| ??? 12/16/07 15:04 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#148333 - Wrong way up! Responding to: ???'s previous message |
Siddharth Dad said:
anode of the LED to the port and cathode to GND thru 330 ohm resistance That'll be the wrong way up, then! An 8051's port drivers are basically Open-Drain - so they can sink current, but not source it. For details, look in the Datasheet, and/or the so-called "bible" for the 8051 (Chapter 3, p2 on): Chapter 1 - 80C51 Family Architecture: http://www.nxp.com/acrobat_d...ARCH_1.pdf Chapter 2 - 80C51 Family Programmer's Guide and Instruction Set: http://www.nxp.com/acrobat_d...UIDE_1.pdf Chapter 3 - 80C51 Family Hardware Description: http://www.nxp.com/acrobat_d...WARE_1.pdf |
| Topic | Author | Date |
| problem in blinking LED | 01/01/70 00:00 | |
| use a transistor to drive your LED | 01/01/70 00:00 | |
| How did you connect the LED? | 01/01/70 00:00 | |
| RE: How did you connect the LED? | 01/01/70 00:00 | |
| and where goes the other end? | 01/01/70 00:00 | |
| RE: and where goes the other end? | 01/01/70 00:00 | |
| Wrong way up! | 01/01/70 00:00 | |
| the other way around | 01/01/70 00:00 | |
| check anode/cathode of led | 01/01/70 00:00 | |
| What LED? | 01/01/70 00:00 | |
| The LED is a factor! | 01/01/70 00:00 | |
| Built-in resistors? | 01/01/70 00:00 | |
| changing the polarity helps | 01/01/70 00:00 | |
| Need more detail | 01/01/70 00:00 | |
| Help others | 01/01/70 00:00 | |
| solution tht worked | 01/01/70 00:00 | |
| neve drive led directly with an 8051 , always | 01/01/70 00:00 | |
Wrong - there's nothing wrong with direct drive... | 01/01/70 00:00 | |
| Well done | 01/01/70 00:00 |