On Fri, Mar 12, 2010 at 11:28 PM, vasile surducan <[email protected]>wrote:
> > > On Fri, Mar 12, 2010 at 7:21 PM, mattschinkel <[email protected]>wrote: > >> We have now updated The Tutorial Book to version 0.3 >> >> This book is available as a PDF file, you can download it from jallib >> project page: http://jallib.googlecode.com/files/Tutorial_Book_0.3.pdf >> >> > I've read it quite fast. It will become a good tutorial book, however there > are a few things which maybe you'll try to modify on next versions: > > 1. page 51, you refer to "plenty resources" and the link goes to google > search page for "i2c". It suppose a reader of this tutorial knows to search > on google using keywords, else he never find the tutorial itself... "this > page" is a very good resource, however maybe deserve a full name, so the > reader remember next time where is going. > 2. the unnamed figure (btw, any image, formula or table should have a name, > so you can refer at it in the tutorial text or talking about it on email) > from page 52 has a low resolution, try to use at least 300dpi when export > bitmap from eagle and convert it in grayscale, it's much better visible > 3. on page 53 two pictures repeat (they aren't numbered as well), in one of > them you point at some resistors without naming those resistors as R4 and R3 > (I've told you this last time too), on every schematic or image, being a > tutorial, the reader does not need to guess the component numbers or where > is pin 1 of the IC. > > There are more issues, but If you'll try to add at least numbers to the > figures and refer in text to the schematics and image numbers when > explaining something, will start looking as a tutorial. > > > Going further: 4. page 97 three irrelevant pictures on a whole page 5. page 98 table on the top of the page (please add a table number) is talking about V5 (which is known in literature as VS or contrast voltage) and on the "remark" colums it says variable which is correct but 6. on page 99 where is a schematic, the V5 becomes Vee (there is inconsistancy in table, schematics and probably in the book text). VS could be a -2.5...-5V output on many LCD, so you're telling to the beginner to kill his toy... VS should be connect in the worst circumstances with a resistor to ground. There are LCDs which need positive voltage around +2V on VS for a good contrast. The universal solution is a potmeter of 10-20K connected with wiper on the VS pin1 to +5V and pin3 to Vee (where Vee is a negative voltage). If LCD does need negative voltage, pin3 is connected to GND. See here a picture: http://webspace.webring.com/people/dv/vsurducan/electro/PIC/f877.html On your schematic is missing the reset capacitor from RA5 to GND and the 100nF near the PIC supply and another 100nF near the LCD supply. 7. picture from page 100 should go on page 99 8. picture from page 101and 102 seems irelevant to me Even Seb will be angry with me, the purpose of a good book is not filling it;s pages with huge pictures, when you're drinking a french cognac, you need a small quantity, but with the best taste ever... :) Vasile -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
