Johnny-five: Support For DHT11

[roboflank]

I know this question has been asked some times back, i would just want to confirm if the library provides support for DHT11 now? or is it HTU21D alone?

[rwaldron]

Sorry, there is currently no support for the DHT11. There are many other temperature sensors that are supported:

• LM35
  
  
  
  • Mouser
  
  
  • TI
  
  
• TMP36
  
  
  
  • Adafruit
  
  
  • Analog Devices
  
  
  • SparkFun
  
  
• TMP102
  
  
  
  • SparkFun
  
  
• DS18B20 (requires ConfigurableFirmata)
  
  
  
  • Adafruit
  
  
  • Maxim Integrated
  
  
  • SparkFun
  
  
• MPU6050
  
  
  
  • Invensense
  
  
  • SparkFun
  
  
• Grove Thermometer
  
  
  
  • Seeed Studio
  
  
• BMP180
  
  
  
  • Adafruit
  
  
  • SparkFun
  
  
  • Grove
  
  
• MPL115A2
  
  
  
  • Adafruit
  
  
  • SparkFun
  
  
• MPL3115A2
  
  
  
  • Adafruit
  
  
  • Sparkfun
  
  
  • SparkFun Weather Shield
  
  
  • SparkFun Photon Weather Shield
  
  
• HTU21D
  
  
  
  • Adafruit
  
  
  • Sparkfun
  
  
• MCP9808
  
  
  
  • Adafruit
  
  
• SI7020
  
  
  
  • Tessel Climate
  
  
• MS5611
  
  
  
  • Amazon
  
  
• TH02
  
  
  
  • Grove
  
  

[roboflank]

@rwaldron i needed a hygrometer sensor apart form HTU21D

[rwaldron]

All of the supported components are listed on each API page, so for Hygrometer, there are currently two http://johnny-five.io/api/hygrometer/

I will look around for others that can be added for more device diversity

[rwaldron]

The best I can do for now is to provide support via an I2C backpack, which means you'll need another microcontroller, any arduino will do the trick.

[rwaldron]

In v0.9.35...

• https://github.com/rwaldron/johnny-five/blob/master/docs/multi-DHT11_I2C_NANO_BACKPACK.md
• https://github.com/rwaldron/johnny-five/blob/master/docs/hygrometer-DHT11_I2C_NANO_BACKPACK.md
• https://github.com/rwaldron/johnny-five/blob/master/docs/temperature-DHT11_I2C_NANO_BACKPACK.md

var five = require("johnny-five");
var board = new five.Board();

board.on("ready", function() {
  var hygrometer = new five.Hygrometer({
    controller: "DHT11_I2C_NANO_BACKPACK"
  });

  hygrometer.on("change", function() {
    console.log("Hygrometer");
    console.log("  relative humidity : ", this.relativeHumidity);
    console.log("--------------------------------------");
  });
});

[soundanalogous]

nice! especially considering the odd timing delays the DHT11 requires. Offloading it all to I2C keeps things unblocked in the main processor.

[rwaldron]

Yeah, I figured it was about time I addressed this sensor ;)

My next iteration will be to allow specifying either the DHT11 or DHT22

[roboflank]

Great, just what I needed 🙌.

[roboflank]

For the meantime I will close the issue, let me try to implement it, will reopen the issue incase of anything.

[rwaldron]

@denzelwamburu sounds good!

[eugenebessan225]

hello! Please, i'm working on an automatic systèm for greenhouse. it's my project in order to obtain my bachelor and i face to certain difficulty with johnny five. My DHT22 sensor returns 0 as result and i d'int know what's happened. help me pls

[dtex]

It's hard to help without more information. Can you share code and a picture of your wiring?

[eugenebessan225]

````js
const { Board, Thermometer } = require("johnny-five");
const board = new Board();

board.on("ready", () => {

const thermometer = new Thermometer({
controller: "DHT22_I2C_NANO_BACKPACK"
});

thermometer.on("change", () => {
const {celsius, fahrenheit, kelvin} = thermometer;
console.log("Thermometer");
console.log(" celsius : ", celsius);
console.log(" fahrenheit : ", fahrenheit);
console.log(" kelvin : ", kelvin);
console.log("--------------------------------------");
});
});
````

Here is my code

[eugenebessan225]

i've just copy this here. And in arduino, i'he televerse the standard firmata code.

It's hard to help without more information. Can you share code and a picture of your wiring?

[eugenebessan225]

i'm trying to upload the wiring but i can't.

[dtex]

returns 0 as result

For Celsius only right? You're getting 32 and 273 for the others?

Also, I just want to make sure that you've uploaded the backpack sketch to the second board.