Java sample code for the HTU21D returns a temperature of 0.0

[alexwoolford]

The HTU21DSample.java always returns a temperature of 0.0.

The following dependency was added to pom.xml:

<dependency>
    <groupId>io.mraa.upm</groupId>
    <artifactId>upm_htu21d</artifactId>
    <version>1.2.0</version>
</dependency>

I used the same values for the bus (1) and the I2C address (0x40; decimal value of 64) that worked in Python. Here's a snippet of Java where I'm trying to read the temperature:

upm_htu21d.HTU21D sensor = new upm_htu21d.HTU21D(1, 0x40);
logger.info("sensor.getTemperature(): " + sensor.getTemperature());

The Java code returns a temperature of 0.0, where the Python code (linked above) shows the actual temperature. I experimented with different values for the bus and I2C address. Nothing worked.

Am I doing something wrong? Any suggestions for a (Java) workaround?

[jontrulson]

Hi, It looks like the Java example is missing a call to:

sensor.sampleData();

in the loop. This is needed to actually read updated data from the device...

[alexwoolford]

Thanks so much, @jontrulson . That worked perfectly! I really appreciate your help.

[stefan-andritoiu]

Yes, sorry about that. Fixed and restructured the Java example after the Python one https://github.com/intel-iot-devkit/upm/pull/562/commits/29e1489e40b8b8c5bcd0756725ae06eb9bf772d5

[Propanu]

Merged to master. Thanks!