Read DHT 11 temperature sensor and hum...

[livius]

i try to read data from DHT 11 sensor
my file dhttest.py looks like

from machine import Pin
from machine import UART
import DHT
dht_pin=Pin('G4', Pin.OPEN_DRAIN)
dht_pin(1)

temp, hum = DHT.DHT11(dht_pin)
# temp = temp * 9 // 5 + 320   # uncomment for Fahrenheit
temp_str = '{}.{}'.format(temp//10,temp%10)
hum_str = '{}.{}'.format(hum//10,hum%10)

# Print or upload it
print(temp_str, hum_str)

but when i do
execfile('dhttest.py')
result is
280.5 280.5
but second execution
execfile('dhttest.py')
cause halt exception

>>> execfile('dhttest.py')
280.5 280.5
>>> execfile('dhttest.py')
Guru Meditation Error: Core   0 panic'ed (Interrupt wdt timeout on CPU0)
Register dump:
PC      :  400d277d  PS      :  00060634  A0      :  80082d94  A1      :  3ffdc2a0  
A2      :  0006062f  A3      :  00000245  A4      :  00000001  A5      :  00000001  
A6      :  00000000  A7      :  3ffb0154  A8      :  00000001  A9      :  3ffdc280  
A10     :  3ffc4bf4  A11     :  0000012c  A12     :  00000122  A13     :  00000000  
A14     :  00000003  A15     :  00060223  SAR     :  00000004  EXCCAUSE:  00000005  
EXCVADDR:  00000000  LBEG    :  4000c2e0  LEND    :  4000c2f6  LCOUNT  :  ffffffff  
CPU halted.

code of dht.py is here
dht post

please help with this

[yahia]

This post is deleted!

[iber]

I got into the same issue with this DHT11 sensor.
I wonder if it still has to do with the threading issue as mentioned here.

Secondly, why is the call to dht_pin(1) required?
If I get it right, this writes a value of 1 to the pin?

*edit
Even without any sensor connected, the code still returns a fixed 28.05.

[yahia]

Hello.

I bought a grove sensor which contains DHT22 (now called AM2302) and i tried the code mentioned here and it does return 280.5 without crashing but nothing else. Does anyone know how to actually read the sensor data? or point me to the right direction?

I am using a LoPy by the way.

Thanks

[Roberto]

Hi @livius,

We released a new firmware with updates in stability that i think might help you with your issue, please download it at
https://www.pycom.io/support/supportdownloads/
and follow the instructions

Best,
Roberto

[livius]

With todays firmware it does not crash :)