There are alot of ways to do things in electronics with simpler circuits than use the Arduino, and I have learned that Grumpy Mike is definitively the guy to listen to when it comes to any circuit whether with Arduino or with out.

Since Arduino is a stepping stone into electronics for alot of people there are 30 dollar US ( or more ) solutions to things you can do for 5 dollar circuits.

But thats the fun of Arduino is it lets you do things when you couldn't before.

Heres a link to a blog post on just such a project Arduino and BlinkM Sound Visualizer It is sort of what your trying to do from your description, I hope it helps ya down the path on your project.

Also search google for "VU-Meter" or "light organ" those are similar circuits and the terms for what your trying to build.

BOZ

The bob leds are driven by the FT232RL chip as a side function to the rx tx serial transfer.


Here is a pic of the BoB as it hooks up to the standalone.



My concern was that a led circuit to ground would sidetrack the data flowing through serial rx tx, I need to send and receive data, on some projects, while still connected to the computer, not just for sketch uploading. I  was just concerned about data corruption and wanted to make sure there was any hidden traps.

Does not appear to be.

Thanks again.

Boz

Thanks I thought so, but was concerned there was some "hidden" noise garf I was missing or something, that someone might have had previous experience with.

The serial will still get through even with ground involved?

Thanks again

Boz

Built a perfboard arduino with the standard 6 pin connector (pin 1 grnd, pin 2 cts, pin 3 5v, pin 4 tx0, pin 5 rx1, pin 6 dtr) for programming (using a sparkfun bob)

Is there a led circuit I can put on or in between the atmega328 pin 2 ( pin 0 RX ) to interface pin 4 tx0 and atmega328 pin 3 (pin 1 TX) to interface pin 5 rx1 that can show serial activity without the chance of corrupting the data stream.

I know its simple but I want to make sure Im not missing any hidden downfalls, the sparkfun BoB has leds for activity but I want a second dedicated set on the standalone.

Thanks in advance.

Boz

Worked like a charm, Grumpy_mike, thanks, that was exactly what I was looking for.

One note I experienced in using  your Pin Change Interrupt call

Code:

PCattachInterrupt(7, rpm_fun01, CHANGE);

Versus the original hardware interrupt call

Code:

attachInterrupt(0, rpm_fun, RISING);

Is that it doubled my resulting rpm from the following equation

Code:

if (rpmcount >= 20) {
     //Update RPM every 20 counts, increase this for better RPM resolution,
     //decrease for faster update
     rpm = 30*1000/(millis() - timeold)*rpmcount;
     timeold = millis();
     rpmcount = 0;
     Serial.println(rpm,DEC);
   }

Output from Hardware Interrupt was 1200 rpm
Output from Pin Change Interrupt was 2400 rpm

I know this is because the CHANGE state measures both the switch from high to low and the switch back from low to high as a trigger each where the RISING call only triggers on the low to high switch.

I thought Id just mention it if anyone else doesn't catch it reading this in the future because the first version only supports CHANGE and not RISING and FALLING.

Thanks again for your help, I was this close <-> to switching to a much more complex I2C answer.

Boz

Very informative response, thank you very much.

My conundrum for my project is I have to measure four pulse sources, currently I have one on d2(int0) and one on d4(int1) I need two more. which is why I was looking for a "soft" interrupt.

I have to be careful in mucking about because I also have serial data back and forth (on d0,d1), pwm on 4 pins(d5,d6,d10,d11) and several addressables running on the I2C bus on pins a4 and a5.

EDIT: So upon further review, the clear answer is not with out mucking up a bunch of other stuff already using timers and interrupts.

Prolly goinng to move to some other hybrid answer from here.

Thanks again

Boz

Is there a way to duplicate the function of a hardware interrupt, pins int0/int1(digital pins 2/3) on other pins on the 328.

I know PWM can be "simulated" on non PWM pins and analog pins can be digital pins, Is there a similar way to "convert" a digital pin in software to function as an interrupt pin.

Im currently running the Reading RPM process in the playground at http://www.arduino.cc/playground/Main/ReadingRPM to read a fan.

But I need to do it on a different digital pin for a project where both interrupt pins (digital 2 and 3) are already tied up.

Any hints of where to look or code snips greatly appreciated.

For I2C you only need pins 4,5 and ground and power connected.

You upload sketches to each and use the wire library to talk to the slave and master.


Heres a few links

Using two lillypads
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1201476854/5#5

How to Connect Multiple Arduino Microcontrollers with I2C
http://hacknmod.com/hack/how-to-connect-multiple-arduino-microcontrollers-using-i2c/

And a link talking about dual core 168s
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1205243372

Hope that helps

Well now that you are rich and famous, need a partner?  Wink

Lefty

Rich and famous, phhhht, I keep forgetting not to use that sentence, "wow thats cool, Ill do it for free" or "how much do I have to pay you to let me do that".

Im always looking for other suc...., I mean collaborators, especially if your in the Bay Area of California.

Drop a pm if ya want.

I got my first arduino a year ago and started tinkering away, today I received my first parts orders with totals in the thousands  ;D

The Arduino team unleashed a fluffy bunny gizmo trojan horse of Open Sourcery.

It is both a blessing and a curse ;D

More info on my Arduino derivatives the Acore and Evolution after the beginning of the year.

I hope they add something back to the community that has already given me so much back of my past tinkering and fun.

Boz
http://www.musheen.com

http://twitter.com/Tinker_Tech
@Tinker_Tech

So, now that I have cried my heart out loud, I will go back to work with RXTX and the website, we are still building an open source project here, and there is a lot of work to do ... so thanks for the support, we will try our best to get you the best possible.

Thank you, thank you, thank you.

That should be a thread killer to the guessing right there

Thank You AGAIN and to the team.

/THREAD

You only need an Offical PID if you want a certain protection or certification.

In the capacity it is functioning in the uno it is like a UL listing in electronics. There are certain projects or situations where you cannot use an item unless it is ce or UL listed.

For example in my previous business of Haunted Houses I could not use a controller that was not ul listed or certified due to fire department and building codes (depending on enforcement).

Two weeks ago I could not have used an Arduino (legally to code) to control any aspect of lights or animatronics in a commercial haunt.

Now I can because of the UNO CE certification, of which the obtaining the USB VID PID was only one part.

Does that mean there weren't controllers that weren't certified that I used, in some smaller cities yes, but more large cities it had to be to FULL code and that meant nothing ran that wasn't certified by an Official certified governing body.

This discussion is the same, The UNO is now certified because of these steps. People are afraid they wont be able to build derivatives unless they pony up the USB license, thats not true, they can build derivatives exactally the same as they have and have them function in a non-certified manner) just as teh Arduino and anything else has for its full life.

You only have to pony up, if you want it certified. And that still has nothing to do with the VID/PID discussion, thats where the confusion is coming from.

The teensy has been running this way all along no problems and I bet is even the evolution of why we have the change in the chip in the first place.

BOZ

What have the "Fake" USB implementations (Igorplug, etc) been doing all this time, anyway?

There is an example in the thread, Paul Stoffregen uses this for the teensy

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1285500728/114#114

And thats why I said it is all kind of a moot point because the exact same thing will be how the 8u2 will operate in any derivative board.

And again, all of the pid issues are moot, there is no blocking point in reality, just in the panicked conceptualization of what if or maybe this could mean.