Fader Controlled 10 LED Bar (LED Driver Help)

I am trying to find/build a circuit to control 10 LED Bar which is lit by the value a 10K fader.

http://www.arduino.cc/en/Tutorial/LEDDriver
This example is almost perfect except:

  • I cant find a Phillips 4794 on gb.mouser.com
  • The Phillips 4794 only controls 8 LED’s

Mouser do a CAT310WT1 (Product Code:698-CAT310W)

Manufacturer: Catalyst / ON Semiconductor
Product Category: LED Drivers
Number of Segments: 10
Package / Case: SOIC-8
Operating Supply Voltage: 3 V to 5.5 V
Maximum Operating Temperature: + 125 C
Minimum Operating Temperature: - 40 C

Manufacturer Website: http://www.onsemi.com/PowerSolutions/product.do?id=CAT310W-T1
Datasheet: http://www.onsemi.com/pub/Collateral/CAT310-D.PDF

Would this driver be able substitute the Phillips 4794 the original example?

Thanks in advance

Hi Guys,

I must be doing something wrong as my post seem to go unanswered [smiley=angry.gif] In-order to complete my two main circuits i am going to need the advice and help from people with knowledge of connecting IC's to arduino.

10 LED Bar: Ideally i would like it connected directly to the fader as a visual reference of the fader value/position, The arduino will only be reading the resistance value of the fader and not controlling the LEDS.

The LEDs will be positioned evenly along the length of the fader so the knob will more or less in-line with the lit LED's. Example: - Fader half way up = 5 LED's lit up!! - Fader all the way up = all LED's lit up!!

i have mentioned a similar example in my previous post.

On another forum it was suggested that i use a LM3914 http://cache.national.com/ds/LM/LM3914.pdf

Being an IC I have no idea how to connect it to my arduino and LEDS.

PLEASE can someone help me with Suggestions, Comments and Advice.

Thanks in advance

Darrell

I must be doing something wrong as my post seem to go unanswered

A lot of people are not around at the weekend, also posting twice implies that you have had a reply and some people are incline look at posts like that. Finally it is rather a complex and specific request. It requires that one first looks at the tutorial, then looks at the replacement chip and maybe devises and draws a circuit to use the new chip in the old tutorial, maybe even the software is different. Without trying these things out in practice it is impossible to grantee the advice is correct.

Being an IC I have no idea how to connect it to my arduino and LEDS.

What you have to do is to look at the data sheet. That usually shows a "Typical application" circuit. Then you go round all the pins and make sure you understand what the do and decide if you need to connect it up as an input or output to the arduino. The LM3914 for example will not need connecting to the arduino at all as you can simply connect it to your pot through the signal input. The only problem is that it requires at least 6.8V (page 2 of data sheet) so you can't power it up from the same 5V as the arduino. However it will do exactly what you want.

The CAT310WT1 looks like a suitable substitute but the data sheet says you can only get it in a surface mount package, can you handle that?

cheers mike,

have made the diagram using fritzing.

Would i be correct in saying that the "0-5v Signal is the power coming from the fader?

Is the wiring correct?

Thanks again for your help

Would i be correct in saying that the "0-5v Signal is the power coming from the fader?

yes.

Is the wiring correct?

I hate physical wiring diagrams it is so difficult to tell what they are supposed to do and very hard to read. You don't even say what chip you are using. Assuming it is the LM3914 implementing the diagram on page 2 then no it is wrong. The wiring is messed up round pins 6, 7 & 8

Cheers for the help, its much apreciated.

I hate physical wiring diagrams it is so difficult to tell what they are supposed to do and very hard to read. You don't even say what chip you are using. Assuming it is the LM3914 implementing the diagram on page 2 then no it is wrong. The wiring is messed up round pins 6, 7 & 8

The chip is the LM3914 i still have to make the svg file I have reworked the layout

That's better. I would add the capacitor across the LED supply and another between pins 3&4 of the chip.

Thank you very much!

That's better. I would add the capacitor across the LED supply and another between pins 3&4 of the chip

Do you mean connect pins 3 & 4 together? or add to each pin (between pin 4 & GND & 3 & V In)?

Note: Grounding method is typical of all uses. The 2.2[ch956]F tantalum or 10 [ch956]F aluminum electrolytic capacitor is needed if leads to the LED supply are 6" or longer.

Reading this i thought i wouldn't need the capacitor as it will be on a PCB next to a 7cm (2.75 inch) Fader.

Is this thinking correct?

Is this thinking correct?

No. In the sort of wiring environment you have you should use all the decoupling you can.

Do you mean connect pins 3 & 4 together

No. Put a capacitor between these chips 0.1uF should do.

sorry for my lack of knowledge, but now im confused:

No. In the sort of wiring environment you have you should use all the decoupling you can.

I don't understand what decoupling is!! (Will do a bit of gooling)

No. Put a capacitor between these chips 0.1uF should do.

Do i do this if i am using multiple circuits?

I hope im not annoying u with silly novice questions?

Decoupling:- http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

Put a capacitor between these chips 0.1uF should do.

Sorry I meant to say pins not chips. So put a 0.1uF capacitor between pins 3 & 4. This is decoupling the chip and is important so that it works without interference disrupting the chip.