2-Way Multiplexed LCD Drive and Low Cost A/D Converter Using V/F Techniques with COP8 Microcontrollers
This application note is intended to show a general solution for implementing a low cost A/D and a 2-way multiplexed LCD drive using National Semiconductor‘s COP840C 8-bit microcontroller. The implementation is demonstrated by means of a digital personal scale. Details and function of the weight sensor itself are not covered in this note. Also the algorithms used to calculate the weight from the measured frequency are not included, as they are too specific and depend on the kind of sensor used.
Typical Applications
- Weighing scales
- Sensors with voltage output
- Capacitive or resistive sensors
- All kinds of measuring equipment
- Automotive test and control systems
Features
2-way multiplexed LCD drive capability up to 30 segments (4 digit and 2 dot points)- Precision frequency measurement
- Low current consumption
- Current saving HALT mode
- Additional computing power for application specific tasks
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