2147483647 value intermittend, DHT11 NodeMCU and Blynk

Need Help With My Project
21

I’m guessing that’s a typo?

You shouldn’t use delays with Blynk, they block all code execution during the delay period. The better approach is to use BlynkTimer to call the function that takes the readings, and set the timer period to the appropriate time in milliseconds (2000 for a 2 second reading cycle).

As I’ve said earlier, the DHT range of sensors are total junk, and the results you get from them are far from accurate. The AM2320 azrent much better in my experience. You’re much better-off with a different type of sensor. I’d preciously recommended the BME280 but my current favourite is the SHT30 as these are available in waterproof versions that can be used in an external weather station, as well as regular versions that can be used indoors.

Pete.

22

Dht22 are fine for temp sensing, for HVAC scenarios. But i have a bunch of AHT10s that I’m going progressively replace the Dht22 sensors.

(my “important” sensors are all BME280 to be fair)

23

To clarify I’m not using Blynk but this post is the first that described the issue I also had. I’m on PlatformIO/ESP8266/C++ using the Adafruit AM2320 libraries.

I agree precision wise there are far better sensors for temperature and air humidity.

The 0.5Hz is AM2320’s sampling frequency (can sample data once every 2 secs). Not a typo if that’s what you were referring to.

24

Yes, 0.5Hz is once every two seconds, but you said once every second, not once every two seconds.

So I guess it is a typo?

Pete.

1 Like
25

“this post” is from 2016, so if you have issues, ‘back to basics’ is your first step…

26

I see what you mean.

Yes, for the DHT11 it’s once every second (1Hz). So the delay should normally be at least 1000ms.

27

Do you think that the temperature will change every second? :rofl:
I use a AHT20, I read it every 2 minutes that’s enough to control HVAC unit.

1 Like