| ??? 02/05/05 08:18 Read: times |
#86611 - to much for all Responding to: ???'s previous message |
Hi Gondya
as i suspected yesterday you did not take care about the 80mA restriction with 270 ohm resistor you have about 15mA per portpin and if you light up 6 LED you already have 90mA that is not save. read datasheet especialy the the part with the 80mA for all outputs to understand what is going on. But you need solution for your problem. First is to use 390ohm resistors this will give 10mA per portpin so if all are on you get 80mA. But then the LED's are not so bright. Second is to use software to cheet our eyes. Switch the LED on and off at 100-120 Hz and turn always only the half of them on. So they seem to be on all at once but as you swith them the controller has to drive only 4 at once. Have fun Peter |
| Topic | Author | Date |
| required AT89c2051 help on leds | 01/01/70 00:00 | |
| P1.0 and P1.1 input only | 01/01/70 00:00 | |
| Ignore earlier post | 01/01/70 00:00 | |
| trying to understand | 01/01/70 00:00 | |
| oh, by the way re posting code | 01/01/70 00:00 | |
| Check the datasheet | 01/01/70 00:00 | |
| to much | 01/01/70 00:00 | |
| Circuit Details of Led's | 01/01/70 00:00 | |
| to much for all | 01/01/70 00:00 | |
| 3rd way | 01/01/70 00:00 | |
Solution works | 01/01/70 00:00 | |
| ASCII schematic of Peter Herbst solution | 01/01/70 00:00 |