June 22, 2026

The Dallas 1-wire protocol saga -- Past work

I did some digging around and rediscovered somw work I did on a driver back in 2021. I have an NanoPi (Allwinner H3 based) board connected to a DS18B20! This board is set up to run Kyu and among my Kyu sources I find: 
Kyu/src/h3/dallas.c
This driver mentions a Maxim app note "AN126". I find a copy of this at this location: 
/u2/Projects/NanoPi/Dallas/AN126.pdf
This note is 12 pages and entitled: "1-Wire Communication Through Software" and is dated May 30, 2002.

There are other things of interest in this directory 

AN126.pdf
AN162.pdf
DS18B20.pdf
MAX31850-MAX31851.pdf
AN162 talks about interfacing the DS18B20 to a microcontroller (14 pages). The datasheet itself is 20 pages.

The MAX31850 is something else altogether. It is a 1-wire interface chip for thermcouples (thermocouple not included). It comes in a 10 pin package. And! It turns out I have a couple of these on little breakout boards from Adafruit.

Have any comments? Questions? Drop me a line!

Tom's software pages / tom@mmto.org