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1  Using Arduino / Sensors / Re: Sound sensor - based on ZX-Sound on: December 21, 2012, 04:38:31 am
Indeed a nice board, but there is something wrong with the schematics. Pin 6 is the negative IN, not the positive. So either, the pin number is wrong and the signal is using the inverting entrance or the pin numbers are right and the signal is goint to the non-inverting entrance. Seems to me the latter is the most logical.

You say it is a 'modified' circuit. Look spretty mucg identical to the circuit from the ZX manual, but maybe I am overlooking something
2  Using Arduino / General Electronics / Re: ac dimmer guidance on: December 16, 2012, 10:01:48 am
just an addition: do not use the MOC3061 as that has a zero voltage detector and that is exactly what you do not want in this circuit
3  Using Arduino / Project Guidance / Re: Triac/Optocoupler Dimmer on: December 16, 2012, 08:24:33 am
Just in case someone ends up here looking for answers: have a look here:
It has a circuit with zerocross detection and software based on interrupt
4  Using Arduino / Project Guidance / Re: AC dimmer 220V 50Hz on: December 16, 2012, 08:21:09 am
further to my post of just now, the MOC3061 will certainly not be working in this circuit coz it is a zero-crossing optocoupler and that is exactly what you NOT want, as you pick up your zeroXing from the 4n35.  Use a MOC3020 instead.

Again, have a look here:
5  Using Arduino / Project Guidance / Re: AC dimmer 220V 50Hz on: December 16, 2012, 08:16:48 am
To be honest, I do not fully understand the code that you have written, but you may antto have a look here:
That has a working circuit+software

The circuit is probably not so much different from what you are using.
6  Using Arduino / General Electronics / Re: DIP replacements for SMD parts for light dimmer schematic. on: December 15, 2012, 06:33:21 pm
If you or anyone else are looking for a print design:
7  Using Arduino / Storage / Re: Reading microSD card directly from USB serial port on: December 15, 2012, 02:39:14 pm
I really do not see the problem here, but maybe that is just me.
The Arduino can read the SD card and send data to the serial port. A PC can receive data from the serial port.

Write a program (Visual basic even or pascal) that sends a 'send'  command (ctrl-s or whatever you like) to the arduini whereupun the arduino responds with reading the sd card and sending the bytes to the serial port. Your PC program then must be awaiting that data and do something with it (write it to disk, as bytes or as data directly in a CSV or database file). When the Arduino is done, he sends a code that the PC understands as 'done'

I have done something similar long time ago with an 8052 and Clipper on a PC. The 8052 upon command dumped its data memory to the serial port and the PC stored that in a clipper file.

Piece of cake.

8  Using Arduino / Project Guidance / Re: Dawn Simulator? on: November 04, 2012, 04:06:05 pm
is this one useful?
9  Using Arduino / Project Guidance / Re: AC lamps dimmer circuit on: November 04, 2012, 04:04:24 pm
something like this?
10  Using Arduino / Microcontrollers / Re: New optiboot; beta testers welcome... on: April 19, 2012, 01:36:54 pm
I still even have trouble for my IDE (both 22 and 1.0) to recognize the optiboot board. According to the instructions i do this:
To install into the Arduino software
1.Download the latest Optiboot zip file and extract it.
2.You will need to be using a recent version of the Arduino environment, version 18 or later.
3.Create a 'hardware' directory inside your sketches folder.
4.Copy the optiboot directory into the hardware directory.
5.Restart the Arduino software. New boards will appear in the Tools > Board menu.

But there are no new boards in the Tools > Board menu
Now I have done this for other boards and it always worked. If I look at the 'Optiboot' folder in my hardware folder, its structure is completely different from the ones that do work. Other folder (e.g. Attiny85) have a 'boards.txt' file in their folder and a folder called 'cores'. That folder then has a subfolder called Attiny85 again and only that folder then has all sorts of 'h',  'c' etc files in it. So not the optiboot folder: no 'boards.txt'  no cores folder, it just has all of its files (boot.h, makeall, makebat, pin_def etc directly in that one folder.

So, Am I forgetting something? Is there anything in the 5 line instructions that was too difficult for me to understand?

Yes, I did close and restart the IDE.
Anybody a solution as it seems to work for all you guys and calls.
11  Using Arduino / Installation & Troubleshooting / Re: Arduino Nano sort circuited-now dead. Is it the Scottky diode on: December 30, 2011, 04:41:52 am
Thanks. Yes, I thought about putting something more rsilient in it. at the other hand, now it sort of works like a fuse, a difficult to replace fuse.
I figure that a short with a more resilient device first and foremost cld lead to damage on the USB port. Maybe it is worth constructing a USB cable with a proper fuse.
12  Using Arduino / Installation & Troubleshooting / Re: Can't upload programs. on: December 29, 2011, 02:00:06 pm
I am sure you googled on it, but did you come across this page:;num=1287435600

What bootloader do you have?
13  Using Arduino / Installation & Troubleshooting / Re: Arduino Nano sort circuited-now dead. Is it the Scottky diode on: December 29, 2011, 01:50:41 pm
Applying 5V to Vin gave me a functioning Nano again, so I guess the culprit is clear. Remains the question if it specifically has to be the MBR0520 Scottky diode or that 'any' other Skottky would do as well ('any' = 'within reason', sort of comparable)
14  Using Arduino / Installation & Troubleshooting / Arduino Nano sort circuited-now dead. Is it the Scottky diode on: December 29, 2011, 01:22:04 pm
I know I am stupid but I shortcircuited the +5V and GND line on my Nano. My eyes are not that great anymore so I made a wrong connection on my breadboard.
Anyway, ever since, my computer does not recognize it anymore.
In an old thread ( ) I came across some people who had this problem as well and usually it is the Scottky diode that connects the Vusb with the 5V line: replace that and yr problems are solved.

Before I do that however, I had a few doubts and I was wondering if some people can maybe think along and give me some pointers.

  • I measured (with a MM) the diode and it still seems to have a low impedance in conduction direction and a high impedance the other way, like one wld expect with an intact diode
  • Nevertheless if I connect the USB, I measure 3 volts on the 5 V line (That line is directly connected to the kathode of the diode) and indeed 5V on the anode of that diode (which is connected to the USB supply line). 2Volts over a Scottky diode ofcourse is not OK.[\li]
  • Power led is still working, the Tx and Rx diodes only briefly blink at power up

Just to be sure I tried it on a different computer, the same problem.

So I actually had 3 questions:
Is it indeed possible that a diode 'blows' in a way that it still lets through current but obviously with a much bigger loss in Voltage? I thought that if a diode blew it wld either let all current through or nothing at all anymore.
If it is the diode, how critical is it to replace it with exactly the same one. Wouldn't basically any Scottky diode be OK?
Could it be anything else?

If this was all normal size, I wld have tried already, but with  50 yr old eyes and SMD, that is not something I look forward to.

Just to be complete (in case someone else is looking for a solution), I add a link to a picture of the underside of the board:  (hoover over the picture to see a note on the diode)
and here is the schematic of the Arduino nano:

My arduino does not look like that at all (a clone): In my case the diode is closer to the USB port, but as there only is one diode on the board, it should not be hard to find.

Your input is appreciated
15  Using Arduino / Programming Questions / Re: Trouble comparing a float variable in an If statement on: December 27, 2011, 10:10:05 pm
Thanks ajofscott, but I really want <=  :-)
It is a float variable and that will definitely become negative. I am looking at negative values now :-)

Nevertheless thnaks for your swift input
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