dc motor control with 89s52

thanks alot ajay
how can i control PWM with keyboard? e.g: i want to accalerate motor when i push 'button A' or reduce speed when push 'Button B' ....

all you need to do is change the value loaded in R7..
lets say if more the value of R7 more is speed then...
when you press A increment R7 and when you press B decrement R7..
so automatically the speed will also change..

i think i understand what you mean but i havent find how i apply it in assembler yet? can you please give the code i mean i dont understand how the program recieve "button a" from keybord?? thanks alot

i told you.. no need to use a keyboard.. just use 4 keys.. increase, decrease, stop, start... like that.. easy for u..

but i want to use keybord lo learn:D:D:D

then take a look at the keypad tutorial.. you will get good introductory stuff.. and sample codes..

its keypad i said keybord it is different i think:S and to communicate i must configure uart? am i write?

my mistake... check 8051 library and codes in download area.. you will get sample code for keyboard.. keyboard does not work on UART.. it has its own protocol.
thats why i was saying if you are new to programming then it will be good to use simple keys. But you are interested in Keyboard so use it.. will help you..

hi ajay! i need your help again. I write the program and i can start and stop the dc motor but i havent make the speed up or down.
I trying to explain the code and wait your helping:D
i create a file named DT and i gave it #125 to increment and decrement. When user push a button(speed up buton) in KEYBORD inc DT and setup this value timer1. And i try to do it with interrupt. when user pust the button inc or decrement DT and controling speed.
yes i wish you understand it :D:D please help...

i told you in my previous posts.. that change the value of R7 thats all...
may i see your code what you did till now