| ??? 03/01/06 15:01 Read: times |
#110976 - Picogate 74HC1G125 Responding to: ???'s previous message |
I'm just using a picogate tristate buffer, which you can get in a tiny SOT23-5 package. The tristate control is connected to a programmable output bit and it is enabled when the micro has ownership of the bus. In my protocol the master drives any time it likes, for a slave it is the 100msec window after it has received a command.
The comms wire goes direct to the receive inputs, which means that a transmitter will see its own transmission echoed immediately, and I'm going to deal with that in firmware. I could put an AND gate between the line and the receiver to blank out the echo, but it doesn't seem worth it. My application doesn't go over long distances so the relatively poor noise immunity of TTL signal levels shouldn't be a problem. |
| Topic | Author | Date |
| rs232 bi dirctiontional in 1 wire | 01/01/70 00:00 | |
| 1 wire | 01/01/70 00:00 | |
| Dalla 1-Wire (TM) | 01/01/70 00:00 | |
| 1Wire | 01/01/70 00:00 | |
| Not RS232 | 01/01/70 00:00 | |
| Half-duplex | 01/01/70 00:00 | |
| As per Andy Neil | 01/01/70 00:00 | |
| tristate buffer? | 01/01/70 00:00 | |
| Picogate 74HC1G125 | 01/01/70 00:00 | |
| Tristate? | 01/01/70 00:00 | |
Special requirements | 01/01/70 00:00 | |
| Multiprocessor Comms | 01/01/70 00:00 |