3/10/04 Xu Sun
Trouble Shooting----how to build your own library
I have a question of last assignment---microcontroller. That's how to
build my own library in eagle. Raffi taught me how to do that this
afternoon. So I just posted the steps here, which will be helpful
when you want to use other chips on your board.
At http://fab.cba.mit.edu/classes/961.04/notes.html I put in a file for
news and notes that can be edited with site.py. Please use that instead
of a mailing list -- that way there will be a log of the discussion.
I met a problem yesterday. The problem was like: when I ran uisp
commands, error message said:"the wire is incorrect or chip is
Thanks for Manu's help. I've solved it. If you have the same
problem, you can handle it easily by running "python rx.py" before
running uisp commands.
If this doesn't work, try to measure the voltage between GND pin
and DTR pin of serial connector by multimeter that's on the bench.
You can find these two pins on Neil's schematic. The right voltage
should be like 11V then this voltage is input to regulator. The
output voltage from regulator is the supply voltage of Tiny15L which
should be powered from 2.7--5.5V. So make sure the voltage between
the VCC pin and GND pin of 15L is in this range.
BTW, do we have a mailing list of all the guys in the class? I
recommend to build one if there isn't.
if you can find out any schematics provided by the
manufacturer, your life will be much easier. However, the life is not
always that good. The following steps help you out if you are a
little bit unlucky this time.
1. Find out the sizes of the package you want to use,
usually you can find them in datasheet.
2. Draw the package with exactly right width, length,
right pins and clearance between pins... all that kinds of stuff. Be
very careful or real chip will not fit on your board. You can do that
yourself if you are really talent in drawing and have a plenty of
time, otherwise an easier way is to find out an existing package
similar enough to your desired one. Usually you can find them in
eagle library "smd-ipc.lbr". For example, your chip package is
something like SO14 with 14-pin, 5mm width.
3. open the package of SO14 in library "smd-ipc.lbr". Cut
it and paste it in a new library "package" you want to creat.
4. open "schematics" of new library, then draw something
rectangle and looking nice. then put on 14 pins. Click "name" on the
left pannel, and name all the pins such as Vcc, Gnd, Input etc
according to the datasheet.
5. open "device" of new library. Firstly instantiate your
schematics, the button is on the left pannel. And then press "new" on
your right hand side pannel, choose the package you just created. Now
you need to "connect" the pins in schematics with those in packages.
After this mapping is done, congratulations your library has been
built! don't forget to save your work.
6. "file->new" a schematic. in "library->use" enjoy using
your own library.