| ??? 07/01/08 03:43 Read: times |
#156331 - Easier Way To Do It (Design Experience) Responding to: ???'s previous message |
Hi, I worked on redesigning an obsolete design using exactly that type of LED matrix display.
You don't have to control the row and the columns, only the columns but rapidly alternate which row is being displayed. For almost any number of LED matrices, you can simply: 1. Send out a n-bit serial stream of data, length based on number of LEDs in a row. Pins required: 1 Each bit turns on a given column in the matrix. 2. Then turn on a transistor supplying +V to all columns in a row, across your LED sign, common anode. Pins required: 7 pins, if 5x7 (7 rows to turn on) 3. Keep the row on for a period of time, then turn off and move to the next row, and repeat process. 4. +control lines for a given LED driver IC, or none if not used! All you really have to do it ensure you keep a given row on for a sufficient period of time to avoid flicker. Alternating rows keep the power requirement low. Just an idea or two! But I recommend avoiding using hard to find LED driver ICs...had lots of problems from getting them later..! :) |
| 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 |