Need to free up a pin with a hardware solution.

Archiver

When I send serial info to a RS485, I first have to set pin3 to the
RS485 high, before I start transmitting data.

I must try to make this signal without the use of the stamp.

So I need some type of programmable timer or logic gates to look for
serial inverted data, and then create the high signal to the RS485
as long as I transmit.

I fast and simple hold circuit that is trigged on the low signal
from the serial line and hold an output signal for 5 ms after the
last low signal, will do.

I could miss the first character, but this can be compensated in the
stamp.

I tried a resistor and cap, but it was not charging fast enough.

Any other solution out there?

Archiver

Hello