OneWire Utilities: Built for Speed

Simultaneous read operations help growing networks stay fast

Our simultaneous read algorithms allow the creation of large networks while overcoming the principle limitation of 1Wire devices: speed. With OneWire Utilities, you can read extended networks at speeds approaching that of a single device, compared to typical sequential reads that scale linearly with device count:

How it works

A typical read operation of a 1Wire device consists of three steps:

• Initialize conversion: Instructs 1Wire device to perform a conversion operation to copy the read value (e.g. temperature, humidity, voltage) into a non-volatile memory location for reading. Issuing this command typically takes 10-80ms.
• Wait for conversion: Before the value can be read, the conversion must be completed. A typical conversion operation takes from 75-800ms, depending the precision of the read operation.
• Read calculated value: Read the calculated value from the conversion operation. This process typically takes 10-80ms

To read multiple devices, the simplest and most commonly used method is to repeat the three steps above in the read operation. The result, however, is the majority of time being spent idly waiting for the conversion to take place. A more efficient method is to request all device conversions simultaneously, and return later to sequentially read the calculated values. Another benefit of this method is that the overhead for issuing multiple conversion times is included in the conversion wait time.