ARM (or other 32 bit) MCUs in PDIP ?

Digikey is good for searches like that. You can go into embedded/microcontrollers, filter by ARM core, then look at the available DIP packages.

There aren't any.

Thanks for looking.

I didn't think of Digikey, but I did try other places, including manufacturer websites, and also came up empty.

It was just seeing the PIC32MX available in PDIP (and not knowing about it until now) made me wonder if anyone else was also doing 32 bit PDIP MCUs and I just had not come across them yet.

Simon.

I suppose Microchip and to a lesser extent Atmel are traditionally the more "hobbiest friendly" manufacturers.

Recently the others seem to be trying for this market too, perhaps realising that the hobbiests of today could be the product designers of tomorrow. But they are doing it with very low cost development boards (and free tools). Not as DIP packaged chips.

There's no (or very limited) industrial/commercial demand for new architectures in DIP form-factors and the miniscule hobby market isn't enough to support making them. Besides, a 40-pin DIP is pretty danged big already; imagine a 64- or 100-pin monster.

Your best bet is probably to look for the device already mounted in a header board with breakout pins. See, for example,

If you're more into roll your own, look for prototyping adapters that break-out the SMT processor's pins into accessible headers. Bellin makes a lot of these in various configurations

I don't know of any currently available one. NXP's LPC1114FN28/102 (Cortex-M0 in DIP28) is still in development, supposed to be out later this year. I have a vague memory of old Luminary having a DIP-packaged Cortex-M3, but if so it's been cancelled a long time ago.

-a

What I do is put the chip on a "breakout" board and put it next to my breadboard. It's rare to find interesting (to me) MCUs in DIP format these days. Example breakouts:

The RX is a 32-bit part, and the 62N has built-in host/device USB and ethernet MII.

a 16-bit MCU breakout specifically designed for breadboarding

DIP adapter for 16-bit R8C with host/device USB (the breakout only supports device as-is)

MCU with an FT232R interface, can use plug-ins or wire-to-breadboard (example use:

Has a photo with various dip-packaged MCU adapters

There are plenty of places online to have one-off or small-batch breakout/adapter PCBs made, if you don't mind soldering the chip to it. Solder once, then use it with your breadboard.

Now _that's_ the kind of device I am thinking of. :-)

Thank you. The Farnell pricing on the packaging variants which are currently available is very reasonable so I hope PDIP follows the same general pricing pattern when it becomes available.

It's a pity it doesn't have USB device, but there are still a number of things I can use this device for.

Thanks,

Simon.

Thanks for the interesting selection of links and ideas.

Thanks also to everyone else for breakout board suggestions.

For now, I would like to use continue using PDIP in my own circuits, but I agree with people here in that I think I am going to be forced into a breakout board type situation in the future as newer devices come along.

And you are quite correct; it would not be too difficult to have a series of generic breakout boards made once I make that move.

Thanks everyone,

Simon.

Hello Simon,

Please do not take this badly,

What is so wrong with coming into the 21st century ?

If you want to play with the big boys, you've got to learn what the big boys know.

With the number of devices within the soldering abilities of most beginners, using a 48 or 64pin tqfp will get you more and better devices.

Why is dip the only game you want to play ??

I would really like to know what keeps you in the 1980s ?

Thanks

don'

I won't; it's a fair question.

Because up until now, it's been sufficient for my projects.

As I mentioned in another post, I suspect I am going to have to move to using breakout boards in the future.

Simon.

I would also like to ask, why not use one of the breakout boards now? People often ask similar questions, and it generates a lot of answers, but without much feedback on what the "stopper" is. Is it cost? Complexity? Availability? Unfamiliarity? Cost of tools? I have no real idea, which makes it hard to tailor future suggestions.

One problem I see is that a lot of breakout boards are quad package, or dual row, which is not convenient for stripboards. Or they are DIP package, but have a lot of extras added, which bumps up the cost and forces you into specific design choices. I suspect what people really want, is just a chip on a DIP board, as cheaply as possible. There is little profit in that, and hundreds of possible chips, so it is unlikely to attract commercial interest. BatchPCB makes it really easy for people to order bare boards, so that is half the job. The other half is finding an enterprising amateur willing to provide a soldering service for a few $.

soldering

Or bite the bullet and learn to DIY. Once one has gotten past the scary place of a side by side comparison between a 0.1" DIP and 0.5 mm TQFP, it turns out that surface mount work is remarkably easy. The how-to videos over at Sparkfun and Dave's EEVBlog provide good demonstrations.

It's great that you find it remarkably easy, but did you stop to think that some people with failing eyesight and unsteady hands may have also tried it and found it remarkably difficult?

You ask a series of good questions. I will try and answer them in detail below.

Simply because the trade off with the issues I mention below versus the wide-ranging availability of PDIP parts means that (for projects for which PDIP parts are available) I prefer to use those PDIP parts.

For something which requires a ARM7 (and above) processor, I just buy a board from somewhere like Olimex.

I understand. Below is my current thinking on the questions you ask.

The breakout boards I see have a whole lot of extras added onto them which are of no interest to me and just bump up the price and size.

A number of them are also designed as standalone units instead of something which can be plugged into a stripboard/veroboard base unit. In that case, you have to work with what is on the board, instead of been able to build your own circuit around it.

Complexity is not a issue in that I can just ignore the parts of a board I don't need.

Availability is not really a issue; they tend to be freely available here in the UK.

When I get a idea for something, I like to be able to design something which contains just the components I need, and nothing else. There's also the fact that projects could involve more than one breakout board, which rapidly starts multiplying the price difference.

Therefore, this leaves the option which we have been discussing which is having some bare generic adapter templates made which, when populated, would contain nothing but the IC in question plus the 0.1 inch pitch pinouts.

The price of having custom boards made is not really too much of a issue for me. For designing them, I would just use gEDA and the cost of a batch of boards does not seem too bad (at least the last time I looked).

The real problem with this, and this is the core problem here, is working with components that small. I don't currently have the skill set required for that and I am not sure what extra equipment is required in case I need help soldering something that small in case my hands are not steady enough.

Cost of development tools for software development is not a problem. For the hardware side of things, I just use a low cost JTAG tool for the ARM boards (a Wiggler clone from Olimex) and I built a programmer for the AVRs which I use with AVRdude.

On the software side of things, both for AVR and ARM, I just use a open source toolchain (gcc/binutils and, for the ARM boards, OpenOCD/gdb/ddd).

I don't need any of the handholding stuff which you see in the commercial toolchains. I just write my own headers (using the datasheet) if they are not available or the manufacturer uses coding conventions I disagree with.

Likewise, on the ARM, I am now using my own startup code template, which I alter based on the manufacturer's documentation and any issues raised by the manufacturer supplied startup code (which I just view as documentation for things which should have been in the datasheet/reference manual but wasn't :-)).

Unfamiliarity isn't really a major problem in a number of cases, but it depends on the degree of unfamiliarity. Learning another ARM MCU isn't a problem. Learning a completely new architecture (ie: MIPS) requires a far larger amount of time to be available.

Assuming I had the time on a specific project, I would take the lack of familiarity as a opportunity to learn something new.

This is exactly the problem. I am quite capable of building my own circuits provided the parts are in a size I can work with. I am not interested in breakout boards that are loaded with a whole set of parts which bump up the size and price.

Thanks for the pointer.

BTW, when I finally go down this route, it will be me doing the soldering as I will regard it as another skill to be learnt. :-)

I hope this helps you understand the issues I consider and the priority I assign to each type of issue.

Simon.

Hi Simon,

If you search the archives for this group and perhaps sci.electronics.design and sparkfun you will see lots of advice/tutorials on soldering surface mount chips.

But basically the key ingredients are

- bright light

- magnification (e.g. headband magnifier)

- flux (which is in the solder but only lasts a few seconds)

I don't find steady hands to be an issue; you just rest them on the work surface,

h.

I seriously doubt you would have a problem soldering SMT boards, it is probably just a matter of being a bit daring the first time. You will discover it will cost you much *less* time and effort; put the solder paste on the board, place the parts then bake in a kitchen oven (I use a $100 2kW one, of those small ones, sort of microwave oven sized). Get an IR thermometer and you will be equipped well enough. Oh, and for rework you will need two soldering irons, that is how I do it at least. I also have a blower (hot air station, I believe), but I have been getting away without having one in the past. And I manage boards like this one more or less routinely:

Dimiter

------------------------------------------------------ Dimiter Popoff Transgalactic Instruments

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The large IC on that board looks like a BGA package. I've been avoiding BGA for home projects because I can't figure out how I would possibly troubleshoot and rework such a board with exotic stuff like an X-ray inspection machine, etc. Have you got experience with BGA on a budget?

Ed

SchmartBoard has a line of adapters. Easy to work with. Never had any issues ordering from them.

One feature of the Schmartboard is their "ez technology" which puts the SMT leads onto recessed pads, so they sort of "fall into place." Can't get much easier...