How to build a micro-controller Dev. board ??

schreef in bericht news: snipped-for-privacy@h54g2000cwb.googlegroups.com...

Well... The manual provides both a component layout and a schematic. You just have to skip the things you don't need. Nevertheless, you can't gain very much space as the current board is pretty small already. Moreover designing a crowded PCB like this is not a beginners job. Guess you can go to half the current surface at best unless you can use SMD parts.

petrus bitbyter

You might want to look at Atmel App. Note AVR042 "Hardware Design Considerations" - that covers power supply, clock sources and connecting the ISP lines. That's all you need to make it run, the rest is hooking up the right I/O pins to the rest of your circuit and programming it.

Tim

Have you looked for a kit on eBay?

I have a promotional email at work for the latest dev board for the ATMega series and it's pretty small and inexpensive.

I'll post a link tomorrow morning.

Cheers

PeteS

petrus, I'm not familiar with SMD parts, but as far as I know they have different power specs. Anyway, even if I can build one that is half the size of the current on this will great. Another thing is that I don't really know what things I don't need in the manual and that's why I'm trying to get help here.

Thnx

That should be easy. Just take the existing schematic and remove every item you don't need, then re-layout the board to make it as small as possible. You board should need nothing but an ISP serial header for programing, an I/O header, an oscillator, and a voltage regulator. You can even leave off the voltage regulator if you already have 5V available.

Think about what items you aren't physically connecting to at the moment, and you can simply remove then, the micorcontroller won't care. As long as you can a)program the chip, and b) access the I/O pins you need, that is enough. That board has a lot of wasted space, with lots of jumpers, and LEDs and resistors that presumably you won't need.

Dave :)

The might have different power *dissipation* specs - ie they get a bit hotter when dissipating a given amount of energy, but that's only really of concern for stuff like power transistors and voltage regulators, which will be dissipating a fair bit of heat while doing their job. An SMD ATmega32 has just the same silicon inside as in one in a DIP package.

Tim

schreef in bericht news: snipped-for-privacy@f16g2000cwb.googlegroups.com...

But you have the board and used it? So you have the manual of the board as well *and* you know what ports and pins you need. Suppose you use half port A for the analog and port C for the digital. So you have to keep JP1 and JP6 half. You can leave out JP2 with the resistors and the LEDs, X1 with JP3, JP5 with R13 and D9, JP7, JP8, JP9, J1, JP13 and JP12. If you don't need the JTAG interface, you can leave out P2 and the connected resistors as well. Last thing you can leave out is the programming interface so P3 with associated resistors. You can replace OSC by an Xtal and two small capacitors. P1 is a big thing. You can replace it by a smaller connector p.e. a 6p6c modular jack. Last thing, you can replace the RS232 driver be a MAX3232 or similar. This type requires small 100nF capacitors instead of the

petrus bitbyter

Thank you all. I'm looking at the app. note and the AVR schematics. Although i'm not that familiar with hardware schematics, I'll see what i can do and will come back to you if i need further assistance.

thnx micro

download some application notes from atmel and copy the relavent portions of those circuits.

you might need a crystal (and a couple of capacitors) if the chips internal oscilator is unsuitable, you might need a voltage regulator if your supply isn't suitable raw, you might need some op-amps etc on the analog inputs (if the inputs have signals that are too weak), You might need a brown-out detector. you'll almost certainly need a supply decoupling capacitor - one is always reccomended.

best case no external components, worst case 20-30.

Bye. Jasen