| ??? 05/29/05 07:42 Read: times |
#94082 - Yes, I do have quite a few ducks... Responding to: ???'s previous message |
Michael Karas said:
If the pins on the part you have chosen to connect the opto-coupler to are substantially similar to those on a bog standard 8051 then the comments I made regarding the use of the pullup resistors apply.
Besides all that.....resistors are cheap!! You can after all get the equivalent of about four 0402 sized resistors in a 1206 package, so board realestate should not be an argument!! Michael Karas Hi Michael, some 5 ducks are running around in my guarden and they indeed walk like they quack... ;-) As Ijaz also already stated: indeed, I have to see the PCF8574 port behaviour the same as the 8051 port behaviour wrt input. So, I will definitely follow your advice, since it has additional benefits, like shorter rise times and more defined behaviour. PCB space etc. is not at all an issue for me. I will have plenty. I will anyhow not use SMD components, 'old fashioned components' will/have to do the job. Thanks again for your useful advice, Best rgds, --Geert |
| Topic | Author | Date |
| CNX83: application examples? | 01/01/70 00:00 | |
| HOW | 01/01/70 00:00 | |
| did you find some in a drawer | 01/01/70 00:00 | |
| I know they're quite old... | 01/01/70 00:00 | |
| Better | 01/01/70 00:00 | |
| Schmitt Trigger | 01/01/70 00:00 | |
| nothing wrong - but | 01/01/70 00:00 | |
| Not working, Erik | 01/01/70 00:00 | |
| Pullup Or Not | 01/01/70 00:00 | |
| Additional Comment on Rise Time | 01/01/70 00:00 | |
| Confustion maybe? | 01/01/70 00:00 | |
| Yes, you need on PCF8574 | 01/01/70 00:00 | |
| No hijacking at all!!! ;-) | 01/01/70 00:00 | |
| Walks like a duck? Quacks like a duck? | 01/01/70 00:00 | |
| Yes, I do have quite a few ducks... | 01/01/70 00:00 | |
| Correct? | 01/01/70 00:00 | |
| Correct !! | 01/01/70 00:00 | |
| you must have edited | 01/01/70 00:00 | |
| I didn't do anything... | 01/01/70 00:00 | |
I do not know | 01/01/70 00:00 |