| ??? 04/27/07 21:57 Read: times |
#138150 - If its for ISP Responding to: ???'s previous message |
If you want the RS232 for ISP, the transmit side ofthe circuit is simple, the receive side is where you have two signals that conflict. You can use an 'and' gate to combine the two receive signals - something like a 74HC08. In my boards, rather than use RS232 just for the download, I have a header that has the logic level signals connected to it and a 1k resistor in series with the receive signal from the 485 transceiver, that way my ISP programmer hardware can override the receive signal. |
| Topic | Author | Date |
| rs232/rs465 communication | 01/01/70 00:00 | |
| re:rs-232 and rs-485 | 01/01/70 00:00 | |
| rs-232 and rs-485 | 01/01/70 00:00 | |
| with an AND, not if it is properly biased | 01/01/70 00:00 | |
| one more suggestion | 01/01/70 00:00 | |
I think it is a lot 'cleaner' to add an inverter | 01/01/70 00:00 | |
| If it's just for programming... | 01/01/70 00:00 | |
| won't do (in the cases I know of) | 01/01/70 00:00 | |
| NXP | 01/01/70 00:00 | |
| If its for ISP | 01/01/70 00:00 | |
| RS-485 programming | 01/01/70 00:00 |