Great lecture. Thank you !!! I added 2 -7 Segment displays and multiplexing, for the keypad data entry. I will add 4 more multiplexed 7 segment displays that increment after ever second key pressed. This lecture was enlightening and at the same time fun. Thank you again !!!
Can we use AND logic to detect column after row detection instead of rotation logic.......like AND with 0Eh for column 0 AND with 0Dh for column 1 AND with 0Bh for column 2 AND with 07h for column 3
Why use two separate ports to scan the keypad. As you only need 8 pins to scan the 4 rows and 4 columns? Can you use a single port to do this? To save a full port for other devices?
I was able to combine both the Rows and Columns on to port P1. I put Columns on P1.0 - P1.3 So that we could continue to AND with 0Fh and I moved the Rows to P1.4 - P1.7 I started the program with mov P1, #0f0h to clear just the 4 Row bits. The only other changes I had to make was under CheckRow. Instead of Mov P1, 11111110B to clear the first Row bit, I changed it to Mov P1, 11101111B and I made sure to clear the correct bit for the remaining Rows as well.
@@StudyMicrocontrollers My question is, why is A necessary if dptr carries the correct pointer. Adding A seemed unnecessary. I was also wondering if I missed the Delay subroutine that was called under K2: I did enjoy the video, I do not use RRC or ANL, but it was very helpful to see them being used so eloquently.
Great lecture. Thank you !!! I added 2 -7 Segment displays and multiplexing, for the keypad data entry. I will add 4 more multiplexed 7 segment displays that increment after ever second key pressed. This lecture was enlightening and at the same time fun. Thank you again !!!
thanks so much, after searching for so long , i finally understood it
Fantastic lecture. Can clear each and every concept. Thanks a lot.
Its clear every doubt about keyboard inferfacing thanku very much
You are welcome
Thank u
MashAllah beautiful explanation
Thanks and welcome
Great lecture
THANKS MAM
Thank you.
Very clear explanation madam
Thankyou mam
Can we use AND logic to detect column after row detection instead of rotation logic.......like AND with 0Eh for column 0
AND with 0Dh for column 1
AND with 0Bh for column 2
AND with 07h for column 3
AND with 01h ,02h,04h,08h for column 0,1,2,3 respectively
Thanks a lot ma'am
Why use two separate ports to scan the keypad. As you only need 8 pins to scan the 4 rows and 4 columns? Can you use a single port to do this?
To save a full port for other devices?
I was able to combine both the Rows and Columns on to port P1. I put Columns on P1.0 - P1.3 So that we could continue to AND with 0Fh and I moved the Rows to P1.4 - P1.7 I started the program with mov P1, #0f0h to clear just the 4 Row bits.
The only other changes I had to make was under CheckRow. Instead of Mov P1, 11111110B to clear the first Row bit, I changed it to Mov P1, 11101111B and I made sure to clear the correct bit for the remaining Rows as well.
The MATCH: subroutine seemed a little strange to me. If you clr A, then you will always being adding 0 to movc a, @a+dptr ???
A is 0 but DPTR carries address of memory. Watch video of indirect addressing mode
@@StudyMicrocontrollers My question is, why is A necessary if dptr carries the correct pointer. Adding A seemed unnecessary. I was also wondering if I missed the Delay subroutine that was called under K2: I did enjoy the video, I do not use RRC or ANL, but it was very helpful to see them being used so eloquently.
@@StudyMicrocontrollers DPTR is incremented under FIND: So A needs to be clear. Thank you
Sir how to interface through 8255 ppi
Thanks ma'am
Most welcome 😊
help me help me