| ??? 03/19/05 00:29 Modified: 03/19/05 00:32 Read: times |
#89986 - Test it without having any communication Responding to: ???'s previous message |
Geert said:
I will do the check by only reading the PCF8574, that's a good idea (although I prevent the input pin from being written with a '0', see the answer I gave to Erik's remark above). To be totally clear, whether the strange performance is a hardware or software issue, test the port pin's potential with scope, without having any communication between micro and PCF8574, means neither writing nor reading the PCF8574. The idea behind is, that PCF8574's port pins are all configured as inputs immediately after power-on. And if the port pin's potential works properly without communication, then the mistake will have to do with your code very probably... Kai |
| Topic | Author | Date |
| Problems with PCF8574 input | 01/01/70 00:00 | |
| best guess | 01/01/70 00:00 | |
| To Erik | 01/01/70 00:00 | |
| So.... | 01/01/70 00:00 | |
| To Jez Smith | 01/01/70 00:00 | |
| show the code | 01/01/70 00:00 | |
| To Oleg | 01/01/70 00:00 | |
| How to post code | 01/01/70 00:00 | |
| To Andy | 01/01/70 00:00 | |
| hmmmmmm | 01/01/70 00:00 | |
| To Jez | 01/01/70 00:00 | |
| RTFDS - using 8574 IO as inputs | 01/01/70 00:00 | |
| To J. Guy | 01/01/70 00:00 | |
| When is pin written ? | 01/01/70 00:00 | |
| My datasheet tells something different.. | 01/01/70 00:00 | |
| To Kai | 01/01/70 00:00 | |
| cutting through the fog | 01/01/70 00:00 | |
| To J. Guy | 01/01/70 00:00 | |
| Where is the difference between... | 01/01/70 00:00 | |
| To Kai | 01/01/70 00:00 | |
| Re:Problems with PCF8574 input | 01/01/70 00:00 | |
| Test it without having any communication | 01/01/70 00:00 | |
| To Kai | 01/01/70 00:00 | |
| Maybe good guess! | 01/01/70 00:00 | |
| To Medhi | 01/01/70 00:00 | |
| Switch terminology | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| Coonfoosed yeeet | 01/01/70 00:00 | |
| Contact arrangement - nothing else | 01/01/70 00:00 | |
| PCF8574 | 01/01/70 00:00 | |
| To Ben | 01/01/70 00:00 | |
| I have used the bugger often | 01/01/70 00:00 | |
| To Erik | 01/01/70 00:00 | |
| helloooooooooo !! | 01/01/70 00:00 | |
| To Erik | 01/01/70 00:00 | |
| Wager... | 01/01/70 00:00 | |
| To Grant | 01/01/70 00:00 | |
| The code... | 01/01/70 00:00 | |
| Thats told 'em :-) | 01/01/70 00:00 | |
| Frightend... ;-) | 01/01/70 00:00 | |
| Formatting | 01/01/70 00:00 | |
| Format flavours. | 01/01/70 00:00 | |
| Insanity | 01/01/70 00:00 | |
| Malaysian Grand Prix... | 01/01/70 00:00 | |
| Some update!!! | 01/01/70 00:00 | |
| Let me comment.... | 01/01/70 00:00 | |
| "fancy" code | 01/01/70 00:00 | |
| I'll Suggest... | 01/01/70 00:00 | |
| Pointers and structures | 01/01/70 00:00 | |
| C assumes int | 01/01/70 00:00 | |
| Followed the advice of Michael Karas... | 01/01/70 00:00 | |
| Why not assembly using? | 01/01/70 00:00 | |
| Assembler code | 01/01/70 00:00 | |
| Well... | 01/01/70 00:00 | |
| int | 01/01/70 00:00 | |
| Check Maxint ? | 01/01/70 00:00 | |
| Maxint | 01/01/70 00:00 | |
| Murdered quote | 01/01/70 00:00 | |
| I2C code | 01/01/70 00:00 | |
| Keil webpage | 01/01/70 00:00 | |
| i2c simulator | 01/01/70 00:00 | |
| Me to blame? | 01/01/70 00:00 | |
| not blaming you! | 01/01/70 00:00 | |
| Michael B. made a very usefull tool! | 01/01/70 00:00 | |
| hello | 01/01/70 00:00 | |
| Not aware? | 01/01/70 00:00 | |
| thank u | 01/01/70 00:00 | |
Name confusion... | 01/01/70 00:00 | |
| hi | 01/01/70 00:00 | |
| Damned, damned, damned... | 01/01/70 00:00 | |
| Ha, ha, ha, ha, ha .... | 01/01/70 00:00 | |
| Calico | 01/01/70 00:00 | |
| Pls. do so! | 01/01/70 00:00 | |
| Keyboard Calico | 01/01/70 00:00 | |
| Christmas | 01/01/70 00:00 | |
| Maybe it was .... | 01/01/70 00:00 | |
| Christmas Presents | 01/01/70 00:00 |