CAI_Support
Senior Member
The link you provided is no longer viewable on eBay. Don't know why.
Without seeing what those switches are and how they are internally constructed, we don't know for sure.
1-wire bus is a digital communication bus. DS18B20 actually sends its temperature in digital format with checksum. If that checksum is not correct, WebControl toss out that reading. Thus, it is pretty sure the DS18B20 reported the temperature. The temperature difference for 2 degree might due to one sensor is closer to some object and other sensor is not. Even in the same room, different sensor locations could read back different values.
The circuit you provided requires WebControl to send signal to pull up the bus. That is when there are parasite device on the bus. WebControl 8 does not support that currently, because that will require more CPU attention. WebControl 8 CPU is constantly being interrupted by other tasks, doing so will not work well with one CPU handle everything. Most people running cat5 cable for 1-wire bus, which could easily run the 5V in that to the sensor. On our WebControl32 board, there is a dedicate 1-wire bus controller to handle the 1-wire timing, that will allow parasite devices.
Without seeing what those switches are and how they are internally constructed, we don't know for sure.
1-wire bus is a digital communication bus. DS18B20 actually sends its temperature in digital format with checksum. If that checksum is not correct, WebControl toss out that reading. Thus, it is pretty sure the DS18B20 reported the temperature. The temperature difference for 2 degree might due to one sensor is closer to some object and other sensor is not. Even in the same room, different sensor locations could read back different values.
The circuit you provided requires WebControl to send signal to pull up the bus. That is when there are parasite device on the bus. WebControl 8 does not support that currently, because that will require more CPU attention. WebControl 8 CPU is constantly being interrupted by other tasks, doing so will not work well with one CPU handle everything. Most people running cat5 cable for 1-wire bus, which could easily run the 5V in that to the sensor. On our WebControl32 board, there is a dedicate 1-wire bus controller to handle the 1-wire timing, that will allow parasite devices.
