| ??? 09/09/05 08:14 Read: times |
#100843 - 8051 port problem Responding to: ???'s previous message |
Connect a LED in series with a resistor(2.2 to 4.7K) from port pin
to Vcc.Led will be off when port-pin value=1 and on when port-pin value=0. You must not ask more than 1-1.5 mA from a port pin(when it is in 0 state)and 80nA in 1 state. If you want more current you have to use a NPN transistor(+ 4.7k pull-up resistor + 2.2k base resistor)or an IC(ULN2003). In this case Led will be on when port-pin value=1 and off when port-pin value=0. |
| Topic | Author | Date |
| 8051 port problem | 01/01/70 00:00 | |
| Which port? | 01/01/70 00:00 | |
| Port current | 01/01/70 00:00 | |
| 8051 port problem | 01/01/70 00:00 | |
| Just look at this: | 01/01/70 00:00 | |
| NPN? | 01/01/70 00:00 | |
| schmitt trigger | 01/01/70 00:00 | |
I guess you are referring to the hex | 01/01/70 00:00 | |
| Have you tried BLINK? | 01/01/70 00:00 | |
| checked the MCBx51 board | 01/01/70 00:00 | |
| Connect as shown | 01/01/70 00:00 | |
| Led problem | 01/01/70 00:00 |