Hello,

 

I'm testing the weather station with PHP.

 

For WeatherStationWebsite.php I use:

 

<?php

 

require_once('Tinkerforge/IPConnection.php');

require_once('Tinkerforge/BrickletAmbientLight.php');

require_once('Tinkerforge/BrickletHumidity.php');

require_once('Tinkerforge/BrickletBarometer.php');

 

use Tinkerforge\IPConnection;

use Tinkerforge\BrickletAmbientLight;

use Tinkerforge\BrickletHumidity;

use Tinkerforge\BrickletBarometer;

 

$ipcon = new IPConnection();

$brickletAmbientLight = new BrickletAmbientLight("enG", $ipcon);

$brickletHumidity = new BrickletHumidity("eFY", $ipcon);

$brickletBarometer = new BrickletBarometer("eUy", $ipcon);

 

$ipcon->connect("localhost", 4223);

 

$illuminance = $brickletAmbientLight->getIlluminance()/10.0;

$humidity = $brickletHumidity->getHumidity()/10.0;

$air_pressure = $brickletBarometer->getAirPressure()/1000.0;

$temperature = $brickletBarometer->getChipTemperature()/100.0;

 

$response = array (

    "illuminance"  => "Illuminance: $illuminance Lux",

    "humidity"    => "Humidity: $humidity %RH",

    "air_pressure" => "Air Pressure: $air_pressure mbar",

    "temperature"  => "Temperature: $temperature °C",

);

 

print_r(json_encode($response));

 

?>

 

But the result is:

 

{"illuminance":"Illuminance: 1.7 Lux","humidity":"Humidity: 68.6 %RH","air_pressure":"Air Pressure: 1001.318 mbar","temperature":null}

 

What is the correct code to retrieve the temperature from the barometer bricklet?

 

 

Is the divide by 100 the problem? What does it produce if you don't divide at all?

I've changed the number into 10.0, 100.0, 1000.0 and 10000.0, but it all gave the same result, then I've removed the division altogether but the result stays on "null".

 

 

"null" means probably that the object "null" is returned, not the integer 0. Are the PHP Bindings up to date?

PHP Version 5.4.4-14+deb7u2

 

BCMath support enabled

 

include_path .:/usr/share/php:/usr/share/pear

 

Recent download: pear install Tinkerforge.tgz

 

And may I add that WeatherStation.php does work and gives me a correct temperature.

 

But I cannot get a temperature with WeatherStationWebsite.php.

If you print $temperature, is that also "null"?

 

Your PHP seems to evaluate "Temperature: $temperature °C" as null. I am not sure why that is. Perhaps you can try to change the string bit for bit, to find what excatly the reason is!

It seems that the ° in front of the C causes the problem.

 

By omitting the ° I get a response: {"illuminance":"Illuminance: 838.1 Lux","humidity":"Humidity: 61 %RH","air_pressure":"Air Pressure: 1013.163 mbar","temperature":"Temperature: 20.46 C"}

 

Adding a ° gives always a null no mater where it is put.

 

Is ° a not accepted character in PHP?

 

That seems to be a string encoding problem. I just tested it on my PC, here the strings seem to be encoded as utf-8.

 

You probably have to enable utf-8 encoding in your php.ini: http://stackoverflow.com/questions/1605760/how-to-best-configure-php-to-handle-a-utf-8-website

utf-8 encoding wasn't the problem.

 

I fixed it as follows:

 

Changed:  "temperature"  => "Temperature: $temperature °C"

 

To:      "temperature"  => "Temperature: $temperature &degC"

 

Or:      "temperature"  => "Temperature: $temperature &#176C"

 

So the °C was changed to &decC or to &#176C

 

This gives the correct response:  Temperature: 18.83 °C

I changed the example to use ° to make it less error prone.