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31  Using Arduino / Networking, Protocols, and Devices / Re: Help with RTC DS1307, does not store the time when power off on: April 24, 2014, 04:27:17 am
Quote
I have the RTC DS1307 breakout board with the battery backup
Which one there are lots, can you provide a link to it?
32  Using Arduino / Sensors / Re: OV7670 writing to registers on: April 24, 2014, 03:08:10 am
Can you post all the code so we can see you reading and writing in the same code.
33  Using Arduino / Networking, Protocols, and Devices / Re: Help with RTC DS1307, does not store the time when power off on: April 24, 2014, 03:05:21 am
Have you got a battery backup circuit on that chip?
 You need one to keep the time live.
34  Using Arduino / Sensors / Re: Issue with infrared based circuit on: April 24, 2014, 02:40:20 am
Try clearing results.value in the if statement after the led blink.

It is a bad idea to have comments that do not match the code. How do you know which one is wrong?
35  Using Arduino / Sensors / Re: check water in plastic pipe on: April 24, 2014, 02:36:11 am
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As a proximity sensor you mean an ultrasonic sensor or a pir sensor?
No an inductance or capacitave sensor.
36  Using Arduino / Programming Questions / Re: the output pins are not effected by serial reading on: April 24, 2014, 02:18:48 am
Gather a number into a chr array. When you see a CR that is carriage return, replace that with a null  meaning a zero then use atof to convert it into a float variable.
37  Using Arduino / General Electronics / Re: filters with OPAMPs on: April 23, 2014, 10:17:29 pm
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So anywhere there is a positive connection place a decoupling capacitor.
Yes but the closer to the chip you can get the better.
38  Using Arduino / Programming Questions / Re: the output pins are not effected by serial reading on: April 23, 2014, 09:48:39 pm
A single char is not a string,
39  Using Arduino / General Electronics / Re: filters with OPAMPs on: April 23, 2014, 02:38:32 pm
Initial thoughts are that you have no decoupling anywhere.
You need 0.1uF caps across the supplies and across the vertuial ground resistors as close to the chip as you can.. Also put a large cap about 47uF as well.
Yes a solderd board will improve things.
40  Using Arduino / General Electronics / Re: filters with OPAMPs on: April 23, 2014, 12:07:28 pm
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But, what about low-pass filters or will it just add more noise to the signal, and it's not worth it.
It depends on the nature of your signal and where the noise is coming from.
If as I suspect it is due to poor layout and circuit then adding more poor circuits only make things worse.
41  Products / Arduino Due / Re: Arduino Due Unpredictable Analog Input Behavior on: April 23, 2014, 11:05:24 am
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The impedance is 50 ohms for all four channels (connected to an opamp output through resistor).
You sure of that it sounds very low for something coming out of an op amp.

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With regard to defining the variable based on a function... forgive me, but I don't understand why that would be an issue. Doesn't the compiler take care of that?
It is not your issue but I thought as you were worried about timing it might be relevant. A compiler can only do so much optimization and there is way too much there for the compiler to make any sensible guess as to how to cut the processing down.

I would initially suspect some sort of latch up in the internal multiplexers, have you checked your grounds and have you made sure that the voltage your op amps deliver are not greater than the 3V3 supply voltage of the chip or less than zero volts.
42  Using Arduino / General Electronics / Re: filters with OPAMPs on: April 23, 2014, 10:57:35 am
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The reason I thought high pass filter was because the OPAMP (as i understand it) works best when the frequency is higher rather than lower.
You understand it incorrectly.

If you filter before the amplifier when the signal to noise ratio is very low then yes you can end up with more noise.
However, improving the layout and decoupling around your circuit can greatly reduce the noise. Also using the correct component values, not just ratios will help.

So you need to post a schematic of what you have built for further help.

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but I don't know what are OP:s
Operational amplifiers
43  Using Arduino / General Electronics / Re: Wireless sound on: April 23, 2014, 10:52:34 am
Now when you say it doesn't work what do you mean:-
1) There is no longer any sound out of it.
or
2) I can not perceive any improvement in the sound?
44  Using Arduino / Networking, Protocols, and Devices / Re: Wire - Send values over 255 on: April 23, 2014, 10:45:13 am
Try doing:-
Code:
int S01index = 6;
unsigned long S01timestamp[] = {  13579, 1357, 135, 13, 1, 0 };
int S01reading[] = {  24680, 2468, 246, 24, 2, 0 };
and
Code:
for(int i = 0; i < S01index; i++)
45  Using Arduino / Microcontrollers / Re: FORTH pre-loaded UNO or NANO? on: April 23, 2014, 10:33:59 am
I have come across that board I was talking about. It is here:-
https://sites.google.com/site/libby8dev/fignition
It is available as a kit to build and is quite cheap.
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