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2131  Using Arduino / Networking, Protocols, and Devices / Re: Using an arduino uno and wifly rn 171 to create a wifi traffic emulator? on: April 26, 2013, 12:28:02 pm
Quote
The purpose of the device is just to broadcast wifi packets from one wifly to another. nothing more, just have traffic exist over a two node communcation.

That's not a purpose, that's how you want to do it. Is the purpose just to fill the WiFi spectrum with noise? I don't see any sense in sending random data from one node to the other. Even if you measure the bandwidth you might get with this hardware combination, that data won't have any value because you cannot transfer these measurements to a PC you might install in the same area.

BTW: you cannot generate enough data with an Arduino to even fill an 802.11b network.
2132  Using Arduino / Networking, Protocols, and Devices / Re: Proxy Authentification with Arduino Uno + Ethernet Shield on: April 26, 2013, 10:09:52 am
Quote
How do I add the Proxy-Authorization header?

The same way as you add p.e. the "Host" header line. Show us the code you're using if you want more help.
2133  Using Arduino / Networking, Protocols, and Devices / Re: I2C with 15V @ Arduino? on: April 26, 2013, 09:46:17 am
If the I2C interface is really driven with 15V you need a level converter to interface it to the Arduino. Are you sure the I2C pins (SDA/SCL) are on 15V? What does the multimeter tell you? The 15V might be the power supply for the device.
2134  Using Arduino / Networking, Protocols, and Devices / Re: Proxy Authentification with Arduino Uno + Ethernet Shield on: April 26, 2013, 09:16:09 am
Quote
I know that the Arduino doesn't support the usage of a proxy natively.

The Arduino doesn't even support HTTP natively. You use an HTTP client and put the whole URL into the GET request (not only the local path but also the protocol and host name parts) and add the Proxy-Authorization header as specified in RFC2616 (HTTP protocol). You connect to the proxy and not the server the URL is pointing to.
2135  Using Arduino / Networking, Protocols, and Devices / Re: Using Multiple MCP23S17 as slaves on: April 26, 2013, 09:08:26 am
Next time please include links to the datasheet of your device (http://ww1.microchip.com/downloads/en/devicedoc/21952b.pdf).

The address pins are bits not addresses. Show us the code you're using and draw a diagram or make a picture of your wiring.
2136  Using Arduino / Networking, Protocols, and Devices / Re: Arduino Ethernet Freezes on: April 26, 2013, 08:30:07 am
You don't do lots of error handling. Try replacing your line:

Code:
client.println("GetStatus=1");

by

Code:
client.clearWriteError();
client.println("GetStatus=1");
if (client.getWriteError()) {
  client.stop();
  Serial.println("Client write failed, stopping.");
}

Does that change anything?
2137  Using Arduino / Programming Questions / Re: SIN COS TAN Decimal Precision for 32-bit Float / 64-bit Double Arduino on: April 24, 2013, 04:31:16 am
Quote
My question was two-fold, one to determine the number of decimals we can reply upon for the Due board, and secondly, how accurate are the trig functions themselves? Do the trig functions reduce the decimal accuracy, and if so by how much? Thanks again for the help.

You wrote that you know the floating point model to describe a number. Even in the decimal system you loose some precision with every calculation you make (because there's almost always some rounding to be done). The same is true for the binary version of the same model.  You loose about one bit per multiplication you do. The trigonometry functions are almost always implemented as Taylor approximations, which includes many of these operations. An estimation of the overall precision is only possible if you have the final code and now the versions of the libraries (trigo) used and such an estimation is rated complex and time consuming, so they are an overkill if the precision is not deathly critical.
In most standard cases (some calculations with a few trigo functions) you can use 3 to 4 decimal digits as a rule of thumb.
2138  International / Deutsch / Re: Schema des Arduino Ethernet Shield on: April 24, 2013, 04:14:29 am
Du hast Recht, das Board-Layout der Version 6 entspricht R2 und nicht R3. Allerdings weiss ich auch keine Downloadmöglichkeit für eine aktuellere Version als die 6.
2139  Using Arduino / Programming Questions / Re: Serial monitor converting to 32 bits? on: April 23, 2013, 11:47:03 am
Quote
Seems to me to be a bug in the Print class though because your experimentation shows that there is no way to predict what the new 16 bits will be that the Print class pads when it casts the input int as a long.

No, this is not a bug, it's standard behavior. And you do print a 16 bit integer. My guess is you don't want to print a 16 bit integer but you want to print the 16 single bits of that integer. Am I right?

Try this slightly modified code:

Code:
void print_i(uint16_t i) {
   Serial.print(i,HEX);
   Serial.print("\t");
   Serial.println(i,BIN);
}
2140  Using Arduino / Networking, Protocols, and Devices / Re: Can the Uno handle two serial port functions ? on: April 23, 2013, 11:41:54 am
I still have no picture of how you have wired your project. Is that button control panel only sending data or do you have to send some commands to that panel? Do you have a link to the datasheet of that panel? Why do you need an Arduino?
2141  Using Arduino / Networking, Protocols, and Devices / Re: RF and PC connection on: April 23, 2013, 11:35:20 am
You give us the information in small bits. Provide all the information you have. What do you want to achieve? What sensors do you expect to use? Why does it have to be two RF modules?
2142  Using Arduino / Networking, Protocols, and Devices / Re: Define password and username variables using a WiFi Shield on: April 23, 2013, 11:32:41 am
The RN-171 from Roving Networks (http://www.rovingnetworks.com/products/RN171) has a SoftAccessPoint feature with newer firmware versions. Using this feature you could establish your own WiFi network to let the user configure the installed (router's) WiFi network.

Quote
Actually, do you find that weird to do that?

Yes, I probably would classify it weird to include a separate wireless technology just to configure a device, which is not used anymore after that point.
2143  Using Arduino / Networking, Protocols, and Devices / Re: Using an arduino uno and wifly rn 171 to create a wifi traffic emulator? on: April 23, 2013, 11:23:04 am
What's the planed purpose of this device? How much traffic do you expect it to generate?
Remember: the device gets it's data from the microcontroller by a serial interface.
2144  Using Arduino / Programming Questions / Re: Serial monitor converting to 32 bits? on: April 23, 2013, 08:43:13 am
The implementation of print(int, int) in the Print class is as follows:

Code:
size_t Print::print(int n, int base)
{
  return print((long) n, base);
}

So 16 bit integers are converted to 32 bit integers before printing.
2145  Using Arduino / Programming Questions / Re: SIN COS TAN Decimal Precision for 32-bit Float / 64-bit Double Arduino on: April 23, 2013, 08:36:18 am
Quote
I want to know what kind of true decimal precision I can reply upon on after a single SIN, COS or TAN calculation for both of these boards using Float or Double. Thank you in advance for any assistance.

The 6 to 7 decimal digits precision of a float is a good approximation, the Due's double has about twice that (13 - 14), but by asking the question you reveal that you probably haven't understood the concept behind a floating point number. Let's say we had a precision of 4 decimal digits. Then the number 13 may be represented by 12.999 and that's within the precision although only one digit is equal to the exact number you would have expected.
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