| ??? 01/23/06 17:21 Read: times |
#108108 - circular buffer Responding to: ???'s previous message |
Second technique.
1. Make array of 54 bytes. Make three pointers: Base Refresh Pointer - BRPTR, Load pointer - LPTR and Work Refresh Pointer - WRPTR. 2. Clear the array at initialization. Set BRPTR and LPTR to the begining of the array. --- Refresh --- 3. Load WRPTR from BRPTR. 4. Any time reftersh interrupt comes take data from WRPTR, shift data to LCD then increase WRPTR. If WRPTR goes over of the array then set in to the beginning. Do it for all 48 columns then go to 3. --- Scroll --- 5. If you need to scroll: just increase BRPTR. If BRPTR goes over of the array then set in to the beginning. 6. Each six scroll load new character from EEPROM, translate it via bitmap table and put 6 bytes of result to memory pointed by LPTR. Then load LPTR from BRPTR. 7. If the character is End of String then re-initialize EEPROM for reading string from start. No moving, no pain. Regards, Oleg |
| Topic | Author | Date |
| Very long message multiplexing | 01/01/70 00:00 | |
| Speed? | 01/01/70 00:00 | |
| does not matter | 01/01/70 00:00 | |
| How Many Chars on Display? | 01/01/70 00:00 | |
| To Ian | 01/01/70 00:00 | |
| Hardware? | 01/01/70 00:00 | |
| Hardware,Ian | 01/01/70 00:00 | |
| Hardware | 01/01/70 00:00 | |
| When erik and oleg can spare time? | 01/01/70 00:00 | |
| Such impudence! | 01/01/70 00:00 | |
| exactly | 01/01/70 00:00 | |
| a circular buffer does not require data | 01/01/70 00:00 | |
indeed but | 01/01/70 00:00 | |
| circular buffer | 01/01/70 00:00 | |
| Really Dan I said experienced.. | 01/01/70 00:00 | |
| Are you the 1st one? | 01/01/70 00:00 | |
| by the way I have no experienceI | 01/01/70 00:00 |