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106  Using Arduino / Sensors / Re: pressure sensitive button - on: May 19, 2011, 05:55:32 pm
nice!
107  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 19, 2011, 05:51:50 pm
actually, the total current per channel is more likely to be around 250mA peak

but the same setup will should remain suitable..
108  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 19, 2011, 05:43:42 pm
"If you're not multiplexing, all you need is e.g. one or more of the 5947 chips. There is code for these chips on the macetech.com site. If you need the chips in DIP package, you'll have to use 5940, only 8 channels but there's a library for it as well."

But as I plan to power a group of leds on each channel totalling around 400mA, I can use a UDN2981A on the outputs of the 5947 right? and the UDN2981A wont have a noticeable delay in switching low/high that will mess up the pwm?

getting there!
109  Using Arduino / Sensors / pressure sensitive button - on: May 19, 2011, 04:37:18 pm
Hi

Does there exist something like a solenoid but in reverse?  So a moving shaft that give a varying reading (or resistance) depending on how far in the shaft is pushed?

I imagine that connecting a solenoid up in reverse you will only get a current when the shaft is moving. I need something more like a potentiometer, but in this format so it is strong, and I can experiment with different springs to make it return.

Any ideas?

110  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 19, 2011, 03:38:06 pm
Ok, so, am I right in thinking that if multiplexing, you can't use a ULN2003 because you need to switch the leds at the anode end to be able to address each led in the matrix?



If I'm not multiplexing, (which I don't really need to given the smallish number of leds I'm using) and use a TLC5947 to drive the leds with pwm, does it make no difference whether I use a ULN2003 type or UDN2981A type?

If so which is best (simplest ideally smiley and have you any links to info that will help get my head around the circuitry needed between the two (and the arduino)

Feel free to tell me to 'go search Google'!  There's just a lot of information out there..

Cheers
111  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 19, 2011, 04:59:58 am
I don't really understand this - "The ULN2003 will only sink current it will not source it."

-

How are the UDN2981A and TLC59213A different from the ULN2003?

-

And given that I don't need a very large number of leds, and I dont need them arranged in a square array, would I be better off with something like the TLC5940? 

And if so will this work with the UDN2981A or TLC59213A?


Thanks for being patient with my basic questions!
Will
112  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 18, 2011, 03:00:48 pm
Ah, one quick question, is it possible to use something the ULN2003A on these pwm'd channels to drive high current leds?

Thanks
113  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 18, 2011, 02:49:48 pm
Great thank you.

I will try to get my head round this.


Have you made anything similar? 
114  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 18, 2011, 11:51:57 am
And does this allow pwm for each led individually?

cheers
115  Using Arduino / General Electronics / Re: Stripboard template pdf on: May 18, 2011, 09:04:08 am
If anyone wants a custom version (within reason) let me know
116  Using Arduino / General Electronics / Stripboard template pdf on: May 18, 2011, 09:02:49 am
I knocked up a simple A4 size printable template to plan out stripboard design and attached it to this post.

Someone might find it useful
117  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 18, 2011, 08:59:22 am
Thanks for the link

I was looking at those Maxim drivers but didn't think any of them supported PWM.  Am I wrong?

Nice to know about the free samples!
118  Using Arduino / LEDs and Multiplexing / Re: multiplexing with pwm? on: May 18, 2011, 08:24:10 am
Thanks.

Possibly bit heavy for me currently but I'll try to digest it.


What's the hardware used?
119  Using Arduino / General Electronics / Re: Using one circuit to switch another - (basic!) on: May 18, 2011, 08:21:46 am
Yes that worked.

Thanks!
120  Using Arduino / General Electronics / Re: Using one circuit to switch another - (basic!) on: May 17, 2011, 09:25:07 am
The voltage is 5.9v  Will this be too much for the arduino pin?
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