Which library for DHT11 AND Nano 33 IOT

Official Hardware Nano Family Nano 33 IoT
1

Hi,
a very simple question.
I need to connect a DHT11 to a Nano 33 IOT ( together with a capacitive soil moisture sensor).
While I was able to have both of them working on Arduino Uno I was not able to find a library worhing with Nano 33 for DHT11.
Could you please tell me which library I have to use for Nano 33 ?
Thanks

2

I recommend you forget the DHT11 and use Bosch BME280 and the Adafruit library.

I know that was not your question but you upgraded your Uno to the 21st century now its time to do the same for the sensor. :slight_smile:

1 Like
3

Hi Klaus
Thanks for your advice
I'll follow your suggestion
However coming back to my question do you know which library I could use for DHT11 and Nano 33 ?

4

Hi bruno1950,

Using the IoT cloud full editor > Under Libary Manager > Search for DHT & use the DHT Sensor Libary

Although you would do much better to take the recommendation @Klaus_K & use a BME280 instead of a DHT11 as the DHT11 sensors are not very accurate!

HTH?

5

What is the expected bad accuracy? Greater than what percent? Or is it an inaccuracy at high or low or all temperatures? Thanks.

6

Hi
Thanks for your precious info.
As soon as I come back home I'll try the library.
Then I'm going to order a new sensor as advised

7

Hi bruno1950,

I'm using since 2 years an Arduino Nano 33 Iot with 3 different temperature sensors on the same board:

  • DS18B20
    -DHT 22
    -BME 280
    within a weather station on my balcony connected via Wifi with Thingspeak.

The library I'm using for DHT22 is DHT.h and below an image that makes a comparison of temperature readings across the 3 different sensors.

Depending on specific purpose of your project you can decide if that differences are really relevant or not.
image

Legend:
orange BME280
blue DHT22
Yellow DS18B20
The above graph reports last 10 measures

In my experience BME280 is more interesting since has temperature, humidity and barmoetric pressure measures, while DHT22 in the long run has by far less NaN values in comparison with both BME280 and DS18B20.

But is only my experience based on about 20.000 readings with a "for fun" home weather station.

BR

Andrea

8

Hi apagliari
Thanks for your detailed info; I tried according to your suggestion and it works.
Thx again.
Since you solved my problem, can I ask you if you have any idea why a RTC 1307 and an Oled 1306 SS work when connec ted to an Arduino Uno but NON on Nano 33 ?
I posted this question in the forum in the Nano 33 IOT category but I was not able to find a working solution.
Thx again

9

Hi bruno1950,
I'm sorry but I've never used neither RTC 1307 nor Oled1306. Can't provide nothing but a generic answer related to the fact that while Arduino Uno has 5 Volt pin IN&OUT signals, Nano 33 Iot has 3.3 Volt pins.

Which means that not all sensors and attuators can work easily with both Arduino Uno and Nano 33 Iot.

Having said that, which I know isn't a big help, you should verify if RTC 1307 and Oled1306 can work indifferently at 5 volt or 3.3 volt.

Sorry for the general answer I'm providing here.

andrea

10

Hi Andrea
THX for your help.
However, after many trials ed errors, I was able to have both the RTC and the Oled working, one through SPI and the other through I2C.
Best
Bruno

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