This project creates a connected temperature sensor that is used as a thermostat from a TapNLink module. The project uses TapNLink's embedded Java Virtual Machine (JVM) as the application processor. The JVM runs a simple Java program to drive the temperature sensor.

THE THERMOSTAP IN THIS DESIGN CONNECTS DIRECTLY TO 220 VOLT MAINS POWER.

Physical contact with any component of the design can cause electrocution resulting in serious INJURY, or DEATH.

DO NOT reproduce this design without appropriate knowledge of, and protective measures for working with mains power.

Disconnect power before handling the material or manipulating the connections. Ensure that material is properly grounded and isolated. Always work with another adult present in case of an emergency.

Note: Before starting, learn how TapNLink and the associated tools work in this Getting Started.

This project is on Github !

The project has 4 folders:

• app_generated/ThermosTap.apk: Source for the mobile application. It was auto generated by IoTize mobile app build server.
• java/ThermosTap.java: Contains a Java code which will be executed by the JVM.
• iotize_studio/ThermosTap.iotz: IoTize Studio configuration file to configure the TapNLink for the demo.
• doc: Contains a pictures and java code readme file.

The main components used in this project are:

• TapNLink (the communication module), it's here.

The hardware setup

General view of the project

The schematic below contains 3 blocks that can be used to control the temperature:

1. a simple relay that is supposed to start/stop heating.
2. an OT+ (opentherm) interface,
3. a 'pilot wire' that is an interface very popular on the French market (and almost unknown everywhere else).

In the application below, only the 'simple relay' block will be used.

Electrical diagram

In the Java code executed by the JVM, the onCheck() is called periodically (the period is specified in the TapNLinkVar construct). Using this method, we determine the power by evaluating the differences in the pulses counts during the elapsed time.

• for more Java code information, click here !

1. Open the TapNLink configuration project iotize_studio/ThermosTap.iotz with IoTize Studio. For more information about Studio click here.
2. In the IoTize_Studio/Tap section, set User internal JVM to Yes, and set the .java file path java/ThermosTap.java.
3. In IoTize Studio, execute the java build to generate the .bcb file.
4. Configure your TapNLink using IoTize Studio :
   • Setup the connection to your TapNLink
   • Set the IoT Platform (MQTT) settings.
   • Click on the Configure button, and wait until the end of the configuration process.
5. Reboot the TapNLink to apply the new configuration.

• Because this app has not been published on app stores, you have to install it manually. See how this is done here.
• After your circuit is properly connected, and your TapNLink configured, launch the mobile app. The fastest way is to approach your mobile phone (with NFC enabled) to the TapNLink. NFC will launch the app and connect the mobile to the TapNLink automatically.
• With TapNLink you can now monitor the target and current temperatures.

View of the app

You can activate any mode. However, if Auto recovery mode is enabled, then the mode will automatically be reset to AUTO at the start of each time period.

Selecting the mode

The temperatures for each mode is changed from the app using a slider.

The temperature sliders

You can modify the hysteresis to avoid frequent On/Off switching.

Hysteresis slider

For each day, set the type as Work Day or Weekend. This will determine the program that is applied for each day.

Setting the type of day

For each type of day, set the schedule with heating modes (Comfort, Eco, etc.) for each time period.

Programming the Weekend