| ??? 04/03/10 03:41 Read: times |
#174796 - Normally very weak source Responding to: ???'s previous message |
Note that most 8051 chips can only sink current. They have very weak pull-up resistors to hold the pins high.
That means that with a traditional 8051 chip, you can't just switch between sinking and sourcing current to LEDs. If you really do need to source current, you'll have to check the datasheet and get a 8051 variant that can reconfigure the I/O pins for full push-pull. |
| Topic | Author | Date |
| New with MCUs need a little help. | 01/01/70 00:00 | |
| Hi | 01/01/70 00:00 | |
| Some answers but now concerns | 01/01/70 00:00 | |
| Normally very weak source | 01/01/70 00:00 | |
| Can't find that detail | 01/01/70 00:00 | |
| Not many 805x's have push-pull outputs. | 01/01/70 00:00 | |
| Reset | 01/01/70 00:00 | |
| SDCC | 01/01/70 00:00 | |
| Books | 01/01/70 00:00 | |
| Electronics | 01/01/70 00:00 | |
| first read "the bible" | 01/01/70 00:00 | |
| Maybe not First? | 01/01/70 00:00 | |
| Rickey? | 01/01/70 00:00 | |
| I am new, Just somthing I wanted to do. | 01/01/70 00:00 | |
| Dead links | 01/01/70 00:00 | |
| No you are right | 01/01/70 00:00 | |
| hrm | 01/01/70 00:00 | |
| Argh!!! | 01/01/70 00:00 | |
| It's a highly dynamical thing... | 01/01/70 00:00 | |
| a reset writeup, but you don't want to read it now | 01/01/70 00:00 | |
| You mean this one? | 01/01/70 00:00 | |
Thanks | 01/01/70 00:00 | |
| not dead, just incorrectly copied | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 |