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[SOLVED] DS18B20 not found

Posted: Wednesday 23 November 2016 12:07
by RRM13
Hardware: Raspberry Pi3
Domoticz: Version: 3.5877

After reading and following several tutorials on howto connect a 1Wire DS18B20 sensor to the GPIO of the Pi nothing happens.
As I understood the sensor should be found automatically in 3 or 2 wire (parasitic mode) connection.
Tried:
- Installing the 1Wire hardware/device: 1Wire: Device not yet supported in Kernel mode (Please report!) ID:00-4c0000000000, family: 00
- In config.txt: dtoverlay=w1-gpio-pullup,gpiopin=4 even tried dtoverlay=w1-gpio,gpiopin=4, dtoverlay=w1-gpio
- Connect 6 different sensors to 3.3V, GPIO4 and GND with a resistor 4.7KOhm
- Measure Voltage on GND and 3.3V

Image

I'm completely lost after making the first Domoticz steps.

- Are the 6 sensors out of order?
- Did I connect them wrong?
- Should I update the kernel for 1Wire support (couldn't find a clear tutorial)?
- Change settings in Domoticz?
- What Voltage should be measured?
- Why are they not found in Domoticz and through SSH in the filesystem?
in /sys/bus/w1/devices there is only 00-800000000000 and 00-880000000000, but no sensor starting with 28-

Re: DS18B20 not found

Posted: Thursday 24 November 2016 10:10
by stlaha2007
Step by step check:
- rpi pin 1 3v3 to resistor (4k7 till 10k Ohm)
- also to redlead of sensor
- other end of resistor to yellow on sensor
- other end of resistor to GPIO4 pin 7
- black lead to rpi ground pin 6 or others ground pins

As you seem to have it working this way, next..
Message not 'yet' in kernel..
Update/Upgrade your kernel... it's in there for about 3years.

Next enable 1wire...

Also if it reports 00- instead of, the remark at adafruit tells you to cd (change dir) to 'what' you see.

Let me hear if you got things right. I doubt it's 6 DOA sensors ;-)

Re: DS18B20 not found

Posted: Thursday 24 November 2016 21:19
by RRM13
stlaha2007 wrote:Step by step check:
- rpi pin 1 3v3 to resistor (4k7 till 10k Ohm)
- also to redlead of sensor
- other end of resistor to yellow on sensor
- other end of resistor to GPIO4 pin 7
- black lead to rpi ground pin 6 or others ground pins

As you seem to have it working this way, next..
Message not 'yet' in kernel..
Update/Upgrade your kernel... it's in there for about 3years.

Next enable 1wire...

Also if it reports 00- instead of, the remark at adafruit tells you to cd (change dir) to 'what' you see.

Let me hear if you got things right. I doubt it's 6 DOA sensors ;-)
Although everything was connected exactly the same, I started with your step by step procedure and used new wires.
Fortunately, the sensor is displayed in Domoticz and reports nice temperatures. (I felt quite stupid.......)

There is no 1Wire error code anymore in the log.
Logging in with my iphone I discovered that the device tab of the 1Wire device has several options of OWFS, sensor/switch poll, which isn't displayed in the browser (Firefox and IE) of my computer.

But after connecting a second one, everything is gone again.
Maybe I have to get a breakout/breadboard to get better connections between the wires.

Re: DS18B20 not found

Posted: Friday 25 November 2016 0:04
by stlaha2007
Glad you got some luck... And don't feel stupid.....Can happen faulty wire/connection.

However i have read somewhere that the resistor can fool you. Sometimes a resistor towards 10k Ohm is necessary, for 1 a 4k7 Ohm would be sufficiant.
You better search the internet for that, it was more than a year ago, eventually i'm gonna get myself a few in a few days....

And get yourself a multimeter, perhaps again a faulty wire or faulty connection.
And yes get yourself a breadboard.... Have 1 hanging on my development Pi ;-)


Sent from my K00C using Tapatalk

[SOLVED] Re: DS18B20 not found

Posted: Wednesday 04 January 2017 11:32
by RRM13
With a breadboard two DS18B20 sensors were connected without any problem.
Connecting, in total, six sensors did only display the first two in Domoticz.
In the log file, the sensors weren't recognized.
Changing the resistor from 4k7 ohm to 10k ohm displayed all sensors in Domoticz.

Re: [SOLVED] DS18B20 not found

Posted: Monday 23 January 2017 12:04
by tontze
Interesting thread, i happend to have one DS18B20 laying around. But, i have razberry2 installed on my pi3, do any1 know can i still use this 1wire connection ?

-Tontze