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1  Using Arduino / Sensors / Re: Potentiometer input smoothing on: June 16, 2011, 11:38:04 pm
Just wire the 0.1uF capacitor between the analogue input pin and ground and attach your 10K pot as normal.
If things are getting shaky then add some supply decoupling.
I have never had to resort to averaging in software to get a solid reading off a 10K pot.

Wow, thanks, I've been struggling with this for ages. The addition of the second 47uF cap across the supply was the trick!! Had no idea it was that simple, or that two caps could be working at different frequencies like that. Flat, stable values now.
2  Using Arduino / Sensors / Potentiometer input smoothing on: June 16, 2011, 05:12:16 pm
I know how to smooth analog values in code, but I'm working on an application that sends multiple midi signals from multiple inputs, and all the averaging seems to slow things down a bit. I've got a 10k pot that I seem to remember was always pretty solid, but lately I've noticed the input is shaky.  Like I said I can average to some degree, but I'd really like to learn how to solve some of these problems on the signal side if at all possible.

I've read about low-pass filters, I've tried wiring one like this, (forgive my schematic skills) : 5V ++== A == OUTPUT == B ==-- GROUND  (A= 1k resistor B= 0.1uF capacitor)

However I'm still getting shaky input values. Any advice on what to try?
3  Using Arduino / Project Guidance / Re: long-life battery recommendations on: June 12, 2011, 03:35:04 pm
Battery capacity is rated in mah, so it's just a simple math exersice to determine what size battery is need for your two hour run time specification.

Ok thanks, honestly I'm fairly novice the calculation side of circuits...last time I tried to measure low-voltage current via multimeter it seemed like the math didn't work out. Would I have to measure it ahead of the Arduino's built-in voltage regulator?
4  Using Arduino / Project Guidance / long-life battery recommendations on: June 12, 2011, 12:03:42 pm
Sketching out a project that will employ 5-10 sensors to Arduino Diecimilia, likely using Fluxamasyynth to run some battery powered speakers. Size/weight of the power source isn't an issue, but it will need to run for several hours. Sensors will likely be flex, IR rangers, photocells. For whatever reason the 4 x AA pack just doesn't seem to me like it will have the endurance. Any advice would be appreciated!
5  Using Arduino / Installation & Troubleshooting / Sudden loss of serial port on: February 18, 2011, 01:26:42 am
OSX 10.6.3, MacBook Pro 2,1

I've used this Diecimila board successfully for quite a while now, and in the middle of a program today, using Firmata, I lost connectivity, and then could no longer find the tty/cu serial ports I've become so familiar with. This is the first time I've had this problem, but I have seen other people have it before.

I've spent a lot of time trying to find instructions on how to uninstall FTDI drivers, tried it several times, but never sure I'm actually fully getting rid of the driver entirely. I followed the instructions from FTDI, but I can only remove the kext, but never find the .pkg files it references in /Library/Receipts.

cd /System/Library/Extensions
rm -r FTDIUSBSerialDriver.kext
cd /Library/Receipts
rm -r ftdiusbserialdriver.pkg
rm -r ftdiusbserialdriverinstallerPostflight.pkg
rm -r ftdiusbserialdriverinstallerPreflight.pkg

So I repair permissions after deleting the kext and reboot. I reinstall FTDI driver, but during installation if I choose "Customize" I see that it is calling the installation an "upgrade." This makes me think I missed something on the uninstall. I reboot again, and still no ports when I plug in the Arduino. Blinking lights on the board and power indicator though when I plug in. What seems odd is that a couple of random times I've been able to get a port in Arduino, this 00000207D port (which is different from the one I'm used to.) When I list ports in Terminal I get something like:

tty.Bluetooth-Modem   tty.Bluetooth-PDA-Sync   tty.usbserial-0000207D

Then I start to think it's going to work. But when I try to upload the Firmata from Arduino, I see the serial lights blinking for a bit, but then they stall out too early, and shortly after I get:

avrdude: stk500_recv(): programmer is not responding

I've checked the board and tried both tty and cu ports. The last time this happened, I lost the port again and couldn't get it back by unplugging and replugging to the USB port, or anything.

Has anyone had any luck bringing their serial ports back on 10.6? Most of the examples I've found refer to older versions of OSX. Thanks in advance.
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