| ??? 04/19/11 06:17 Read: times Msg Score: -1 -1 Answer is Wrong |
#181944 - 89C55 connection with 2803 Responding to: ???'s previous message |
The ports Atmel 89CXX microprocessor, unlike the 80C31 or 80C51 should always be buffered as input or output, for instance with 74HC244 or 74HC245, with OE enable. 74HC245 is preffered with all inputs/outputs at any side we want. Dont forget to set the Direction control pin accordingly.
My suggestion is, try inserting 74HC245 between 89CXX and your 74HC595 which I have experience. Good Luck. |
| Topic | Author | Date |
| AT89c55 Connection with ULN2803/4 | 01/01/70 00:00 | |
| There is a FAQ for that | 01/01/70 00:00 | |
| MAX1232 + some NORs | 01/01/70 00:00 | |
| #181903 - AT89c55 Connection with ULN2803/4 | 01/01/70 00:00 | |
| '595 Chip /OE | 01/01/70 00:00 | |
| Pull-downs... | 01/01/70 00:00 | |
| 89C55 connection with 2803 | 01/01/70 00:00 | |
| Why? | 01/01/70 00:00 | |
| Why is Atmel different? | 01/01/70 00:00 | |
| Why 89CXX is different | 01/01/70 00:00 | |
| Advice not understood | 01/01/70 00:00 | |
| You didn't answer the question! | 01/01/70 00:00 | |
| Answer | 01/01/70 00:00 | |
not necessarily because of AT89 | 01/01/70 00:00 |