Latest Raspberry Pi Projects
In most of the manufacturing industries, it is required to rotate DC/AC motor forward and reverse alternatively for desired time. First motor rotates forward (clockwise) for some time (say few minutes or even seconds). Then it stops for some time. Again it rotates reverse (anticlockwise) for some time and stops. This process continues. For example, in automated bottle filling plant, the bottles are moving on conveyor belt. When it comes under filler, the filler comes down (that means motor attached with mechanism rotates forward) then it fills the bottle (that means motor stops) again it goes up (motor rotates reverse) and stops until next bottle arrives. For moving filler up and down the time of rotating motor forward and reverse is calibrated and fixed. Also the motor stop time is calibrated based on time required to fill the bottle and the next bottle arrives.
Here the given project demonstrates one time programmable password system using micro controller AT89C51. The system has default password initially that can be changed only once. User can set his own 5 digit password once. Afterword password set button is disabled. User has to enter correct password to lock or unlock the system. Also user gets only three attempts to enter correct password. If he enters wrong password thrice, the complete system hangs. No furthur operation is possible. The only way is to press master reset
The GPS receiver is used to get accurate geographical location by receiving information from satellites. It receives information from satellites and gives location information in terms of latitude and longitude. It gives latitude and longitudes with accuracy of degree-minute-second. Using this latitude and longitude co-ordinates one can easily trace out the location on entire globe. The GPS receivers have enormous applications.
The GPS receiver gives output serially in form of strings with NMEA 0183 protocol. These strings are received serially by host computer or host processor/controller for display or to take any decision or action. The following figure shows the output of GPS receiver on hyper terminal of desktop computer.