|
Here I attempt to simulate the 1-Wire Communication Protocol which was established by Dallas Semiconductors, which was later acquired by Maxim Integrated.
The left network is the Master and the other (right) network is the Slave.
The slave powers its circuitry via a capacitor, which is charged through the main dataline. This means that only 1 wire is used for the Data and Power line. However, this implies that the data should be passed at a lower speed so as not to discharge the capacitor and turn off the circuit. This also means that the data line should be at logic "high" most of the time, hence, the protocol uses active low. The data line is pulled to 5V during quiescent via a pullup in the Master device.
Although the term 1-wire is used, a ground connection is still needed.
In this circuit, I have timed the logic trains for the master and slave to trigger/transmit once and twice respectively. The lamps in each circuit is there to represent properly received data. In reality, this would be replaced by a digital block that interprets the data, and the timing would be different.
Connect the main line first via SPST switch in the middle, then activate the logic trains via the switches near them to simulate comms.
The LED on the right represents the circuit's loading on the capacitor. The values were chosen arbitrarilly, however, it should give the idea.
Enjoy!
|
