| ??? 06/10/10 00:43 Read: times |
#176568 - Use 74HC595 to extend port Responding to: ???'s previous message |
Use 74HC595 to extend port
89S52 has 32 port dedicate P3.0(RX),P3.1(TX) other P3 for indicator , so use only P0,P1,P2(24 bits port) + 5 x 74HC595(40 bits port). Set simple protocol like ":N00" to on bit#00 ":N63" to on bit#63 and ":F00",":F63" to off bit#. I think RS232 is easier than multi drop of RS485. The project like this I did it before (192 bits port to control electricity of Hotel room) connect to PC via RS232 Pograming by VB also. |
| Topic | Author | Date |
| 89s52 communication with visual basic | 01/01/70 00:00 | |
| Double the fun.. | 01/01/70 00:00 | |
| RE: Cables & hubs | 01/01/70 00:00 | |
| use an 8-porter ... | 01/01/70 00:00 | |
| Use 74HC595 to extend port | 01/01/70 00:00 | |
| 74hc595 as extended port | 01/01/70 00:00 | |
Spent any time with the datasheet? | 01/01/70 00:00 |