| ??? 06/27/08 06:52 Read: times |
#156238 - Common cathode dot matrix display and 8051 |
I interfaced AT89c51 to 5x7 common cathode dot matrix led display (similar to c5570y ).
7 Rows driven by PNP SK100 transistors,base connected to 8051. collector---220 ohm---display row. 5 Columns to ULN2003A output and inputs of ULN2003A are connected to 8051 with pullups. col---uln---8051 I am able to display 5x7 font characters on it but I do get come columns glow even if they are not selected that too in random manner.This is due to the reflection of the led which is currently glowing or the time delay between two character is not enough.How to fix this prolonged glowing of led ? |
| Topic | Author | Date |
| Common cathode dot matrix display and 8051 | 01/01/70 00:00 | |
| Show us your code. | 01/01/70 00:00 | |
| I missed that | 01/01/70 00:00 | |
| Base resister to the PNP? | 01/01/70 00:00 | |
| Details | 01/01/70 00:00 | |
| Output voltage | 01/01/70 00:00 | |
| Video | 01/01/70 00:00 | |
| cause | 01/01/70 00:00 | |
| Easier Way To Do It (Design Experience) | 01/01/70 00:00 | |
| incorrect | 01/01/70 00:00 | |
| It's Correct | 01/01/70 00:00 | |
| nope it is NOT corect | 01/01/70 00:00 | |
| Read Again Please =) | 01/01/70 00:00 | |
that is contradictory | 01/01/70 00:00 |