 Good morning and welcome to this tutorial video from STA Microelectronics. I am Andrei Vitale, sensor ecosystem manager in the Internet of Things Excellence Center in Santa Clara. Today I'm going to use the Sensor Time Development Kit. We will see how to use the environmental MEMS sensors and verify their performance. MEMS stands for Micro-Electromechanical Systems. The environmental sensors are the barometer to sense the ambient pressure and the hygrometer to sense the ambient relative humidity and temperature. We will also have a quick look at the digital MEMS microphone, which can be used to sense ambient sounds. A short introduction to the Sensor Tile. The Sensor Tile is a reference design, an evaluation tool and a development platform. The Sensor Tile is a tiny, square-shaped module. It is only 13.5 x 13.5 mm. This module packs a powerful microcontroller, a Bluetooth low-energy radio network processor, motion sensors, accelerometer and gyroscope, environmental sensors, magnetometer and barometer, and a digital microphone. The Sensor Tile is part of the Sensor Tile Kit. The Sensor Tile Kit includes two different motherboards that can extend its capabilities. The Sensor Tile Cradleboard and the Sensor Tile Cradle Expansion Board. If you want to learn how to assemble the Sensor Tile, search the Unboxing the Sensor Tile video on YouTube. Once you have assembled your Sensor Tile, you can connect it to your smartphone. You just need to download and install the ST BlueMS app from the iTunes or the Android Store. When you are ready, power up your Sensor Tile and run the ST BlueMS app on your smartphone. Connect the Sensor Tile to the ST BlueMS app. Power up the device and wait until you see the orange LED blinking. Then launch the ST BlueMS app. Push on the Start Discovering button. And you will see the device name on the list. In this case, we are running the old Mems 1 firmware version 3.2.0. Select the device and you will be connected. Log the ambient pressure, relative humidity and temperature. In this screen, you can see the ambient temperature, pressure and relative humidity. If the Sensor Tile is assembled on its cradleboard, there are two ambient temperatures. The first one is from the humidity sensor, the thermometer. The second one is from the pressure sensor, the barometer. Press the Share icon on the top right corner of the screen. A pop-up menu will appear. Select Start Logging. You can now blow some hot and humid air on the device to see variations in temperature and humidity. Or you can move the device up and down to see variations in the ambient pressure. Press again the Share icon and then select Stop Logging. Plot and log data in real time. Press the Plot data icon on the bottom of the screen. Press Select Feature and scroll until you find the parameter of interest. Humidity. Select. Scroll to select the time scale for the plot. Select. You will see the data in real time. Press the Share icon on the top right corner of the screen. Select Start Logging. Make some change in the parameter by blowing some hot and humid air on the device. When you're done, press again the Share icon and select Stop Logging. The app will prepare an email with several attachments. If you have selected an environmental parameter for the plot, you will get the log for all the environmental parameters. Humidity, pressure and temperature. Plot sound pressure level and stream voice over Bluetooth low energy. Press the Plot data icon on the bottom of the screen. Press Select Feature and scroll to the end. Let's select Microphone level. And again select for the time scale of the plot. You will see the sound pressure level in DD. If I stay silent, the level will drop. And as soon as I speak, the level will raise again. Now let's press the More icon and select Blue Voice. Blue Voice is a function which transmits voice over the Bluetooth low energy line. This is not easy to do as Bluetooth low energy has no dedicated profile with high throughput and low latency as the classic Bluetooth. It must be emulated. To hear your voice on the smartphone speaker, be sure that it is not in vibration only mode. Be aware that if the microphone or the sensor tile can capture the sound from the smartphone speaker, the high pitch lasts in effect due to audio feedback and happen. Performance of the barometer for altitude estimation. Let's have a closer look to the performance of the barometer. Sound and pressure is related to many factors. One of them is the altitude. Let's then perform an experiment. Turn on the sensor tile and connect it to the ST Blue MS app. Press the Share icon and start logging the environmental data. To verify the sensitivity to the altitude, repeat the following sequence at least two times. Move the sensor tile up by few inches and keep it at that level for few seconds. Then move the sensor tile back to the original level and keep it there for few seconds. When you're done, press the Share icon again and stop logging. Send the email with its attachments to yourself. The attachments are in CSV format, comma separated values. You can read them using a simple text editor or you can use a software tool such as Matlab or Excel. In this case I've used Excel. I copied the relevant columns in my Excel sheet and I've created two plots. One for the ambient pressure and the other one for the temperature. Do not forget to edit the axis properties to zoom in and see the small variations that can be there. Looking at the ambient pressure, one can easily see that the output changes due to the altitude changes. When the boat was up, the ambient pressure was down. And when the boat was down, the ambient pressure was up. Looking at the temperature, one can see the temperature stability of the output. The sensor tile was warming up, but the output of the parameter was stable. The last portion of the plot shows a pressure spike and temperature increase, which is due to blowing with breath on the sensor. During this tutorial we have seen how to use the sensor tile development kit to use environmental MEMS sensors and verify their performance. I hope you have seen how easy it is to use the sensor tile as an evaluation tool. Thank you for watching. Bye!