Removing ATmega

Does anyone know how to remove the ATmega328 from the Arduino? If I try to lift it up with my fingers from the ends, it seems stuk in pretty well. How can I remove it from the DIP IC socket?

Thanks! baum

Use an IC removal tool.

http://www.aboveboardelectronics.com/thomasandbetts/pdf/au_sockets/tools_dipw2.pdf

Failing that, gently lift each end a little at a time with a small screwdriver. Don't wedge it against other components.

OK. I'll pick up an IC puller. And to get it back in, I can just pop it in?

Yes. May need to squeeze the pins a little. Be careful, make sure they are all started a little before pushing it all the way in. Especially new parts, the legs are like spring loaded, you need to lay the part on its side and bend them all in some, but starting close to the body, not just the thin bottom part of the legs.

CrossRoads: Yes. May need to squeeze the pins a little. Be careful, make sure they are all started a little before pushing it all the way in. Especially new parts, the legs are like spring loaded, you need to lay the part on its side and bend them all in some, but starting close to the body, not just the thin bottom part of the legs.

I want to add that this takes a little bit of practice - it is very easy to "screw up" and mangle the pins; you might want to practice on some "throwaway" DIP ICs first.

Something else: DIP ICs and sockets are not made to be cycled in this manner (the pins will get weak and stop bending properly, or the contacts in the socket will lose their springiness; either way, loss of connection or intermittents can crop up, pins bent, etc); if this is something you intend to do often, you might want to look into using a 28-pin ZIF (zero-insertion force) socket instead of the regular DIP IC socket on the Arduino. Some of these sockets can fit right into the socket on the Arduino, some can't (some are too big and won't fit, or they have too short of "legs" to fit in the socket, or other issues). It is possible to build a shield or other adaptor to fit a ZIF socket onto a regular Arduino (you could even take it "off board" like CrossRoads - IIRC - did with his 644 "Arduino" hack - by using a 28-pin IDC connector on a ribbon cable to the off-board socket).

:)

Just checked out SFE's ZIF, in the comments people mentioned that it fit into the DIP socket on the board... so I'll get an IC puller from amazon and put in a zif socket.

Another question:

Let's assume I had an Uno SMD. How could I program standalone chips without messing up the SMD one on the board?

Thanks! baum

How could I program standalone chips without messing up the SMD one on the board?

This is one way (search for "Circuit (targeting an AVR on a breadboard)")... http://arduino.cc/en/Tutorial/ArduinoISP

But assume I already burned the bootloader. Can I write programs to the standalone ATmega without removing the main one?

baum: Just checked out SFE's ZIF, in the comments people mentioned that it fit into the DIP socket on the board... so I'll get an IC puller from amazon and put in a zif socket.

Another question:

Let's assume I had an Uno SMD. How could I program standalone chips without messing up the SMD one on the board?

Thanks! baum

Basically - in answer to both questions, you should bring out the ISP/ICSP pins to a standard 5/6 pin header (on your standalone), and use an ISP AVR programmer (which you can turn an Arduino into via a sketch in the examples, btw) to program the 328. This is basically how you install the bootloader onto the Arduino. In fact, by using an external programmer, you will gain 2K of flash space for your program (although, IIRC on the UNO, it has an optimized bootloader that fits inside 512 bytes - so you would only gain that much extra space on the UNO). The only reason the Arduino isn't this way to begin with is because the bootloader makes it easier for beginners to get started (and at the time, you needed to use a "real" AVR ISP programmer - which costs extra).

In fact - you might want to just build a standalone ZIF socketed "Arduino" on a "stripboard", bring out the ISP/ICSP pins to a header, then use your Arduino as the programmer as referenced above. That would probably be the simplest solution...

:)

OK. I'll do that. It will be easiest, as I need to write some code to a tiny2313, also.

Thanks! baum

Pry it VERY gently with a screwdriver on each side. Do it slowly.

When I do that, I hear tiny bits scratching off the casing... No, thank you.

baum: When I do that, I hear tiny bits scratching off the casing... No, thank you.

Yeah it tends to scratch it a bit :astonished: But just don't put in as tight next time.

put in as tight next time.

Tell that to the Italians who assembled the board. I haven't removed it yet. :)

Do you think an IC puller is worth it? I can get one for ~$5 from amazon.

baum:

put in as tight next time.

Do you think an IC puller is worth it? I can get one for ~$5 from amazon.

Those inexpensive ones don't look to me like they'd be an improvement over prying with a very small screwdriver. I use a screwdriver that's not quite as small as one that might be used on eyeglasses; the blade is very thin. Not a real fast process, but I've never had a problem or damaged a chip.

But I'd like to hear from someone who has used one of those inexpensive extractors. I suppose for $5 or so a person couldn't go too far wrong.

I use mine when I can find it. Otherwise I use a screw driver, loosening a little from each end. Not so much prying straight up as using a wider blade and more of slight rotation back and forth, loosen the pins on the left, then the right, then do the same on the other end of the board.

The machine that assembles them squeezes the pins together so they spring back against the socket when released.

Will have to give one a try. Seems I also once saw a tool to form the pins on a new DIP package parallel to better fit into a socket or circuit board. That'd beat my typical press-it-against-the-benchtop approach XD

I use a screwdriver that's not quite as small as one that might be used on eyeglasses

I'll try that with some jeweler's screwdrivers.

I realized after writing

I hear tiny bits scratching off the casing... No, thank you.

that the die itself is in the center of the chip, so no problems should arise.

Thanks! baum

I looked around and did not see any 28 pin 0.3" wide DIP insertion tools. Only less pin-count models, and 0.6" wide tools.

Am sure one exists, I haven't found it. Looks like squeezing on the work bench some more ...

Your answer is here https://youtu.be/sq66Lrx3dmg