DHT11, DHT22 Sensors


#1

Will there be support for these sensors? Or is it already included? Thanks in advance…


SI 7021 support - temperature and humitidy I2C
#2

Yeah I am also wanting to use this sensor so far without any sucesss


#3

@Mr.Allen @maurifree These sensors are not supported, but we definitely will support them!


#4

Adafruit has some python libraries (Raspberry Pi, Beaglebone Black) for the DHT sensors. I’m messing with it now to see if they work with Cayenne. But, just incase you guys want to get started too, I thought I’d let you know.


#5

I’ve already used the said library from Adafruit together with Webiopi before. I’ve also used it to send data to Thingspeak. Just wondering if the team would natively detect/support the sensors, in which was already been confirmed by bestes…


#6

Also I’d like to see support for the MAX31855. For any industrial monitoring, you really need a referenced thermocouple sensor, this is a really good one. I was using the MAX6675, but in winter it becomes fairly inaccurate as the ambient is not controlled. The 31855 solves that.

Adafruit has a development board and some Python code for it. https://www.adafruit.com/product/269

@bestes, is there some driver framework documents to aid in developing a driver? I’d happily develop and test a driver if it will be included in future updates.

Craig


#7

I’ll add MAX31855 to the list for hardware.

Let me get back to you about developing a driver…need to talk with @eptak. This is something we’ve talked about, but really haven’t had the time to come up with a plan. Because ultimately, we want to enable you as a Cayenne user to put whatever device you want into the dashboard. Also have plans to allow you to insert custom code into Cayenne for widgets…I might be reaching out to you, and a few other Cayenne users, to talk more about this :slight_smile:
-B


#8

Cheers Benny.

It would be nice to think about how we organize driver by type or by interface.

For instance the MAX6675 and MAX31855 have the same electrical pin out, but the readback is slightly different.

The popular, LM74, has similar output, but a different range, and some registers for setting up a shutdown output. It would be interesting to create a super set widget after a review of the temperature sensors in your list, and either autoconfigure, LM74/75 has an ident, or allow selecting features - for instance, I’m not using the shutdown output, so don’t show the settings or output in the widget.

In the old days when developing ATCA chassis, we’d just run a script that would ident all the connected hardware on the I2C bus. Perhaps that would be the most intelligent way to handle some of this… then only natively support the stuff that we can positively identify.

…anyway, rambling. Beer time.

Craig


#9

I too would like to see these sensors supported. I was hoping to port an older design that I had running on arduino with electric imp to Cayenne on the Raspberry Pi.

Like @kreggly, I’d be interested in helping to contribute a driver if it helps.

Thanks,

Will


#10

@will, Eric had this to say when I requested to make a driver a while ago:

You can provide us the python script file so we can integrate it the driver in a later release. right now it’s not possible to add your own driver.
You will need to integrate your file into sensor folder from the webiopi sources, add it to init.py in the same folder, then rerun install.

I did some fooling around, but my driver just caused the install to halt. Haven’t troubleshot past that.

Cheers,

Craig


#11

Hi @kreggly,

Thanks for the info. I’ll play around with it and see what I come up with.

Cheers,

Will


#12

I’m thinking about picking up some DHT22 sensors as well


#13

Implementing MQTT would solve many issues IMO. No need to worry about drivers, etc. I have the DHT11 connected to my Pi sending sensor values to my MQTT Broker via a python script using node-red. The lack of MQTT support is the only thing stopping my from using this for my home IOT project. Hope to see that change in the near future.


#14

Would be great if you could attend the online meetup and we talk a little bit more about this.

-B


#15

This sounds awesome @mat_oldaker.

How does MQTT handle security/encryption?

Craig


#16

Along the same lines but probably easier to integrate would be the MAX31850. It connects to the 1wire bus and uses the same commands as the DS18B20. I’ve tried adding it manually using the unique serial number and it doesn’t report back a value.


#17

Add me to the list of people wanting support for DHT11/22. I am building a small growbox and the BMP180 doesn’t provide humidity readings.
Thanks,
Bruster


#18

me also
i realy need the dht22 support
thanks
J


#19

I´m also looking to build a small growbox, and its seems the DHT22 is the sensor I need! Please support it.

Also, where I can find a list with compatible sensors for cayenne?

Thank you for this great product! Nice job, keep going


#20

It will be supported eventually. If you wanted to write a driver for it I can reach out to you and give you the documentation. We’re pretty full working on getting Arduino support out the door for the time being.

Here’s the current list:

Keep us updated with your growbox project!

-B