Which method would you use with A PIC UART & RS485 chip?

I've used the second method (without 10K resistor) in my schematics and as much as it works I wonder why no pullup or pulldown resistor is used when RE pin2 is pulled high. The datasheets indicate this floats the RO pin1 and I wonder how a PIC UARTs RX pin is affected?

I could simply ground the RE pin as in the top MAX483 (and maybe that's the right way)

Comments?

Take a look in the current issue of Everyday Practical Electronics. I've just done an article on RS485; that might help.

Mike.

Re: Which method would you use with A PIC UART & RS485 c

William At MyBlueRoom said:

Comments?

Click to expand...

I'm sorry that I don't have anything to answer your question about the serial chips, but I must say, that is a very nice looking technical diagram ... call-outs with drop shadows, and a big blue star in the corner!

what software are you using, is that Visio?

oh, btw, you have a typo!

It's a great little program called Snagit https://www.techsmith.com/

I also used it's printer capture for the PNGs of the schematics on my site.