Arduino Webserver Temperature Sensor

Arduino web server using an Ethernet Shield and 1-Wire temperature sensor to output XML, JSON, JSONP or Prometheus (prom format) response.

• Adapted by Gordon Turner from code by David A. Mellis and Tom Igoe.

• Ethernet shield attached to pins 10, 11, 12, 13

• 1-Wire temperature sensor attached to digital pin 3.

• Requires 1-wire Ardunio Library and Dallas Temperature Control Arduino Library.

• Included in Libraries folder or online: http://www.pjrc.com/teensy/arduino_libraries/OneWire.zip http://milesburton.com/Dallas_Temperature_Control_Library#Latest

• Send format parameter for XML, JSON, JSONP (with extra callback parameter) or Prometheus prom format.

• Defaults to JSON.

XML

• Sample XML request URL:

  http://192.168.2.70/?format=XML

• Sample XML response:

XML
<?xml version=\"1.0\"?>
<xml>
<temperature>
<celcius>0</celcius>
<fahrenheit>32</fahrenheit>
</temperature>
</xml>

• Sample XML response with error:

XML
<?xml version=\"1.0\"?>
<xml>
<temperature>
ERROR
</temperature>
</xml>

JSON

• Sample JSON request URL:

  http://192.168.2.70/?format=JSON

• Sample JSON response:

{
  "temperature": {
    "celcius": 12.50,
    "fahrenheit": 54.50
  }
}

• Sample JSON response with error:

{
  "error": "error"
}

JSONP

• Sample JSONP request URL:

  http://192.168.2.70/?format=JSONP&callback=MyCallback

• Sample JSONP response:

MyCallback({
  "temperature": {
    "celcius": 12.50,
    "fahrenheit": 54.50
  }
});

• Sample JSON response with error:

MyCallback({
  "error": "error"
});

Prometheus

http://192.168.2.70/metric

arduino_temperature_probe 20.00

NOTE: Error state will return a HTTP 500.

NOTE: As per Prometheus best practices, only Celcius is returned.

Config for prometheus.yml:

  - job_name: 'External Ambient Temperature Monitor'
    scrape_interval: 5s
    static_configs:
      - targets: ['192.168.2.70:80']