Now a days we have been hearing about death of children being left inside hot cars. None of the vehicles driven today, old or new, have any way of intimating the drivers that either the car interior is getting hot, left a kid in the car or both. Hence this VeTAS project will enable the drivers to get intimation when things are going wrong.
As these are basically 'proof of concept' projects, I am aiming to keep it simple with provisions for extensions and improvements. I will make it as modular as possible so that extending it will be easier in future. The following will describe the design and function of this system.
Hardware: This system utilizes all the components of the STM32 kit, namely the base board, the sensor expansion board, the Wi-Fi expansion board and the Bluetooth LE expansion board. Additionally I plan to use a Cellular Shield board to communicate wirelessly with outside world. These will be used as follows:
- The base STM32-NUCLEO-L476RG board forms the essential part of the system as this contains the firmware of the system.
- The temperature and humidity sensor of the ISK01A2 sensor expansion board will be used for monitoring the vehicle inside environment.
- The IDB05A1 BT EL board will be used essentially to initial setup of the system from a mobile app on a smartphone. Both iOS & Android, possibly Windows Mobile also, will be supported.
- The IDW04A1 Wi-Fi board will be used to connect to nearby hotspots to transfer data to cloud and / or send email and / or messages (SMS / Push Notifications) to intimate the alerts to the user / driver.
- The Cellular Shield board will be used to connect cloud and to send alert messages when the Wi-Fi connection is not available. This will be taken up at the end as an optional unit. The complexity of cellular communications availability is one of the major hurdle in working this out.
The mobile app will be used to perform initial setup, display live or history data and to manage cloud component. Currently planning to develop using Xamarin Technology for this cross-platform app. Initially Microsoft Azure will be used for cloud component.
In the initial setup the following settings will be set in the devices,
- Wi-Fi connection details
- Device Id
- Temperature Unit (C or F) and Threshold Temperature
- Mobile number and email address for alert messages
- Register the device to the Azure IoT Hub and get the device connection string for connecting the device to cloud.
During setup the data will be transmitted every 5 seconds. Once the setup is completed and ensured the data streaming, the data will be streamed every 15 minutes only to save on data transmission fees and battery. But if an alert occurs, the data will be transmitted every 5 seconds for 15 minutes or till the user takes some action, which ever occurs first.
Attached herewith is the Block Diagram of the system.
I am in receipt of the sponsored kit and will blog about its setup soon.
VeTAS - Block Diagram.pdf 331.7 KB