wc32 temp sensor

Please help me,


I have 1 wc8, i plug my ds18b20 sensor to it and chose the sensor in the temperature setup page. I take the same sensor and plug it to my wc32, then try to find the sensor but I can only see
0000000000000000000000




what is the problem?

So sorry, it's fixed, I only reboot the board and it works!!!!

Yes, all the boards only probe the bus for sensor during power up.  If you changed the 1-wire bus configuration, it is better recycle power, or power it off when changing sensors on 1-wire bus.
 
WC32 has Maxim made 1-wire bus master chip, that supposedly work for any sensor, even in parasite mode, if the sensor chip support that mode.  However, in parasite mode, sensors work much slower, because during conversion, bus master must stop any activity on bus.  WC8 does not support parasite mode, so that I can communicate with all sensors without waiting.

So , if i'm right, I can run 300' of cat5e cable between the board and the probe without any prolems?

If you ran star configuration, you will have problem with much shorter cable.  However, if you just run a sensor on the end of cable, you will not have problem, if there are no noise alone the line.   When install wire harness, it is always tricky to make sure it is not picking up noise.  Maxim did testing the controller chip with 300ft cable.  That is why they published a few articles about how to run long wire for 1-wire bus.
 
If you plan to run long bus, please do consult Maxim web site or even their support engineers regarding how to best run the long cable.