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META TOPICPARENT |
name="Solutions" |
Solutions to exercise 4: The DHT11 Temperature and Humidity Sensor
Exercise 1: |
| It takes a new measurement every 2 s and prints the result.
Exercise 2: |
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< < | The manual evaluation you must do yourself, the program for automatic data extraction is here: |
> > | When doing the manual evaluation you get:
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Combined |
Decimal Value |
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Humidity High |
0 |
0 |
1 |
1 |
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1 |
1 |
1 |
1 |
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0x3f |
63 |
Humidity = 63% |
Humidity Low |
0 |
0 |
0 |
0 |
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0 |
0 |
0 |
0 |
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0x00 |
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Temperature |
0 |
0 |
0 |
1 |
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0 |
1 |
1 |
1 |
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0x17 |
23 |
Temperature = 23.4°C |
Temperature Decimal |
0 |
0 |
0 |
0 |
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0 |
1 |
0 |
0 |
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0x04 |
4 |
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Checksum |
0 |
1 |
0 |
1 |
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1 |
0 |
1 |
0 |
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0x5a |
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Adding the first 4 hex numbers should result in the same value as the checksum:
The program for automatic data extraction is here: |
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https://afnog.iotworkshop.africa/pub/IoT_Course_English/SolutionsToTheDHT11TemperatureAndHumiditySensor/dht11Eval.py.txt
and here a screen dump when running it on the data taken: |
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< < | |
> > | |
| Exercise 3:
The exercise sheet pretty much explains how to proceed. Therefore I just supply the solution for your study. There are 2 different ways on how to convert the binary values in the 32*32 bit array to strings such that you can write them to the file. In the solution I use the newer method while the old style is given in the comments. |
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META FILEATTACHMENT |
attachment="dht11.py.txt" attr="" comment="" date="1589460999" name="dht11.py.txt" path="dht11.py.txt" size="739" user="UliRaich" version="1" |
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< < |
META FILEATTACHMENT |
attachment="dht11Eval.py.txt" attr="" comment="" date="1589464467" name="dht11Eval.py.txt" path="dht11Eval.py.txt" size="1986" user="UliRaich" version="2" |
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> > |
META FILEATTACHMENT |
attachment="dht11Eval.py.txt" attr="" comment="" date="1590848923" name="dht11Eval.py.txt" path="dht11Eval.py.txt" size="2009" user="UliRaich" version="3" |
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META FILEATTACHMENT |
attachment="dht11Result.png" attr="" comment="" date="1589462766" name="dht11Result.png" path="dht11Result.png" size="18985" user="UliRaich" version="1" |
META FILEATTACHMENT |
attachment="dht11RawRead.py.txt" attr="" comment="" date="1589463741" name="dht11RawRead.py.txt" path="dht11RawRead.py.txt" size="814" user="UliRaich" version="1" |
META FILEATTACHMENT |
attachment="dht11Unpack.py.txt" attr="" comment="" date="1589464428" name="dht11Unpack.py.txt" path="dht11Unpack.py.txt" size="1125" user="UliRaich" version="2" |
META FILEATTACHMENT |
attachment="dht11Plot.py.txt" attr="" comment="" date="1589464296" name="dht11Plot.py.txt" path="dht11Plot.py.txt" size="1109" user="UliRaich" version="2" |
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> > |
META FILEATTACHMENT |
attachment="dht11Eval.png" attr="" comment="" date="1590848923" name="dht11Eval.png" path="dht11Eval.png" size="20099" user="UliRaich" version="1" |
META FILEATTACHMENT |
attachment="dht11Checksum.png" attr="" comment="" date="1590849113" name="dht11Checksum.png" path="dht11Checksum.png" size="4735" user="UliRaich" version="1" |
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