[germany]

Does anyone know a place in germany where I can order a couple of alcohol sensors. I can only find them in packages of 100 so far.

either the MQ-3
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/mq-3/List/0/SortField/4/ProductID/669/Default.aspx

or the TGS 2620
http://www.directindustry.de/prod/figaro-engineering/halbleiter-alkoholdampfsensor-29357-147468.html

or actually, anything will do at this point!

thankfully

fubbi

Hi

It's just a normal LED, not a high power one. I am confused now.

My resistor was based on 5V source voltage, 3.6V diode voltage, 30mA forward current

(5 - 3.6) / ( 30 / 1000 ) = 46.6 ohms

Wrong?? I dont want to kill my arduino!

http://www.produktinfo.conrad.com/datenblaetter/175000-199999/181154-da-01-en-LED_KLAR_10MM_WEISS_LED_10_80_000W.pdf

lol! what?

hi

I want to create a bright flash. I have a 80.000 mcd 10mm LED, and I really want to get the most out of it. The correct setup is a 47[ch937] R with the 5v from the arduino, but I would like to get the most out of it. Since it's just a 5ms on / 500ms off cycle I am hoping I can allow myself to "stress" the LED and get some more brightness.

Any ideas?

thanks

fubbi

Got it, thank you very much!

fubbi

hi, I am trying to figure out what the connectors on this board are called in europe

http://www.sparkfun.com/commerce/product_info.php?products_id=9259

I am hoping I don't have to order them from the US

help much appreciated

thanks

fub

most excellent sir

thank you

fubbi

Hi Mike

I get what you mean, but not what it means...

The SK3 has "+" and "-" connectors, "-" is not ground?

thanks

fubbi

SK3?

I have built the circuit exactly like in brakmolotov's example.

I can see the value going up and down between 0v and 5v nicely on pin 9 when I run his code.

But I am not getting past the transistor. When I measure at the output to the velleman I see a constant 6v

Any clues as to why this might be? Have I got something the wrong way around?

Thanks

here's the schematic

of course! thanks!

Hi

I have some common anode 7segment displays. I want a few segments to just be on permanently.

So i connect the anode to 12v in this case, and then I ground the respective segment.

My questions:

I guess I need a resistor, but I would have to add it on on the cathode side, is that okay? (12v -> segment -> R -> GND)

And for the one digit I want to control with the arduino, do I write a HIGH to turn it off and LOW to turn it on? (I am not bothering with a shift register, its just one display and it gets it's own arduino anyway)

Thank you!

fubbi

remember to place a big capacitor at the arduino output pin because the dimmer doesn't like the fast PWM pulses.

What kind of value are we talking about for the capacitor?

I am building a velleman dimmer controlled by a parallax ping. I am just about to connect them, I would really like to know this too before I hook it up.

fubbi

makes sense! thank you!

Hello

I am hooking up 4 solenoids, and I am trying to ad some big caps to
a. relieve the poor 500ma power supply
b. get more kick out of the solenoids

I have modified the tutorial solenoid pdf from the playground

http://fubbi.com/trans/solenoid.pdf

I got one cap connected, but when I want to connect the second i get a big spark.

I realize the first cap holds some current from my testing, but I still have a feeling I am doing something wrong...

thanks

fubbi