Show Posts
Pages: 1 2 [3] 4 5 ... 116
31  Using Arduino / Programming Questions / Re: loops / for /while/ect on: September 22, 2014, 08:34:43 pm
Indeed. Missed the obvious :-)

32  Using Arduino / Programming Questions / Re: loops / for /while/ect on: September 22, 2014, 07:11:25 pm
And, presumably, you put that code in the loop() function which is executed over and over, forever and anon.
If you want to stop your code executing just add
at the end.

P.S. it is etc. - not ect.
33  Using Arduino / Programming Questions / Re: Morse Code lights problem with delay and organization on: September 22, 2014, 03:58:40 pm
You are supposed to use code tags. Read How to post code properly
and fix up your first post otherwise I, for one, won't help.

34  Using Arduino / Project Guidance / Re: Using HamLib with Arduino on: September 21, 2014, 05:40:03 pm
If you can get the spec of the protocol used by the Navy radio, you could (with some effort) use the Arduino to translate between that protocol and one of the more common ones so that the Navy radio looks like an IC735, for example, to the logging software.

35  Using Arduino / Project Guidance / Re: Using HamLib with Arduino on: September 21, 2014, 05:04:57 pm
A brief look at the code suggests to me that it was written with the assumption that it was being run on a machine that had a large amount of ram to spare - on the order of MB or even GB, rather than kB.
It would be very difficult to get it to run on an Arduino. Just their driver for an ICOM rig, for example, would be too big for an Arduino.

Which rig are you trying to connect to and what do you want the Arduino to do?

36  Using Arduino / Project Guidance / Re: Responding to DTMF tones and generating tones in reply over phone line on: September 19, 2014, 07:09:00 pm
See my thread here:,121540.0.html

37  Using Arduino / Programming Questions / Re: GPS and eeprom problem. on: September 19, 2014, 05:46:51 pm
EEPROM.write only writes one byte to the address but it is not writing the first of the 4 bytes. The floating point number 48.356789 will be converted to an unsigned character, which will result in 48, and that will be written to the address.

38  Community / Bar Sport / Re: Scotland Reveals Currency Plan on: September 19, 2014, 03:43:37 pm
Bagpipes and haggis aren't dangerous weapons?

39  Using Arduino / Programming Questions / Re: Using the pow() function?? on: September 19, 2014, 10:30:19 am
create an exponential map
Do you mean draw a graph of an exponential function? If so, what sort of display are you going to use?

40  Using Arduino / Project Guidance / Re: Problem with FFT on: September 19, 2014, 10:26:23 am
for an academic requirement I need to understand FFT and then implement the algorithm in assembly
When do you have to have this done?
Writing an FFT in assembler when you don't even understand what an FFT is, is going to be mighty difficult.

41  Using Arduino / Programming Questions / Re: Compiler warning when using F() macro on: September 18, 2014, 03:24:51 pm
This thread might help:,102182.0.html

42  Using Arduino / Programming Questions / Re: Can't open file on SD card even though it exists on: September 18, 2014, 01:01:54 pm
When I compile this for a Teensy2 it reports that sram usage is 1543 bytes. If you have 2kB of sram this should be sufficient.

You have this code:
                    if(StrContains(filename, ".htm")) {
Are you guaranteed that webFile exists at that point? It might be best to use
which you have done elsewhere in the code.

43  Using Arduino / Programming Questions / Re: Can't open file on SD card even though it exists on: September 18, 2014, 12:38:07 pm
It would help if you showed what output you get on the serial monitor. It would also help to have a few more debugging statements. For example, add these as shown:
Serial.print ("filename = '");
so that you can see whether filename really is what you're expecting.

44  Using Arduino / Project Guidance / Re: I need 10 mbyte of ram memory for my arduino on: September 17, 2014, 02:30:14 pm
The W25Q128FV is a 16Mbyte SPI flash chip. I have played with a couple of them on the Teensy3.1 with the audio board adapter. The chip is about $3, in ones, from Digikey (which has the SOIC form, I don't know if/where you can get the PDIP which would be easier to breadboard).
I've done some simple measurements of the speed. Writing a 256 byte page takes 814us and reading a 256 byte page takes 429us (on average). This is with normal SPI. If you can figure out how to do it, you could use dual or quad SPI modes and really speed it up!
However, you won't be writing continuously to the chip at those speeds. Once you've filled it up, you would have to erase the chip in blocks of 4kB, 32kB or 64kB or erase the whole chip and each of these takes a comparatively long time to finish. I measured a  sector erase (4kB) at 90315us. The datasheet (page 86) says a chip erase typically takes 40 seconds, which is in line with what I have observed.

45  Using Arduino / Programming Questions / Re: 3D maths to sutract gravity from accelerometer data on: September 16, 2014, 09:32:35 pm
An object sat on the surface of the earth experiences a 9.8m/s^2
_upwards_ acceleration.
True, but it also experiences a 9.8m/s^2 acceleration downwards due to gravity. The two balance out and so the object doesn't move.

The fact it doesn't appear to move due to this acceleration is because we are accelerating
with it.
No. We aren't accelerating and neither is the object. If we were accelerating we'd be moving.

There are two opposing forces on the object. The earth's gravity trying to pull it towards the centre of the earth and the force of the ground pushing it up by exactly the opposite amount. If the two forces aren't balanced, the object will be moving.

The fact that we stay the same distance from the centre of the earth is because
space is curved.
No. The curvature of space around earth is caused by the earth's mass and the result of the curvature is what we perceive as gravity.

An object in free-fall has zero acceleration
That is a contradiction. An object in free fall is, by definition, accelerating.

Pages: 1 2 [3] 4 5 ... 116