need help to write code for 8051

Hello pdi,
writing after a long time. I was busy so i couldn't find time to write or study the code send by you. It is working all right with a KBD and LCD. One thing i should know shall i have to add another table for LED Matrix? How you have written the scan code tables please help me to understand. It is really difficult on my part to follow the logic. i am sorry, it is going very slowly due to me only. Please guide me.
thanks all
sks

hi sks,
the scan code tables are the standard ones for the AT keyboard which are outputted when the corresponding keys are pressed/released. When the key is released, the code transmitted by the keyboard is usually ( for the standard character set) 0f0h followed by the scan code. The code merely checks the code received after the 0f0h is received and using the scan code table fetches the corresponding alphabet/number.

and yes, u will need to make a look up table to display the alpha numeric characters on the dot matrix much similar to fetching the segment data when using a 7 segment data.
:-)

Hi pdi,
I don't understand the conversion part of the code.
"movc A,@A+DPTR" means loading the data in Accu one by one from the Data table am i right? From where you got these values "DB00h,0F9H,00h,0F5H,0F3H etc" up to "q", what does it mean are these values are for other keys? Am i asking a silly question?
Thanks all
sks

no, the question is not silly but perfectly valid :-). actually, apart from the standard character set, the table also contains some special key scan cods like the function keys F0-F10 on the keyboard which do not have any equivalent ASCII (or visual) representation, so these keys when decoded after fetching their scan code on release should be assigned some 'value'. so the 0f0h,0f1h ,...etc values were assigned to them just for easy reference in future.
Further, the table maps all the scan codes from 0 to 7fh whereas some scan codes do not do not map to any key on the keyboard, so those locations are entered as 00h.
So, if u want to write some code on say F0 key pressed, just compare the decoded scan code value to 0f0h and write some code if the compare matches.

:-)

Hi all,
Can any one help me by giving address of an INDIAN firm dealing with small brush less micro motor. The motor body diameter should be 5mm to 7mm, length of motor is not a problem.
sks

are you looking for a small motor as we have in our mobile phones?

No Mr Ajay,
It's Brush less Motor diameter should be 5mm to 7mm.
sks

Hello PDI,
After a long time, i am here again. missed all a lot. what about the solenoids
for braille project?
how are you all?
thanks
sks

Hi SKS,

Nice to see you back may old people on forum are missing

Hello Mr Ajay,
Thanks for reply. I was too busy and out of my town for a year, missed all of you a lot. could not finish that braille project due to the mechanical component.
Now i need your help to develop a PC Interface multi line information display board using LED Matrix. I think i will get your support and help.
Thanks
sks