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751  Using Arduino / Project Guidance / Re: Temperature Sensing and logging on EEPROM - GUIDANCE!!! on: April 11, 2012, 03:54:46 am
Yes, "in principle"  smiley

When you remove the Arduino from where it was measuring to where you want to start listing measuremnets the measuring program will immedieatly start again when you apply power, and start overwriting the first set. So I suggest you put a wire between, say, GND and pin 12, and use the internal pullup resistor on pin12. The program tests on pin12 if this is a Measure&log session or a printout session. A jumper-switch in other words.
752  Using Arduino / Project Guidance / Re: Serial Communications Trigger on: April 11, 2012, 03:46:26 am
Thank you very much for the feedback. Good for the Forum, and really nice to know the suggestion made was usefull.
753  Using Arduino / Project Guidance / Re: Serial Communications Trigger on: April 10, 2012, 10:35:32 am
I do not know of a way you can "read" if the USB is connected or not, whether there is an appropiate program on the pc.

The screen shot shows PuTTY. Theres is a "enquiry" string you can send to PuTTY (and most other terminal emulators), and PuTTY will reply with some terminal info. If you do that in the Arduino in setup() you can then disable your serial debug/diagnstic routine.
754  Using Arduino / Interfacing w/ Software on the Computer / Re: Why does PuTTY hang my Duemilanove? on: April 09, 2012, 03:12:02 pm
Thanks, I may try that later.

I also may try and put a scope on some FTDI legs to try and guess what is happening. But may, just maybe, someone here already knows on an interpretetion of the control signals of the pseudo-COM port.
755  Using Arduino / Interfacing w/ Software on the Computer / Re: Why does PuTTY hang my Duemilanove? on: April 08, 2012, 01:53:24 pm
Eh? Not sure I follow your reasoning. If I use SoftSerial it will be on differnet pins and I have to use the USB/Serial adaptor cable. That is what I tried on the hardware lines (pin 0/1) and there it works fine as (unclearly?) described on earlier post. Putty & Serial monitor.

As far as switching hardware and everything my conclusion at this point is that it only fails if PuTTY is talking to that FTDI chip. And in some ways academic - the way I plug my Arduino into lots of experimental setups I am not surprised something breaks (it already is the 2nd chip on that board,  smiley-eek-blue I've blown the poly reset fuse 3 times, and the laptop has had a few emergency power saftey shutdowns, too  smiley-roll )

I have an old issue with my Mega not talking to Processing which smells of a similar problem (other programs talk fine with it, on others machine (OSversion) it works with Processing). This I am getting curious what is happening with the other control-lines ie DTR/CTS/DSR and so on.

(edit: added link to "old issue")
756  Using Arduino / Programming Questions / Re: where is the error ??? on: April 08, 2012, 01:01:12 pm
At this risk of sounding a bit overbearing - have you tried to understand what is happening with a "blocking" call? My explanation may not have been clear, sorry about that.

Try and use the "#" button on the input editor so your code comes in a box, ie is surrounded by the "code" brackets. (it is not just pretty that way, there are some formatting issues, too)

Meanwhile, the problem is that you still use
Code:
stepper.step(200);
which does 200 steps, and while doing so does NOTHING ELSE. SO you have to "manually" in your program alternate between one step with one motor and one step with the other motor in an apprioate ratio
Code:
stepper.step(1);

757  Using Arduino / Programming Questions / Re: asprintf replacement for arduino on: April 08, 2012, 06:02:13 am
Well, I did a text sdearch in my arduino code home, and found the HTML file that describes "libiberty", wherethe function is described. I can also see that the object file is there, but there is no ".h" defining the prototype. Defining one myself works for compiling but fails on link. So - and this is where I gave up - one needs to specfically ask to include the lib/libiberty.a file in the link.

On a completly different note: The microcontroller chip has limited RAM. Doing things with malloc etc works, but people who do so usually very quickly exhaust memory. And being a microcontroller, there is no pretty "program memory exhausted" message as the program exits, as there is nothing to exit to; It just keeps on running, looping, crashing, hanging until the reset button is pressed.

Handle your own buffers. smiley
758  Using Arduino / Programming Questions / Re: where is the error ??? on: April 08, 2012, 05:33:07 am
No, one Arduino can comfortably control several steppers. The typical 3D printer uses 4 motors and one Arduino.

Your code at the moment does something like
Code:
Move StepperOne 200 units
Move StepperTwo 100 units
What you need is something more like
Code:
Repeat 200 times:
  Move StepperOne one unit
  Has StepperOne moved an even number of times?
    Yes - Move StepperTwo one unit
So yes, the program suddenly becomes more complicated. In my example above I have assumed a fixed ratio (2-to-1). You can have any ration (a rational fraction to be mathematical correct) with a bit of integer math to decied if the slower stepper needs to move a step.
759  Using Arduino / LEDs and Multiplexing / Re: Fairly new, questions about power and LEDs on: April 07, 2012, 03:10:22 pm
1: No
2: No
3: RFID reading is a lot more difficult than powering LEDs ...

The Arduino single pin can only supply 40mA - and that will damage it in the long run. So you need a MOSFET to let something run the 200 to 600mA (depending on your LEDs). If you limit the LED current so that the total is under 300mA or so, then you could run it of the Ardiuno board suppy (the 5V pin), but it would be better with a seperate supply for the LEDs (which goes through MOSFET). The MOSFET gate can be directly controlled by the Arduino.

Plenty of examples around on this site (the Tutorial and Playground area)
760  Using Arduino / Programming Questions / Re: where is the error ??? on: April 07, 2012, 02:56:44 pm
( Not too happy about downloading a video file - would preer a YouTube or Vimeo link )

I'd prefer some better names rather than "stepper" and "mystepper" - Iike Xmove and Ymove or Swingarm and Lifter

The motors are doing what you ask them to: You move "stepper" a bot forward a bit backward. Then you move "mystepper".

The problem with the Stepper library is that the calls block - ie. no other code is executing while one motor moves. So the only way to get simultaneous movement is to call the two stepper motion with only one step, and the relative number of times you call them is the ratio you want the motors to move at.
761  Using Arduino / Installation & Troubleshooting / Re: Arduino Hangs and LED Switches On After Serial Monitor is Opened on: April 06, 2012, 03:39:06 pm
Rev 1 or 2. The bootloader integrity is beyond my immediate knowledge. I used Rev 022 of the IDE, but I am sure that is not of importance. Backward compatability and besides the pre-setup stuff is part of the core, not the bootloader.
762  Using Arduino / Interfacing w/ Software on the Computer / Re: Why does PuTTY hang my Duemilanove? on: April 06, 2012, 02:27:44 pm
Just also used my Mega which also uses the 8U2 chip. Same result testing as the UNO.

Update: Just setup the USB-FTDI cable, so I talk to the Duemilanove via the TX/RX pins and not via the USB port. Power is via external adaptor. And that works.

So something has fried something on the FTDI ... but I still dont get why it matters which software drives it? (tried all PuTTY setting with respect to DTR, CTS)
763  Using Arduino / Installation & Troubleshooting / Re: Arduino Hangs and LED Switches On After Serial Monitor is Opened on: April 06, 2012, 02:14:43 pm
I have a Mega 2560, an older Duemilanove, and a UNO. Loaded with the "Examples, Bare Minimum" from a IDE version 022, LED 13 is OFF whether I power on via USB or external supply.

I suspect you have a corrupted boot loader or something bust on your board. Look around for reloading the boot loader (requires a 2nd board or Programmer). Comming to think of it ... I do not know if you have the newer Opti-loader or the good ol' one (and I do not know how to check)

(BTW - I, too, have a mystical problem with a board behaving differently depending on the seriel connection - but sort of opposite to yours.)
764  Using Arduino / Interfacing w/ Software on the Computer / Why does PuTTY hang my Duemilanove? on: April 06, 2012, 11:15:41 am
I have an (older) Arduino Duemilanove and an Arduino UNO. The older uses the FTDI the newer the 8U2. My host systems are a Win XP and a Win7(64bit.) Drivers have been reintstalled/updated.

On both systems the UNO works fine, with SerialMonitor and PuTTY, I can run some simple Serial-echo program.
On both systems the Duemilanove does not work with PuTTY, but works fine with the SerialMonitor of the IDE. There also is no problem programming.

When using the PuTTY serial connection (on either host) the Duemlianove freezes. None of the LEDs flicker when Putty opens the serial connection. The reset button doesnt do anything either. I do not think it is my PuTTY settings, as I have used PuTTY a long time (occasionally) and had no trouble previously. (I have a video proving it), Unfortunatly I can not with certainty say when it last worked (as in - "what did you do when it stopped working")

Note: with the SerialMonitor everything works as expected (LEDs briefly flash, programs starts, resetbutton works)

The natural thing is to assume that the Duemilanove is damaged (?) but what/where/how? Some small speck of ironfiling stuck somewhere? And what does the PuTTY serial do that is soooo different to the SerialMonitor that it totally freezes (or loops or whatever)?
765  Community / Bar Sport / Re: Laws of the Forum on: April 06, 2012, 06:26:48 am
Getting back to the subject heading as I understood it (ie like Murphys Laws)

The 80/20 law: 80% of the threads cover 20% of the problem space.

Well, it is a bit exagerated, but these laws usually mention 80/20 (or 90/10)
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