If you look at the specification sheet you see a 0.3-0.4 C accuracy for the Si7021.
It can therefore be that one sensor always gives the temperature - 0.3
C and the other gives temperature + 0.3
. If you want absolute precision you need to calibrate your sensors. In the formulation field of your sensor (in espeasy) you can then use %value%-0.3
for example. I did that as wel for one of my ds18b20 sensors (and I was far too lazy to do it for the others)
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Lan Sensors
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@Harry-van-der-Wolf: Thanks for Help
It work
My precision was between +2 or +3.
The precision of -0.3 or +0.3 it is ok for me.
But i have forget to write, that i have put the sensor und esp8266 on a board.
If I put more disance between sensor and the esp8266 with cabel ( 5 cm )
The senor shows the right themperature.For all Beginners …
I do not know why but it is soI will have more answers at next time.
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If you touch the CPU of your ESP you will feel it gets warm. I do not know how much warmth is dissipated but if the temp sensor is really close to the CPU I can imagine it gets warmer.
But that’s some guessing from my side. -
@mwittig: My LAN Shield (NC28J60) will not work. Which LAN Shield do you use?
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@SOJ said in Lan Sensors:
Which LAN Shield do you use?
I am using a clone of the Arduino Ethernet Shield which is based on the Wiznet W5100 ethernet chip.
"It always takes longer than you expect, even when you take into account Hofstadter's Law.", Hofstadter's Law
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@SOJ said in Lan Sensors:
@mwittig: My LAN Shield (NC28J60) will not work. Which LAN Shield do you use?
I am also using Wiznet W5100. Now I have ordered Nano V3 Ethernet Shield - ENC28J60. I will let you know.
Pimatic = Smart Home
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Hey @SOJ,
yesterday I arrived ethernet card ENC28J60. With the library <EtherCard.h> I did not have success. But with the UIPEthernet on the first attempt. In most sketch, just change<Ethernet.h>
to<UIPEthernet.h>
.
For measuring temperature and humidity I want to use Si7021.To do this, I want to order the PoE module. But the shipping price is terrible. Common order would have been good. Is there anybody who adds?
Pimatic = Smart Home
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The ethernetshield work with the UIPEthernet.
But i can not install the StandardFirmataEthernet.
Which sketch you are use? -
Which sketch you are use?
From the github or I write own. Do you have specific cases?
Otherwise, I found the <UIPEthernet.h> requires much more memory than Ethernet.h. The W5100 can either be use with TFT Bootloader.
Pimatic = Smart Home
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Thanks for your help. I have buy some W5100 and i will test it later.
I have preferred so other pimatic sub project.
It come the winter an my heating will not work correct.