Need help shrinking parts list from breadboard to Eagle board

Using Arduino General Electronics
#1

The "Ideal Eagle Components" would be those that are most common, least expensive etc.

[u]On My Breadboard Now[/u] [u]Ideal Eagle Component[/u]

  1. Arduino Micro on breadboard ATMEGA328 tqfp
  2. 16x2 LCD Hitachi type
  3. MOSFET to handle 12v
  4. 7805 for 12v to 5v
  5. Potentiometer for Contrast (Thumbwheel preferably)
  6. 10k resistors
  7. 3 Capacitors: 2 for decoupling 12v to 5v ( 1uf and 10uf currently, any recommendations?) And 1 across LCD power ( 1uf currently, any recommendations? )
  8. Slide Switch SPDT (fairly substantial, not too rinky dink)
  9. DC Power Jack for 12v, 4A
  10. Button
  11. 1N4001 Rectifier Diode
  12. ICSP Headers (not on breadboard now but needed for Eagle)
#2

Not sure what you're asking for.

#3
    1. 16x2 LCD Hitachi type SIP header?
    1. MOSFET to handle 12v Current requirements? If not too great a simple SOT-23 one would do
    1. 7805 for 12v to 5v LM1117-5.0 or equivalent in an SOT-223 package?
    1. Potentiometer for Contrast (Thumb-wheel preferably) Trim-pot?
  1. 10k resistors
  2. I use 0603, but if larger quantities are needed then 4x 0402 arrays are good.

-7. 3 Capacitors: 2 for decoupling 12v to 5v ( 1uf and 10uf currently, any recommendations?) 1206 ceramics or tantalum B

And 1 across LCD power ( 1uf currently, any recommendations? ) You can do those with 0603. Also lost of 100nF 0603's for decoupling of other components, like the Atmel chip.

    1. Slide Switch SPDT (fairly substantial, not too rinky dink) Shop around, find something that suits your needs.
    1. DC Power Jack for 12v, 4A 4A is a lot of current - you expecting to drop all that down to 5V?
    1. Button Purpose of button?
    1. 1N4001 Rectifier Diode Current rating and purpose?
    1. ICSP Headers (not on breadboard now but needed for Eagle) 3x2 0.1" header pins - pretty standard.
#4

I find 0805 chunky these days ;)

For the MOSFET (I'm assuming N-channel?) and that current level I'd up it to an SOT-223 or a D²PAC, and derate the current by at least 2x - that way you won't have to worry too much about heat. Quick look on Farnell UK shows this as a reasonable candidate: http://uk.farnell.com/nxp/buk9840-55/mosfet-n-ch-55v-sot223/dp/1769682 10.7A, threshold of 1.5V, Rdson of 0.04? at 5V.

For the power input I'd probably use 5mm-pitch terminal blocks.

For buttons, any tactile button would do - I often use the normal 6mm square jobbies, or I have some tiny little ones for other projects.

#5

3.5mm pitch screw terminals work well also and take up less space. http://www.digikey.com/product-search/en?pv89=216&FV=fff40016%2Cfff803bf&k=phoenix&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25 See the eagle con-phoenix-3.5 library (name is something like that)

#6

Intermittent pump will draw 4A when the MC tells it to turn on. I am wanting to power everything from one DC jack.

Is this a 5v pump?

A 4A PSU is not a trivial circuit if you need to drop from 12v to 5v. You'll need a switching reg chip, big inductor and large diode.

You say you are currently using "7805 for 12v to 5v", there's no way that's doing 4A.

Rob

#7

Graynomad:

Intermittent pump will draw 4A when the MC tells it to turn on. I am wanting to power everything from one DC jack.

Is this a 5v pump?

A 4A PSU is not a trivial circuit if you need to drop from 12v to 5v. You'll need a switching reg chip, big inductor and large diode.

You say you are currently using "7805 for 12v to 5v", there's no way that's doing 4A.

Rob

I think we'll find it's a 12V pump, hence the 12v supply and MOSFET. That's my guess anyway.

#8

Yes, on reflection that would make sense.

Rob

#9

For the diode, this one would probably be better than the 1N4001: http://uk.farnell.com/fairchild-semiconductor/mbrs340/diode-schottky-4a-40v-do-214ab/dp/2323112 It's a schottky, so has a lower forward voltage and a faster recovery time than a POS one.

For the button, if you want small, this is the one I use when I want to save space. I usually have 2 per board, one for reset, and one to enter the bootloader: http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1908243 Place them next to each other and you can enter the bootloader with one finger.

#10

Make sure the 4A traces are short and fat...

Don't pick components that you can't solder if you're building the board yourself(!) 0805 isn't too scary.

MOSFET - for 4A you want one with 0.015 ohm Rds(on) or less or it'll be pretty HOT Make sure its logic level.

Are you still using the Arduino Micro or doing a standalone ATmega328 circuit?

#11