DHT20 ESP32 NODEMCU

[miwi17null6]

Hello,

I flashed an esp32 nodemcu with micropython. a dht20 is to be used here. I connected it correctly, but I can't get the program to run. the i2c bus is recognized because it outputs the address 0x38.

i installed the dht20 library via tonny ide. (https://pypi.org/project/dht20-sensor/)

from dht20_sensor.sensor import DHT20Sensor

But there is always the error that the module could not be found.

how can i get the library on the esp32?

or to put it another way, does the dht20 currently work with the esp32?

[davefes]

Maybe check these out:
https://github.com/flrrth/pico-dht20
http://47.106.166.129/Embeded/pico-micropython-grove/blob/master/I2C/dht20.py

[miwi17null6]

https://github.com/flrrth/pico-dht20
I had already tried. but there is always a syntax error in line 99 dht20.py

http://47.106.166.129/Embeded/pico-micropython-grove/blob/master/I2C/dht20.py
seems to work. but how do I get the values from the class DHT20?
I'm still inexperienced in this regard, but I want to learn more...

[davefes]

I had already tried. but there is always a syntax error in line 99 dht20.py

Probably means there is an error in the line before, but I can't guess what it is. Copy the exact error to your next response.

but how do I get the values from the class DHT20?

temperature = dht20_temperature()
print (f'{temperature}')

should do it.

[miwi17null6]

I'm using this script right now http://47.106.166.129/Embeded/pico-micropython-grove/blob/master/I2C/dht20.py
I have a boot.py and a dht20.py on the ESP32
boot.py:

from machine import Pin, I2C
from utime import sleep

from dht20 import DHT20

temperature = dht20_temperature()
print (f'{temperature}')       #line 7

output:

Traceback (most recent call last):
  File "boot.py", line 7
SyntaxError: invalid syntax
MicroPython v1.13 on 2020-09-02; ESP32 module with ESP32
Type "help()" for more information.

if I delete line 7, the next error comes

Traceback (most recent call last):
  File "boot.py", line 6, in <module>
NameError: name 'dht20_temperature' isn't defined
MicroPython v1.13 on 2020-09-02; ESP32 module with ESP32
Type "help()" for more information.

I've been trying for a while now to get the values, but there are only errors. Can't really find any instructions for it. Anyone an idea?

[davefes]

At the REPL prompt >>> type help('modules') and see if DHT20 is in the list.

My v1.19.1 shows dht so try just import dht and see what happens.
After it is imported doing dir('dht') at the prompt does not show a DHT20.

https://docs.micropython.org/en/latest/esp8266/tutorial/dht.html
mentioned the DHT11 and DHT22.

import dht
import machine

d = dht.DHT11(machine.Pin(4))

import dht

import machine

d = dht.DHT22(machine.Pin(4))

But it looks like it is not in the ESP32 port. And there is nothing at https://awesome-micropython.com/

[miwi17null6]

It works!

I found this: https://github.com/mcauser/micropython-dht12 and using the script from here: http://47.106.166.129/Embeded/pico-micropython-grove/blob/master/I2C/dht20.py rewritten.

[miwi17null6]

import time
import dht20
from machine import I2C, Pin
i2c = I2C(scl=Pin(22), sda=Pin(21))
sensor = dht20.DHT20(i2c)

while True:
    sensor.read_dht20()
    print(sensor.dht20_temperature())
    print(sensor.dht20_humidity())
    time.sleep_ms(4000)

[CStrangi08]

What library did you install to import dht20?