1-Wire on wiringPi: missing w1 folder by path "/sys/bus/w1/devices/"

ysern

I'm trying to get DS1820 temperature and humidity sensor working on my raspberry pi 3 by running Example-wiringPi.

During the initialization of 1-Wire protocol, the Example-wiringPi tries to access path /sys/bus/w1/devices/, but unfortunately w1 folder is missing in the Emteria.

Does it mean that 1-Wire protocol isn't supported by the Emteria? Or I have to replace w1 with something else?

Thanks for the help!

IKS

Maybe you need to load the corresponding kernel module (see https://raspberrypi.stackexchange.com/questions/26623/ds18b20-not-listed-in-sys-bus-w1-devices)? All modules are located in /boot/modules

ysern

hello kalkov, thank you for referring me to the resource on the StackExchange.

I was googling a little about that. eventually, I've reached this article: https://pinout.xyz/pinout/1_wire

it is written there:

To enable the one-wire interface you need to add the following line to /boot/config.txt, before rebooting your Pi:
dtoverlay=w1-gpio

I opened config.txt and even have found similar line there:

dtoverlay=vc4-kms-v3d,cma-256

I added dtoverlay=w1-gpio in the end, saved, and rebooted. /sys/bus/w1 hasn't appeared.

Any ideas what can be wrong?

ysern

as I understand there is another way how setup 1-wire protocol, but it seems I've faced problems with that too.

in the Example-wiringPi there is a method that initializes 1-wire:

//1-Wire
private void insmod1Wire() {
try {
DataOutputStream os = new DataOutputStream(mProcess.getOutputStream());
os.writeBytes("insmod /system/lib/modules/wire.ko\n");
os.writeBytes("insmod /system/lib/modules/w1-gpio.ko\n");
os.writeBytes("insmod /system/lib/modules/w1_therm.ko\n");
os.flush();
Thread.sleep(100);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

I decided to execute insmod command localy on device using the terminal. File wire.ko doesn't exists by the path '/system/lib/modules/'. I managed to find it here: '/boot/modules/'. I tried to execute insmod with corrected path, but it has responded with the error that file doesn't exist:

insmod /boot/modules/wire.ko
insmod: failed to load /boot/modules.wire.ko: No such file or directory

IKS

I pointed you to that location in my last post:

@IKS said:
All modules are located in /boot/modules

You need to load them in the correct order and with root priviliges (su).

IKS

rpi3:/ # insmod /boot/modules/w1-gpio.ko
[ 1964.697588] w1_gpio: Unknown symbol w1_remove_master_device (err 0)
[ 1964.716717] w1_gpio: Unknown symbol w1_add_master_device (err 0)

Obviously, there is something missing. You need to find out where those functions are defined and load the corresponding module before loading this one.

akaungtay

I also encounter the same problem. Did you manage to find solution?