TMP1101 User Guide

Getting Started

Welcome to the TMP1101 user guide! In order to get started, make sure you have the following hardware on hand:

• TMP1101 - 4x Thermocouple Phidget
• VINT Hub
• Phidget cable
• USB cable and computer
• Thermocouple

Next, you will need to connect the pieces:

1. Connect the thermocouple to one of the inputs on the TMP1101. The datasheet or product page for the thermocouple should tell you which wire is positive and which is negative.
2. Connect the TMP1101 to the VINT Hub using the Phidget cable.
3. Connect the VINT Hub to your computer with a USB cable.

Now that you have everything together, let's start using the TMP1101!

Using the TMP1101

Phidget Control Panel

In order to demonstrate the functionality of the TMP1101, the Phidget Control Panel running on a Windows machine will be used.

The Phidget Control Panel is available for use on both macOS and Windows machines.

Windows

To open the Phidget Control Panel on Windows, find the icon in the taskbar. If it is not there, open up the start menu and search for Phidget Control Panel

macOS

To open the Phidget Control Panel on macOS, open Finder and navigate to the Phidget Control Panel in the Applications list. Double click on the icon to bring up the Phidget Control Panel.

For more information, take a look at the getting started guide for your operating system:

• Getting started with Windows
• Getting started with macOS

Linux users can follow the getting started with Linux guide and continue reading here for more information about the TMP1101.

First Look

After plugging the TMP1101 into your computer and opening the Phidget Control Panel, you will see something like this:

The Phidget Control Panel will list all connected Phidgets and associated objects, as well as the following information:

• Serial number: allows you to differentiate between similar Phidgets.
• Channel: allows you to differentiate between similar objects on a Phidget.
• Version number: corresponds to the firmware version your Phidget is running. If your Phidget is listed in red, your firmware is out of date. Update the firmware by double-clicking the entry.

The Phidget Control Panel can also be used to test your device. Double-clicking on an object will open an example.

Temperature Sensor (Thermocouple)

Double-click on the Temperature Sensor object, labelled Thermocouple Input, in order to run the example:

General information about the selected object will be displayed at the top of the window. You can also experiment with the following functionality:

• Modify the change trigger and/or data interval value by dragging the sliders. For more information on these settings, see the data interval/change trigger page.
• Select your thermocouple type from the Thermocouple Type drop-down menu.
• The measured temperature will be updated next to the Temperature label. Touch the thermocouple wire with your hands to see the temperature increase. If the temperature decreases when it should be increasing, you may have the wires plugged in incorrectly.

Temperature Sensor (IC)

Double-click on the Temperature Sensor object , labelled Temperature Sensor (IC), in order to run the example:

General information about the selected object will be displayed at the top of the window. You can also experiment with the following functionality:

• Modify the change trigger and/or data interval value by dragging the sliders. For more information on these settings, see the data interval/change trigger page.
• The measured temperature can be seen next to the Temperature label. Cover the board with your hands to see the temperature quickly rise.

Voltage Input

Double-click on the Voltage Input object in order to run the example:

General information about the selected object will be displayed at the top of the window. You can also experiment with the following functionality:

• Modify the change trigger and/or data interval value by dragging the sliders. For more information on these settings, see the data interval/change trigger page.

Finding The Addressing Information

Before you can access the device in your own code, and from our examples, you'll need to take note of the addressing parameters for your Phidget. These will indicate how the Phidget is physically connected to your application. For simplicity, these parameters can be found by clicking the button at the top of the Control Panel example for that Phidget.

In the Addressing Information window, the section above the line displays information you will need to connect to your Phidget from any application. In particular, note the Channel Class field as this will be the API you will need to use with your Phidget, and the type of example you should use to get started with it. The section below the line provides information about the network the Phidget is connected on if it is attached remotely. Keep track of these parameters moving forward, as you will need them once you start running our examples or your own code.

Using Your Own Program

You are now ready to start writing your own code for the device. The best way to do that is to start from our Code Samples.

Select your programming language of choice from the drop-down list to get an example for your device. You can use the options provided to further customize the example to best suit your needs.

Once you have your example, you will need to follow the instructions on the page for your programming language to get it running. To find these instructions, select your programming language from the Programming Languages page.

Technical Details

Cold Junction Compensation and Self-heating

Thermocouples consist of two junctions, one where the thermocouple meets the Phidget and one where the two wires are welded together at the sensing end of the device. In simplified terms, a thermocouple works by detecting the temperature difference between these two junctions. As such, in order to measure the temperature at the sensing end we need to know the temperature where the thermocouple connects to the Phidget. To do so, there is an ambient temperature sensor on the board.

An important thing to note is that the ambient temperature sensor measures the temperature of the board and the air around it, though not specifically at the junction. Generally you can assume they are nearly the same temperature, however as the electronics heat up by being powered on there can be some small error introduced. This is exacerbated by having the board in an enclosed space where normal airflow is restricted thereby increasing the effect of self-heating. As a result we recommend that the board be left in as open and well ventilated/cooled a place as possible to minimize this error source.

For more information on thermocouples, check out the Thermocouple Primer.

50Hz/60Hz Filtering

One of the most common sources of electrical noise in a system is 50Hz or 60Hz hum from local power grid. For firmware versions 107 and later for this Phidget, we have added a filter to compensate for 50Hz or 60Hz hum in your system. This means you can worry less about this problem in your application.

Without filtering, sensors in electrically noisy environments could see a repeating drift of tens of degrees, as noise from power lines finds its way into the system. The timing of this drift could vary, depending on how the samples from the sensor lined up with the noise from the power lines.

To combat this issue, all thermocouple temperature and voltage measurements on this device are now passed through a 100ms moving average filter, with samples taken at specific intervals designed to cancel out frequencies of 50Hz and 60Hz (the most common power grid frequencies). The filtering on this Phidget will reduce the effect of power line noise by 95% or more, becoming more effective as the power line frequency approaches 50Hz or 60Hz exactly.

All samples from the sensor will be subject to filtering. When used with data intervals longer than 100ms, the sensor will measure the thermocouple(s) for 100ms to perform a measurement. When using data intervals less than 100ms, your application will see the effects of the latest measurements as they pass through the filter.

What to do Next

• Programming Languages - Find your preferred programming language here and learn how to write your own code with Phidgets!
• Phidget Programming Basics - Once you have set up Phidgets to work with your programming environment, we recommend you read our page on to learn the fundamentals of programming with Phidgets.