device attached to the 1-Wire bus must have open drain or 3-state outputs. The 1 -Wire port of the DS18B20 (DQ pin) is open drain with an internal circuit equivalent to that shown in Figure 9. A multidrop bus consists of a 1 -Wire bus with multiple slaves attached. The 1 -Wire bus requires a pullup resistor of approximately 5 k .РThe idle state for the 1 -Wire bus is high. If for any reason a transaction needs to be suspended, the bus MUST be left in the idle state if the transaction is to resume. Infinite recovery time can occur between bits so long as the 1 -Wire bus is in the inactive (high) state during the recovery period. If this does not occur and the bus is left low for more than 480 s, all components on the bus will be reset.РHARDWARE CONFIGURATIONР+3V ・ +5VРРTRANSACTION SEQUENCE
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