A Technique for Simultaneous Measurement with a Microcomputer

This paper introduces a method for the simultaneous measurement of a number of physical variables with a microcomputer. Physical variables converted into frequency analogs with the help of controlled oscillators are connected to an input port of a microcomputer with one port-bit per signal. The input port is monitored for a preset time during which a time count is incremented from an initial value of zero at fixed time delays. Whenever a transition in level with any of the frequency signals is detected, a transition word is stored in memory and the corresponding time count is stored in the stack. The values of the variables are computed from the above data using the predetermined values of scale factors. This technique of measurement reduces the measurement time and maintains a preset value of accuracy, independent of the magnitudes of the physical variables to be measured. This method is also economical.