DS18B20 (1-Wire) Support, why is it so problematic?

[Panhandle_Ponics]

I’m trying to help people use my Pi Hat with RPi clones and everything works, except for the DS18B20 temperature sensors. Using current versions of Armbian on both a Banana Pi M2 Zero, a Banana Pi M4 Berry, and an Orange Pi 3B, but no devices show up in /sys/bus/w1/devices.

 

/etc/modules contains:

 

w1-gpio
w1-therm

 

/boot/armbianEnv.txt contains:

 

overlays=w1-gpio
param_w1_pin=PA6
param_w1_pin_int_pullup=1

 

NOTE: PA6 is used so that it matches up with the default 1-Wire pin used on an RPi. These hats are already built, I can’t change this to a different pin.

Edited October 12 by Panhandle_Ponics

[robertoj]

Look for successful or failure experiences in SBCs with the same ARM chip.

For example, the banana pi zero m2 zero shares the same chip as the orange pi zero.

 

Execute dmesg|grep w1 to see if the kernel module is loaded

Look in the uboot messages, to see if there's an error applying the DTBO

Use gpioinfo to see if PA6 is not already claimed by the kernel for something else 

[Panhandle_Ponics]

Yep, already did that, my installer script loads those modules automatically. The problem is that there is a lack of w1-gpio overlays. The one on the M2 Zero is nonfunctional, and there isn't even one on my M4 Berry, nor is there one for my Orange Pi 3B. It appears that when they create these community generated Armbian distributions for the various SBCs, they're totally dropping the ball on the w1-gpio overlay.

 

I've gotten around the problem by writing a C program that talks directly to the DS18B20 temperature sensors on any GPIO pin. No more need to rely on the /sys/bus/w1/ directory.

 

Damn shame that they've dropped the ball on including the necessary overlay for those kernel modules to actually do something.