High Temperature and humidity meltdown!!

[407charles]

Have you ever experience a high temp. and humidity weather? It's very bad! I'm trying to design a control to track the ambient temp. and humidity to control a plant environment. I'm using the DHT11 humidity/temp. combination sensor with "One-Wire communication protocol. There is a couple examples in the flowcode wiki website but the examples are with the DS1820 blocks for this particular e-block, and the macros are built for this particular sensor (I think). I never perform any program in this communication protocol, and I'm having problems trying to make my program work. Can anybody help me with this please? I'm including my first attempt and the datasheet. Thanks a lot with advance. Any help is greatly appreciated.

[acestu]

Hi 407Charles,

This post might help you:

http://www.matrixtsl.com/mmforums/viewt ... 26&t=15303

Cheers
Stuart

[kersing]

The DHT11 uses one data wire to exchange data with the controller. However the protocol used is not Maxims (previously Dallas Semiconductors) 1-wire protocol. (Which is a proprietary protocol that requires a license to implement on a sensor.) As a result the One-Wire communication protocol implemented to talk to DS1820 devices will not work with the DHT11.

[acestu]

Hi Jac,

Thanks for that info very interesting, so a licence needed for the DHT-11 sensors one wire protocol...

Stuart

[kersing]

No, the protocol used for DHT11 is not the licensed protocol. One wire (1-wire) requires licensing from Maxim if you implement it in a slave device like a sensor. The master (controller) part can be implemented for free.
Again, this does not apply to the DHT11 as it uses a different protocol.

[407charles]

Thanks a lot.