W1-therm Onewire 18b20 Sensor Not Working - OpenWrt Forum

Có thể bạn quan tâm

For Developers novski April 21, 2020, 8:15pm 1 I built my own v19.07.2 with kmod-w1 and kmod-w1-gpio-custom as well as the desired kmod-w1-slave-therm for a Linkit Smart 7688 Target. I added echo "w1-gpio-custom bus0=0,19,0 bus1=1,20,0" > /etc/modules.d/55-w1-gpio-custom as described in the docs. I also checked the GPIO as described here. But the connected device (i double checked and even tried a second absolutely new 18b20) does not apear. In fact there are randomly changeing ID's apearing in the Kernel Log like these last 6 lines:I read a lot in raspi forums and had to regret that the /overlay stuff is not in my knowledge range. It maybe also differs to what openwrt is because it seems to be another way to do same things. I then tried to understan the kernel.org description but without success.What can I do more? AndrewZ April 21, 2020, 8:23pm 2 Let me share my notes on this. Modules required: kmod-w1 kmod-w1-gpio-custom kmod-w1-master-gpio kmod-w1-slave-thermUsing gpio5: echo "w1-gpio-custom bus0=0,5,0" > /etc/modules.d/55-w1-gpio-customFinally: cat /sys/devices/w1_bus_master1/28-xxxxxxxxxxxx/w1_slave novski April 22, 2020, 6:11am 3

cat /sys/devices/w1_bus_master1/28-xxxxxxxxxxxx/w1_slave

interessting path. My device shows at that path:I think i have found the /sys/bus path in this resource. It seams to be the same in a reduced way.I have also added the right GPIO. My first post has a copy and paste failure from the docs to this thread. It is not quite what I have done really as I have set GPIO 1:not GPIO 19 & 20:

I added echo "w1-gpio-custom bus0=0,19,0 bus1=1,20,0" > /etc/modules.d/55-w1-gpio-custom

its visable here: root@openwrt:/etc/modules.d# cat 55-w1-gpio-custom w1-gpio-custom bus0=0,1,0 root@openwrt:/etc/modules.d# cat w1-master-gpio w1-gpio root@openwrt:/etc/modules.d# cat w1-slave-therm w1_therm I uninstalled kmod-w1-slave-smem, still no sensor is found. Don't know what to do... anon50098793 April 22, 2020, 6:20am 4 novski April 22, 2020, 7:57am 5

cat /sys/devices/w1_bus_master1/-/w1_slave

Thanks! Here the answer:?1 Like anon50098793 April 22, 2020, 8:00am 6 p.s. i don't know much about i2c just filling in till @AndrewZ gets back... these seemed like the next step based on what you guys have written... but I suspect your issue is lower level.based on

[ 2884.519815] w1_master_driver w1_bus_master1: Attaching one wire slave 00.ec0000000000 crc 4a

i believe with one-wire it often needs some sort of pull-up/down somewhere... for bias/reference AndrewZ April 22, 2020, 8:11am 7 I suggest to check (or even try another) gpio port, sensor wiring and, finally, the log file. I don't have 1-wire configured right now, so cannot show you the desired output. Maybe @anon50098793 can provide an example from his log.1 Like AndrewZ April 22, 2020, 8:13am 8

i don't know much about i2c

i2c is absolutely different story. Actually, I switched from 1-wire to i2c in order to put several devices I had on the same bus.1 Like anon50098793 April 22, 2020, 8:22am 9

provide an example

alas, i've only used these things on uC/microcontrollers...

, having said that 9/10 it's a wiring issue... AndrewZ April 22, 2020, 8:45am 10

I have set GPIO 1

I'm a bit skeptic about using gpio1... what is your router model? Can you try another gpio? Better to check it with multimeter before configuring 1-wire stuff. novski April 22, 2020, 8:54am 11 My "router" model is a Linkit Smart 7688 and i have doublechecked the gpio by deleting the file in /etc/modules.d/55-w1-gpio-custom rebooting and toggle the gpio 1 whith this script stolen from the docs:and executeing it like that:While measuring the voltage on the pin 13. That pin goes to 3.3V when ./gpio 1 1 1 is given. So the wiring seams to be good.But granted, the pin can be not able to handle w1. I will solder it to another Pin and check. Thanks for the thoughts in the meanwhile, very appreciated. anon50098793 April 22, 2020, 9:25am 12 is this how its wired? ( pull-up to 5v or 3.3 )? you measured the logic levels in circuit?

AndrewZ April 22, 2020, 9:33am 13 Checked the dts file - even gpio1 should be good. novski April 22, 2020, 7:18pm 14 Yes that's how its wired. I have a Ground as well so my connection has 3 wires in total.

3.3V

Data

GND

Data and 3.3V are connected over a 4.7k Resistor. Data goes in to P13 = GPIO11 Like novski April 23, 2020, 6:51pm 15 I now changed the W1 Data wire to GPIO2 with no success. I have a previous built device in my house with 12 18b20 sensors on same Linkit Smart 7688 (it's productive) but that one is on OpenWrt SNAPSHOT r11009-4a85748040 / LuCI Master (git-19.264.32154-6dba41c) and it works on the GPIO2. I do not know how to compare what changed between that (wrongly built master branch) and the v19.07.2 tag. Is it possible to compare those two somehow? anon50098793 April 23, 2020, 11:49pm 16 rule out faulty sensor first.1 Like novski April 24, 2020, 10:15pm 17 OMG. GPIO1 does not work but GPIO2 does. I realized today, I forgot the 4.7k resistor on my test yesterday with GPIO2. What's the difference between GPIO1 and 2?