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31  Using Arduino / Project Guidance / Re: Peltier cooling temp control- photographic application on: October 02, 2011, 09:09:32 am

The pictures on that page are impressive - I hope you achieve something similar!
32  Using Arduino / Project Guidance / Re: Peltier cooling temp control- photographic application on: October 02, 2011, 04:06:25 am
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Q: why do you want to cool the camera so much ? special effects? sensitivity? ...

Sometimes when you are doing long exposures (really long) you get extra sensor noise from the heat that is generated from the process of capturing the image. Astrophotographers come across this problem quite a lot I believe, so maybe geoland is doing something similar.
33  Using Arduino / Project Guidance / Re: USB through tiny hole in box; FTDI breakout boards? on: September 25, 2011, 11:20:52 am
Good job with the board in the photo, it looks really slick.

If I understand you correctly, perhaps it would be worth quickly knocking together an FTDI breakout board of your own, and adding the appropriate holes to connect the chip to the emasculated USB cable.

It shouldn't be too hard to solder that chip with a bit of solder paste and an iron and you solve the problem of having to somehow thread a connector or having to solder the wires to the small connector pads - much more mechanically reliable.

What's the USB used for - just for programming or for control etc?
34  Using Arduino / Programming Questions / Re: Press button action. And press and hold button action on: September 25, 2011, 10:43:37 am
To the original poster - http://jmsarduino.blogspot.com/2009/05/click-for-press-and-hold-for-b.html
35  Using Arduino / General Electronics / Re: 12 V Rechargable battery on: September 25, 2011, 08:50:17 am
To get a rough idea of current usage you could hook up a multimeter in ammeter mode.
36  Using Arduino / Microcontrollers / Re: Arduino style board for AtTiny2313 on: September 19, 2011, 03:21:01 pm
I like the option to choose between 3v3 and 5v, but I would be worried about accidentally changing the switch to the wrong setting and breaking something. Any chance of a jumper? Or a few holes to put pins for jumpers?
37  Using Arduino / Networking, Protocols, and Devices / Re: Mpr121 capacitative keypad w/ logic level converter on: September 19, 2011, 02:25:20 pm
From the looks of the schematicon the SparkFun site you should use the two TX lines for the level conversion, and ignore the RX lines. Connect the 3v3 to the LV side, and the 5v to the HV side.

If this doesn't work, then there's something else wrong with the setup or the code.
38  General Category / General Discussion / Re: Arduino 1.0 Soon - What do you want to see? on: September 17, 2011, 01:50:00 pm
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We’ve made some minor additions to the Arduino connectors to make them more flexible.

Does that mean they've fixed the pin spacing?
39  Using Arduino / Networking, Protocols, and Devices / Re: Mpr121 capacitative keypad w/ logic level converter on: September 17, 2011, 06:16:34 am
Always connect the grounds together, otherwise nothing will work properly.

To use this method, connect two appropriate MOSFETs (maybe a 2N7000?) in-line with the SDA and SCL lines, with their gate pins tied to 3v3. The source side should be towards the high voltage, the drain side to the 'high' 5v voltage.

As for using both 5v and 3v3 from the Arduino at the same time, yes you can, not a problem. A large breadboard which has the split power rails might be useful for this to help separate.

If you want to stick with the logic level converter, what's the part number?

Edit: If anyone can't be bothered to download the PDF, here is the circuit diagram. There is a textual description in the PDF which might be useful.
40  Using Arduino / Networking, Protocols, and Devices / Re: Mpr121 capacitative keypad w/ logic level converter on: September 16, 2011, 02:49:57 pm
Check page 43 of this PDF (i2c spec).

Does that help with the problem?

Link courtesy of this page.
41  Using Arduino / Networking, Protocols, and Devices / Re: Mpr121 capacitative keypad w/ logic level converter on: September 16, 2011, 02:31:10 pm
I was under the impression that i2c didn't require a voltage level converter as it is the pull-ups that provide the high voltage, and the SDA/SCL pins only connect the line to ground when required. Just use the 3v3 supply for the pull-ups, which I think are included on the board?
42  Using Arduino / Microcontrollers / Re: 556 dual led flasher? on: September 09, 2011, 06:32:30 pm
Could you not just use the 555 timer in the standard astable configuration?

Then just link up the LEDs so they light alternately as in the attachment, presuming that is what you are after.
43  Community / Website and Forum / Re: TapaTalk... on: September 08, 2011, 06:48:15 pm
Would it not make more sense to simply install a mobile-device-friendly theme as an option for users to choose?

Doesn't require any special software.
44  Using Arduino / General Electronics / Re: Arduino PCB question on: September 06, 2011, 06:23:02 am
It might be that the leads on the part are too fine a pitch for the PCB fab service you have selected, and there might be issues when making the boards.
45  Using Arduino / Project Guidance / Re: ATMega Surface mount on: September 03, 2011, 03:39:53 pm
Eagle should have one. Look in the Atmel library for the Mega8 part.
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