The Dallas 1-wire protocol saga

I decided to call this a "saga" rather than a "blog". Why not? I hope you are amused.

This protocol was developed by Dallas Semiconductor back in 1999 perhaps. It was designed for very low bandwidth devices with the priority on simplifying circuitry.

Dallas was acquired by Maxim around 2001 or so. Maxim was acquired by Analog Devices sometime after that. I haven't bothered to dig to deep into the history, but whatever the case in 2026, Dallas is now part of Analog Devices.

• Introduction
• Past work
• AN126
• First experiments with Kyu on an h5 system
• Trouble in Kyu land
• Experiments with the DS18B20
• Experiments with the DS1994
• More experiments with the DS1994
• the DS1994 scratchpad
• writing to DS1994 memory
• date and time from the DS1994
• a full test of the DS1994 and conclusion

The end of this work is this driver written in C:

• dallas.c

My interest began with the DS1994 you can see pictured above. It came from a Raman spectrometer; you can find more background here:

• The Thermo Scientific DXR Raman instrument