Hello,
I've made a DS18S20 -based serial port temperature sensor. I would like to connect it to the usb port on my Asus WL-500gp v2. The temperature sensor works perfectly on the pc connected to a serial port directly, but I can't get it to work with my usb-rs232 serial port adapter. I think the problem with my circuit is that the serial port adapter supplies only 5 volts (like usb does) and a "real" serial port should supply a little bit more..?
I know I could take the power from elsewhere but it would be easier to take it from the serial port.
Has anybody made a similar project, could someone show me a circuit that would work using a usb-serial port adapter?
Here is the schematic:
http://elektroniikka.org/thermometer/images/ds9097e.gif
Hope somebody can help..