I would simply bit-bang the interface to the 1-wire device. The time per put is about 10 µsec and it is reasonably feasible to keep the microcontroller interrupts disabled during the combination of two delays that make up a bit transfer time. Since 1-wire communications allows an indefinite time between bits then it is feasable to re-enable the CPU interrupts after each bit time. This permits other interrupts that are able to live with a latency of up to 12-15 µsec to be processed.

If you cannot live with the latency for other interrupts while you software bit-bang a 1-wire device then you have three choices to follow:

A) Use a low cost small pin count microcontroller to interface to the 1-wire device and then connect that device to the main microcontroller via some other more conventional type of interface.

B) Make a byte transfer engine for 1-wire inside a small CPLD.

C) Select a microcontroller that has onboard hardware support for 1-wire devices.

Michael Karas