Did you wire in the 4.7k resistor
select configuration
select configure module
set to generic(18) for the module type
then set D2 to be temp sensor. (I forget the wording on this one)
it is showing the configuration in picture for the pressure sensors not the temp sensor. so don't use i2c that is shown in picture.
I am using a Wemos D1 Mini. I flashed the firmware with Tasmotizer, choosing tasmota-sensors.bin and ticked "Erase before flashing" (My ESPs have peviously had the Arduino firmware installed).
Once it says it has successfully flashed, I use "Send config" to setup wifi and MQTT details (You have to tick the tiny invisible checkboxes next to Wifi and MQTT).
Give it a little time to connect to the wifi then Get IP (or other means of showing connected devices) then point a browser to it.
As @9toejack says, Configure Module, set the module type as Generic (18) and the SCL and SDA pins.
Edit - The BME280 sensor I'm using does not need a 4.7K resistor,
Go to Console and enter the command restart 1.
As it restarts you should see this:
BME280 data is also available via the command status 10
i2cscan is also a useful command - it will give an error or else the I2C address of the sensor.
Yes, I wired it correctly.
But do i need to connect the DS18B20 data wire to D2?
Because D2 (gpio4) is the SDA pin of the ESP8266 if i am not mistaken
So do I label that pin (in configure) as DS18B20 or SDA
D2 SDA
D2 DS18B20
I am confused 
I said in that photo ignore the sda, you can use any gpio that will show you to change it. You need to select do down and select I believe is ds18xx0 something weird like that
@WBr use gpio 14 and in drop down select
"Ds18x20"
That should get you working. Sorry i had just sent to bed. But got up to get the correct selection. You can use d2 wich is gpio4 however if you plan to use i2c, you need to leave d1 and d2 alone.
I use gpio14 which is d5
Can you point to where you read that?
@jbudd
When using one, even in the esp8266 had an internal pullup resistor you can turn on. But it really isn't the right size and from last year I'd using it that way, i found it is better to use the 4.7k resistor like maxums web sight says.
I posted in reply to @WBr asking how I set up Tasmota-sensors for BME280.
I have not read every post in this thread so I don't know what @9toejack's reference to a 4.7K resistor is about, but I have the ESP and sensor successfully sending data to MQTT without one.
It did trigger a memory that I read of a need for a resistor for some purpose when using a bare ESP8266, along with a picture of a development board showing the resistor for that purpose is on the board. I can't find this page now of course.
So I don't mean to undermine the advice that you need one.
I should have said "I'm not using a 4.7K resistor, what is that needed for?"
Apologies for muddying the water.
I think it is better to use an external resistor. It may work ok without one, but possibly only if the device is on a short lead and in an area of low electrical interference. The purpose is to make sure the data line pulls up fully when the sensor is not pulling it down.
Can you point me to where this resistor is prescribed? Maxums website?
I'm in the dark here!
Maxim were taken over by Analog Devices.
Understood. Different sensor.
I2c bus should also be pulled up (typically 10k).
I do not use a pullup resistor with the i2c communication , I use the ads1115 (originally Texas Insterments) here is the first page about the ads1115 with a block diagram.
Most i2C sensors have pullup resistors built in.
As long as a least one device on the bus has pullups then it should be fine.
The only problem would be if you have a lot of devices on the bus with pullups as the resistance is decreased with each extra device and "could" become too low for the devices to pull the bus low.
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