| ??? 03/31/09 08:30 Read: times |
#164041 - Port pin as an input Responding to: ???'s previous message |
Hi all,
Despite your help and advice I am getting more and more confused! What is wrong in the following?: - First of all if I say "P2_0 = 1", that should set the pin to high level, correct or not? If after that, nothing beeing connected to P2.0 if I say "if P2_0 == 1" that should be true, correct or not? - Now if the pin P2.0 is connected to 0V then doing "if(P2_0 == 0)" should be true, correct or not? I can check that it works pulling down the voltage with a wire, I can check that the HCT (not connected) can drives its output at low level, BUT when both the 89C450 and the HCT are connected there is no way to pull down the input line. Sorry to bother you with this problem that must be so evident that I can not find the solution by myself. Michel |
| Topic | Author | Date |
| Pulling to 0 | 01/01/70 00:00 | |
| chips | 01/01/70 00:00 | |
| 89C450 | 01/01/70 00:00 | |
| Set a pin as input | 01/01/70 00:00 | |
| Port pin as an input | 01/01/70 00:00 | |
| Put load on HCT output | 01/01/70 00:00 | |
| Checking | 01/01/70 00:00 | |
| I see what you want to do there ... but ... | 01/01/70 00:00 | |
| so check 74hc165 with resistive load only | 01/01/70 00:00 | |
| It's not uncommon... | 01/01/70 00:00 | |
| I know that some use antiques, but ... | 01/01/70 00:00 | |
| Do we mean the same? | 01/01/70 00:00 | |
| I asid 'modern', not Arghmel | 01/01/70 00:00 | |
| Come on, Erik.... | 01/01/70 00:00 | |
| now let me get this straight ... | 01/01/70 00:00 | |
| one thing I always do ... | 01/01/70 00:00 | |
| Shame on me! | 01/01/70 00:00 | |
| Oops! | 01/01/70 00:00 | |
| Been there, done that | 01/01/70 00:00 | |
IO expansion | 01/01/70 00:00 |