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.

      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.
3/8/04 Xu, 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. Neil 3/7/02 Hi all, I met a problem yesterday. The problem was like: when I ran uisp commands, error message said:"the wire is incorrect or chip is damaged" 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. good luck! BTW, do we have a mailing list of all the guys in the class? I recommend to build one if there isn't. Xu