This system uses two ARM microcontrollers, specifically the TM4C123GH6PM. One of the microcontrollers performs the function of data acquisition, while the other focusses on data rendering. This system is designed for automotive purposes, where data is collected from several sources. This data is then sent to another controller that uses it to make decisions and run an user display. This transfer of data happens through a CAN bus. CAN stands for Controller Area Network and it is essentially a 2-wire communication protocol.
In the data acquisition end 4 sensors are used – ultrasonic, temperature, pressure and a photocell (LDR). The ultrasonic sensor is to be fitted to the rear of the vehicle. It is similar to a Rear Parking Assist, except that if the distance is too less, not only does the buzzer go on but also the motor (assuming an electric vehicle) will stop.
Temperature sensor measures the cabin temperature and the pressure sensor measures tyre pressure. These data are not used in any particular decision making. They are simply shown on the display.
A photo cell acts as light sensor and if the external ambiance is low it automatically switches on the headlight. This is the basic purpose of the system. The decisions regarding rear distance and light are all taken by the data rendering controller. For example, depending on the brightness of the environment (sensed by the LDR and transmitted by the data acquisition controller) the data rendering controller switches ON/OFF a white LED that represents the headlights.
Conceptually, the data acquisition controller gets the data from the sensors and transmits it to the data rendering controller. The data rendering side then makes both decisions about the motor and the white LED. All these parameters are displayed in a 16×2 LCD display by the data rendering controller, where D- stands for distance, L- stands for light, T- stands for temperature and P- stands for pressure.
This is the ARM and CAN bus based system for Automotive data monitoring. Several enhancements can be made with more sophisticated sensors to monitor several other data. However, this is the fundamental setup.