a component after playing around with the text it all reverts back to the original placement and size.
152  Using Arduino / Project Guidance / Re: Crystal resonator question on: December 21, 2012, 10:29:09 pm

Yes, ceramic resonators are accurate enough for UART timing. I routinely use 3-terminal ceramic resonators in my designs, except when I need greater accuracy.

Good enough for me!  Thanks everyone!
153  Using Arduino / Project Guidance / Re: Crystal resonator question on: December 21, 2012, 02:24:13 pm
I just need it to be accurate enough to handle UART communication.  Will this work?
154  Using Arduino / Programming Questions / Re: Arduino GPS Shield by iteadstudio.com on: December 21, 2012, 11:55:28 am
yes the code i attached worked...
now i am trying this TingGPS example


i tried both baud rates 9600 (it was used in the demo) & 38400 the baud rate give in the data sheet..
but all i get is stars....
here's my results :

Testing TinyGPS library v. 12
by Mikal Hart

Sizeof(gpsobject) = 115

Sats HDOP Latitude Longitude Fix  Date       Time       Date Alt     Course Speed Card  Distance Course Card  Chars Sentences Checksum
          (deg)    (deg)     Age                        Age  (m)     --- from GPS ----  ---- to London  ----  RX    RX        Fail
--------------------------------------------------------------------------------------------------------------------------------------
**** **** *******  *******   **** *******    *******    **** ******* ****** ***** ***   0        0.00   ***   173   0         0       
**** **** *******  *******   **** *******    *******    **** ******* ****** ***** ***   0        0.00   ***   310   0         0
etc...

once again, thank you for your help, Paul  smiley

I don't know if anyone pointed this out to you yet but the reason you are getting stars is because these functions print stars if the data that it gets is invalid:
Code:
static void print_int(unsigned long val, unsigned long invalid, int len)
{
  char sz[32];
  if (val == invalid)
    strcpy(sz, "*******");
  else
    sprintf(sz, "%ld", val);
  sz[len] = 0;
  for (int i=strlen(sz); i<len; ++i)
    sz[i] = ' ';
  if (len > 0)
    sz[len-1] = ' ';
  Serial.print(sz);
  feedgps();
}

static void print_float(float val, float invalid, int len, int prec)
{
  char sz[32];
  if (val == invalid)
  {
    strcpy(sz, "*******");
    sz[len] = 0;
        if (len > 0)
          sz[len-1] = ' ';
    for (int i=7; i<len; ++i)
        sz[i] = ' ';
    Serial.print(sz);
  }
  else
  {
    Serial.print(val, prec);
    int vi = abs((int)val);
    int flen = prec + (val < 0.0 ? 2 : 1);
    flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
    for (int i=flen; i<len; ++i)
      Serial.print(" ");
  }
  feedgps();
}

static void print_date(TinyGPS &gps)
{
  int year;
  byte month, day, hour, minute, second, hundredths;
  unsigned long age;
  gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
  if (age == TinyGPS::GPS_INVALID_AGE)
    Serial.print("*******    *******    ");
  else
  {
    char sz[32];
    sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d   ",
        month, day, year, hour, minute, second);
    Serial.print(sz);
  }
  print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
  feedgps();
}

The reason the data is coming up as invalid is because all it is receiving from the GPS is 0xFFFFFFFF which means the GPS is putting out data but it doesn't have enough satellite fixes to output valid data.  You can see that the UART is receiving information from the GPS because in your data above you can see the number of characters received go from 173 to 310.  Once the GPS gets I believe 4 satellite fixes it will start putting out valid data.  Are you testing this inside?  Check out this video tutorial....it will help a lot:

http://www.jeremyblum.com/2012/07/16/tutorial-15-for-arduino-gps-tracking/
155  Using Arduino / Project Guidance / Re: Crystal resonator question on: December 21, 2012, 11:29:59 am
Actually I think I answered this myself.  This image: http://search.murata.co.jp/Ceramy/CatalogshowpageAction.do?sParam=CSTCE&sKno=G005&sTblid=A703&sDirnm=A07X&sFilnm=TRCMG4&sType=1&sLang=en&sNHinnm=CSTCE8M00G52A-R0&sCapt=Basic_Oscillation_Circuit
suggests that pin 1 & 3 connects to xtal1 and xtal 2 and pin 2 connects directly to ground.
156  Using Arduino / Project Guidance / Crystal resonator question on: December 21, 2012, 10:57:13 am
According to the datasheet for this:  http://www.mouser.com/ProductDetail/Murata/CSTCE8M00G52A-R0/?qs=sGAEpiMZZMsBj6bBr9Q9aTcK%252bRPmoof3TlNKu2LX2vU%3d

it says that the features include:

Features
1. The series has high reliability and is available
    for a wide temperature range.
2. Oscillation circuits do not require external load
    capacitors.
3. The series is available in a wide frequency range.
4. The resonators are extremely small and have a low
    profile.
5. No adjustment is necessary for oscillation circuits.

Does number 2 above suggest that I can just plug this in to the xtal1 and xtal2 without putting on those two little 22pF capacitors from each pin to ground as shown below?



Crystal by jg1996business, on Flickr
157  Using Arduino / Project Guidance / Re: Sizing a voltage regulator for an application? on: December 17, 2012, 06:12:46 am
back to the drawing board smiley-sad
158  Using Arduino / Project Guidance / Re: Sizing a voltage regulator for an application? on: December 16, 2012, 08:45:21 pm
uhhh....okay maybe not......I just put that part together in eagle and dang it is small.  I'm pretty sure I won't be able to solder that.  How are you supposed to use something that is in a package that is 1.5mm X 1.05mm? (6 PADS!!!)  Am I reading that datasheet correctly?
159  Using Arduino / Project Guidance / Re: Sizing a voltage regulator for an application? on: December 16, 2012, 07:56:34 pm
Thanks everyone for the help.  Just to be safe I think I am going to use this:

http://www.ti.com/lit/ds/slvs941e/slvs941e.pdf

Only needs three parts besides the ic and will fit in a small area.
160  Using Arduino / Project Guidance / Re: Sizing a voltage regulator for an application? on: December 16, 2012, 07:34:32 pm
Really? How will you control this? There isn't, typically, a "search for satellites" command that you send to the GPS. It searches for them when it feels the need, and it isn't going to tell you when it feels the need.

I read somewhere that 4 satellites are needed to get an accurate location.  I mistakenly thought that once it had 4 satellites (which I can read from the NMEA data that is being spit out), that it would come out of "search" mode.

Quote
The arrival of serial data does not, normally, wake a sleeping Arduino.

I was going to use this tutorial: http://rubenlaguna.com/wp/2008/10/15/arduino-sleep-mode-waking-up-when-receiving-data-on-the-usart/

Quote
Sleeping the Arduino, which uses very little power, while the GPS is sucking up power like there's no tomorrow seems a bit silly.

Probably right......I was thinking about battery life and trying to maximize it.

Quote
The 329-based Arduinos are typically 5.0V devices, unless you clock them at half speed - not a beginner project. Is the GPS a 3.3V device or a 5V device? Most are 5V devices.

I was going to use an mega328 with an arduino pro (8 mhz) boot loader.  The GPS and SD card both run on 3.3v so I figured it would just be easier to run the mega328 at 3.3 volts as well rather than level shifting everything.  I have a few other threads that I started to work through the issues associated with running an arduino at 3.3 volts.  I'm putting together the schematic in Eagle now and am hoping to post it on here before I send the board out to be made.
161  Using Arduino / Project Guidance / Sizing a voltage regulator for an application? on: December 16, 2012, 05:55:37 pm
I'm sure this will sound like a stupid question but I am wondering how much of a current buffer I would need to power the following devices? 

A2035 GPS Module - Peak Current = 49 mA
Mega328 - Maximum Current VCC -> GND = 200 mA
SD Card - ??? but I have read anywhere from 50 - 200 mA during a write operation
1 LED - 20mA

The program shouldn't ever have all devices operating at full power together.  Basically the GPS Module will be in full power tracking mode most of the time which the datasheet says draws 24 mA.  During peak current (when searching for satellites) I won't be writing any data to the SD Card.  I was thinking that I could put the Mega328 to sleep until it starts to receive the NMEA data through the UART.  Once it receives valid NMEA data it will write the lat and long position and time data to the SD Card.  I was hoping to run the whole thing off of a 3.7V LiPo battery and this 3.3v switching regulator which can handle up to 300 mA.

http://www.mouser.com/ProductDetail/Texas-Instruments/TPS62203DBVT/?qs=sGAEpiMZZMvAX9OfPh%252b2NdYypUYwsctEc%252bUiVMFRnng%3d
162  Using Arduino / Project Guidance / Re: How to solder an sd card connector to a pcb? on: December 16, 2012, 12:32:41 pm
Thanks everyone for all of the great suggestions!  And thanks to Duckie58 for the detailed explanation!
163  Using Arduino / Project Guidance / Re: Arduino Uno to program Mega328 with 8MHZ bootloader on breadboard? on: December 15, 2012, 11:09:32 pm

It's in the boards.txt file. In the IDE, as long as you pick one of the 8MHz boards when burning the bootloader and then also the same one when uploading a sketch, you shouldn't have to set anything.

Awesome!  Can't wait to try it out!
164  Using Arduino / Project Guidance / Re: How to solder an sd card connector to a pcb? on: December 15, 2012, 09:26:11 pm
Quote
I reguested a sample from 3M and I will probably print the part out on paper and see if everything lines up before placing it on a board. 
Be careful how you do that. Plotting the part would be accurate. Printing it may not result in a 1/1 scale.

I'll have to print a known part next to it, something in a dip package, to verify that the scale is correct.
165  Using Arduino / Project Guidance / Re: How to solder an sd card connector to a pcb? on: December 15, 2012, 08:58:32 pm
Thanks everyone for the suggestions.  I actually found these on Mouser that have the tabs on the back which should be a lot easier to solder:

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtmXftMXMXEVuQEcuZgVs6EVs6E666666--

I've been making a part for it in eagle and I think I have all of the spacing of the pads worked out.  I reguested a sample from 3M and I will probably print the part out on paper and see if everything lines up before placing it on a board. 

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