| ??? 08/28/06 10:06 Read: times |
#123182 - Assuming that the external pullups are not working Responding to: ???'s previous message |
Assuming that the pullups are not working properly, I did this alteration
CONFIRM_KEY_PRESS: mov p0,#0f0h
acall delay_16ms MOV A,P0 ; p0.0 t0 p0.3 => rows, p0.4 to 0.6 => columns ANL A,#01110000b ; scan columns cjne a,#01110000b,KEY_PRESS_CONFIRMED ; if key pressed within 423ms, come out of delay loop DJNZ R2,CONFIRM_KEY_PRESS DJNZ R1,WAIT3 DJNZ R0,WAIT2 SJMP SECOND_KEY_SCAN1 ; if no key is pressed within 423ms, come out of key checking subroutine but the problem presists. |
| Topic | Author | Date |
| problem with delays | 01/01/70 00:00 | |
| Omitted pull-ups at Port 0? | 01/01/70 00:00 | |
| No, it's pulled high | 01/01/70 00:00 | |
| You should see the connection... | 01/01/70 00:00 | |
| could it be your approach? | 01/01/70 00:00 | |
| p0 initialised as input port | 01/01/70 00:00 | |
| post the WHOLE code | 01/01/70 00:00 | |
| WHOLE code | 01/01/70 00:00 | |
| Try this | 01/01/70 00:00 | |
| WHOLE code | 01/01/70 00:00 | |
| Assuming that the external pullups are not working | 01/01/70 00:00 | |
| why is the delay not being excecuted? | 01/01/70 00:00 | |
| HOW DO YOU KNOW | 01/01/70 00:00 | |
| Through debugging | 01/01/70 00:00 | |
| I know nothing about keil debugger | 01/01/70 00:00 | |
| make code that resembles the flowchart and you wil | 01/01/70 00:00 | |
| whole? | 01/01/70 00:00 | |
| Ashwins stack handling is totally unsuited! | 01/01/70 00:00 | |
| to generate tone of octave(8keys)with 89c51 | 01/01/70 00:00 | |
sandy please start a new thread | 01/01/70 00:00 |