Portable information terminal apparatus, voltage measurement apparatus, voltage measurement method and program thereof

A voltage measurement apparatus being equipped on a portable information terminal apparatus capable of operating by a battery, comprising:

• a measurement unit for measuring an input direct-current voltage by converting the input direct-current voltage from analog to digital;
• a changeover unit, allowing a plurality of voltages to be applied thereto, for selecting one of the plurality of voltages to output to the measurement unit;
• and
• a voltage value output unit for making the changeover unit select a predetermined one fixed voltage from among the plurality of voltages and making the measurement unit measure the fixed voltage as a reference voltage, generating calculation-use information for the purpose of calculating a voltage value from a measurement result of the measurement unit based on a first measurement value obtained as the measurement result of the fixed voltage and a voltage value of the reference voltage, and calculating, and outputting, a voltage value of the battery by using a second measurement value that is the measurement result of a voltage of the battery and the calculation-use information in a case of making the changeover unit select the voltage of the battery and making the measurement unit measure the voltage of the battery.

A method for making a portable information terminal apparatus, which is equipped with a battery and one or more voltage source for generating a fixed voltage from the battery, measure a voltage, comprising the processes of

• changing over a plurality of voltages at least including respective voltages of the battery and the voltage source, thereby selecting a voltage from among the plurality of voltages, and automatically applying the selected voltages to a measurement unit, which measures an applied voltage by converting the applied voltage from analog to digital and outputs a measurement value according to height of the voltage
• making a fixed voltage generated by a predetermined voltage source automatically selected from among the plurality of voltages, making the measurement unit measure the fixed voltage as a reference voltage and generating calculation-use information for the purpose of calculating a voltage value from a measurement result of the measurement unit based on a first measurement value obtained as the measurement result of the fixed voltage and a voltage value of the reference voltage;
• and
• calculating, and outputting, a voltage value of the battery by using a second measurement value that is the measurement result of a voltage of the battery and the calculation-use information in a case of applying the voltage of the battery to the measurement unit and making the measurement unit measure the applied voltage.

A computer readable storage medium storing a program for making a portable information terminal apparatus, which is equipped with a battery and one or more voltage source for generating a fixed voltage from the battery, carry out functions of

• selecting a voltage to be applied to a measurement unit, which measures an applied voltage by converting the applied voltage from analog to digital and outputs a measurement value according to height of the voltage, from among a plurality of voltages including at least respective voltages of the battery and the voltage source;
• making the function of selecting select a fixed voltage generated by a predetermined voltage source from among the plurality of voltages, making the measurement unit measure the fixed voltage as a reference voltage, and generating calculation-use information for the purpose of calculating a voltage value from a measurement result of the measurement unit based on a first measurement value obtained as the measurement result of the fixed voltage and a voltage value of the reference voltage;
• and
• calculating, and outputting, a voltage value of the battery by using a second measurement value as the measurement result of a voltage of the battery and the calculation-use information in a case of applying the voltage of the battery to the measurement unit and making the measurement unit measure the applied voltage.