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1066  Using Arduino / Programming Questions / Re: Memory Leaks (SD and Strings) on: July 27, 2012, 10:20:52 am
Change your code so that it does not use the String library at all. There is a bug in the library.

Pete
1067  Using Arduino / Sensors / Re: Temperature changing with different power sources. on: July 27, 2012, 09:36:50 am
In the circuit diagram, why do you have a resistor going from Arduino ground to the ground rail on the breadboard?
If that is the only connection between the two grounds, it is wrong. It should be a wire.

Pete
1068  Using Arduino / Sensors / Re: Temperature changing with different power sources. on: July 26, 2012, 12:20:37 pm
Monitor the voltage on the 9V battery to see if it is dropping as the temperature rises.

Pete
1069  Using Arduino / Networking, Protocols, and Devices / Re: Arduino relationship with eeprom AT24c01 on: July 25, 2012, 07:24:10 pm
Don't crosspost.

Pete
1070  Using Arduino / Storage / Re: help me. Arduino with eeprom AT24c01 on: July 25, 2012, 07:21:45 pm
Quote
the process of reading data at address 0x57 is data that appears in the address 0x50.
That's right, because changing the address of the chip does not change its size.
If you write 'A' into address 0 when the chip has address 0x50 and then read address 0 from the chip when it has address 0x57 you will get 'A'.
If you have more than one chip you can install them with addresses 0x50, 0x51, 0x52 and so on. Then if you write 'A' into chip 0x50 at address 0, that will not affect what is in address 0 in the chips at 0x51, 0x52 etc.

Pete
1071  Using Arduino / Project Guidance / Re: Keeping track of the Date and Time despite power loss on: July 24, 2012, 01:38:28 pm
Would a Chronodot be suitable?
http://macetech.com/store/index.php?main_page=product_info&cPath=5&products_id=8&zenid=8842c362d4426207f9b41188addabf62
I2C and +/- 2ppm accuracy.

Pete
1072  Using Arduino / Programming Questions / Re: GMT Time Conversion on: July 23, 2012, 04:05:56 pm
Quote
GMT time conversion to Pacific time (UTC to PST [-19 Hrs])
GMT to PST is -8 hours. I'm in the CST zone which is GMT-6 so PST is two more hours behind that.

Pete
1073  Using Arduino / General Electronics / Re: M shaped waveform using Chebychef lowpass filter? on: July 19, 2012, 02:40:06 pm
Quote
My goal is to generate a waveform that has a shape similar to an M rather than a sine wave.
Why? What is it going to do for you?

Pete
1074  Using Arduino / Programming Questions / Re: TimerOne Library: strange beahviours on: July 18, 2012, 06:24:39 pm
You can't use Serial.println in an interrupt routine.

Pete
1075  Using Arduino / Programming Questions / Re: Computation takes a long time on: July 16, 2012, 10:51:27 pm
Declare all your variables, such as r1v and r2v, outside the for loops. Every time you enter the inner for loop the code has to create space for those variables on the stack and then pop them off at the end of the loop. Then immediately pop space back on again the next time through.
That should speed it up a bit.

Pete
1076  Using Arduino / Programming Questions / Re: Improve code, Interrupt? [ADVICE] on: July 15, 2012, 11:36:08 am
Why have you defined xButtons to be 11 when your arrays only have 10 elements?

Pete
1077  Using Arduino / Sensors / Re: DS18S20 serial output => 3.31 ? on: July 15, 2012, 10:59:06 am
The circuit diagram you link to shows the DS18S20 wired in non-parasitic mode but your code requests the temperature in parasitic mode. If the code and the wiring aren't consistent the readings you get may not be reliable.

Pete
1078  Using Arduino / Project Guidance / Re: Opening a Geocache on: July 10, 2012, 12:05:31 pm
Try googling for "reverse geocache". For example:

Pete
1079  Using Arduino / Storage / Re: Reading specific lines from SD on: July 08, 2012, 08:25:29 pm
If the lines are different lengths, the only way to do it is to start at the beginning of the file, read each line (using fgets) and count them until you get to the 15th one.
If every line is the same length, there are seek functions you can use to position the file just before the first character of the 15th line and then read however many characters are on the line.
I haven't tried it myself so I can't give you a working example but look in the SDfile Class Reference for the seekSet function.

Pete
1080  Using Arduino / Networking, Protocols, and Devices / Re: Some help with DS1307 on: July 08, 2012, 11:51:28 am
Something is obviously flaky but it doesn't appear to be the clock. I'd suggest that you remove all the wiring and start again.

Pete
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