Re: Prototyping surface mount microcontrollers

On Tuesday, in article <132ahcla82pf0cd@xxxxxxxxxxxxxxxxxx>
grante@xxxxxxxx "Grant Edwards" wrote:

On 2007-04-17, Berk Birand <dont@xxxxxxxx> wrote:

Now my question is, how is prototyping performed on chips like
these, where you can't directly connect a breadboard? Do they
typically build the entire system as a PCB, get it printed and
then see if it works (going through the process again if it
doesn't)? Or are there any parts that could convert between
the two packaging, similar to the one above, except more
generic?

All of the above. Sometimes you just go ahead and layout a
board. Sometimes you buy an eval/demo board. You can also get
generic prototypeing boards for various SMT packages.

Other factors depend on if you have used that controller (family) before
as to whether you would use an eval/demo board or have some software to
start off with. You may also use eval/demo board or previous projects
to test the basics of hardware and software interfacing.

The main consideration is how many pins the conroller has, as breadboarding
something with especially over 40 pins, takes a long time and creates
a lot more possibilities of unreliability. Spending half of your time
finding why something does not work due to broken wires etc. is wasteful
of time.

Using transition boards to take SMT chips to wires or DIP style connections
even using boards like Schmart boards can help. but you still have the
potential for problems to bite you during development.

Whatever CAD package you use to make your own prototype board means that
when the first board has been made and tested you have a starting design
and layout that can be used to get fully working board. You generally
have moved some of the board development forward. Final board layout has
enough issues with position of external components and other isues, so
saving time can be useful.

A current job (no controller) had a few breadboards for a few large pin
count devices to test a few sections of the designs. However it currently
is on TWO PCBs as the amount of connections, connectors and everything else
meant it was the only way to get some form of reliability for putting the
lot together and testing it.

--
Paul Carpenter | paul@xxxxxxxxxxxxxxxxxxxxxxxxxxx
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.

Relevant Pages

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