i am doing a max232 circuit and would like led indicators on both the pic side of the chip and pc side, pic side easy i will just use npn high base resistor as i only want a led indicator not a floodlight! and can do the calcs now but the prblem is while i know the pic side is 5V and have a rough idea of Vf for the Led i am unsure on the pc side, reading the maxim datasheet on there normal use circuit it shows a 10V + and 10V- from the charge pump (page 14 i think) anyway my question is. Is the output from the max232 pc side 12V or 10V? yes i could connect it up on bread board etc but i am doing a schematic so i can lay a board out, i know it dosnt really matter for a led but i would like to know if i calculate 12V-Vf or 10V-Vf, also reading the standards for rs232 it say's 12V and -12V so not sure what the actual voltage out the chip is. i could of course just use 2 leds on the RX and TX pic side but would be nicer to have RX TX on pc side as well.
also my bonus question is, are any of the other 9 pin connections on the Dsub from the pc at a voltage all the time? thats just because it would be nice to be able to tell if the cable was connected by sensing a voltage, not essential but i do like the bells and whistles and the little things make a difference lol (thats a mum quote)
LG
also my bonus question is, are any of the other 9 pin connections on the Dsub from the pc at a voltage all the time? thats just because it would be nice to be able to tell if the cable was connected by sensing a voltage, not essential but i do like the bells and whistles and the little things make a difference lol (thats a mum quote)
LG