ارجو ممن له خبرة في microcontroller 8051 ان يساعدني في اجابة هذا السؤال .. وله من الله الاجر والتواب ..امين امين امين.
A microcontroller from the 8051 family is to be used in a roadside device that measures the speed of vehicles in one direction along a road. The speed is measured using two pressure sensors that are placed exactly one metre apart. When a vehicle crosses one of the sensors it activates the sensor. Traffic speed is measured by timing the interval between the activation of one sensor and the activation a short time later of the second sensor as the vehicle moves along the road.
A battery that is charged during daylight by a set of solar cells powers the device.
In order to control the device and upload the speed data, the device has the following controls and connections in addition to the two pressure sensor inputs:-
· A two way serial connection (one way for transmit, one way for receive) to allow the readings of speed to be uploaded for analysis to a central computer.
· A keypad with 16 keys.
· 4 status lights that are used when the device is being set up or readings are being uploaded.
The microcontroller's program will require 4050 bytes and the device must store the speeds of 300 vehicles (each vehicle's speed occupying one byte of memory) before the data is uploaded.
About 50 of these devices are to be made and the physical size of the device means that there is no room for any external memory chips or other external peripheral devices.
a) Explain how the microcontroller's input and output requirements can be satisfied using only two 8-bit ports (assuming the bits in these ports can be used individually.)
B) Explain the technical requirements of a suitable microcontroller for the device.
c) From a technical viewpoint more than one suitable microcontroller has been identified. Apart from cost, write down TWO other considerations that might be used to decide which particular microcontroller to choose.
d) List TWO of the aids that might be used to assist in the development of the microcontroller's software and give a brief description of how they are used.
e) Measuring a vehicle's speed requires the microcontroller to measure the time interval between the signals produced by the pressure sensors.
i) List two ways in which measurement of the time interval might be achieved by the microcontroller.