A highly precise simple A/D conversion circuit and its method based on MSP430

Abstract

The invention relates to a high-precision simple A / D converting circuit and a method based on MSP430. The invention adopts the P2.0 port of the MSP430 to be externally connected with a resistor and a capacitor which are serially connected; the other end of the resistor is connected with the P2.3 port of the MSP430, the other end of the capacitor is connected to the power supply ground. An analog signal is connected to the P2.4 pin of MSP430F1121 to form a sigma-delta resembling type single-slope A / D converter. The conversion method is realized by that a half of the total count value N / 2 is loaded at first, and whether the output of a comparator is high level is determined, if yes, the P2.0 outputs low level; if not, the P2.0 outputs high level; the count value of the high level adds 1, the total count value N / 2 deducts 1, whether the total count value N / 2 is 0 is judged, if not, then the step is skipped previous, if yes, the P2.3 and the P2.4 pins are exchanged internally, and then the measurement sub-program is over. The invention solves the problem that the over-sampling sigma-delta conversion is applied due to the characteristic of high resolution, but the over-sampling sigma-delta conversion has complex structure, large volume, and hard operation. The invention achieves the effects that the conversion method is simple, the circuit structure is simplified, the volume is small, the cost is low, and the method can be easily implemented.

Description

technical field [0001] The invention relates to an A / D conversion circuit and method, in particular to a high-precision and simple A / D conversion circuit and method based on MSP430. Background technique [0002] Before the present invention, the most commonly used method of A / D conversion is the successive approximation method (SAR), and the conversion time is fixed and fast is its biggest feature, but its defective is also obvious, and promptly resolution is low, is difficult to improve; Type A / D conversion has strong anti-interference ability, but the conversion time is long, and the practical application is limited; oversampling Σ-ΔA / D conversion is applied due to its high resolution, but it has complex structure, Large size, difficult operation defects. Contents of the invention [0003] The purpose of the present invention is just to overcome above-mentioned defect, utilizes MSP430 one-chip computer to externally connect a resistor and a capacitor to form a high-prec...

AI Technical Summary

Problems solved by technology

[0002] Before the present invention, the most commonly used method of A / D conversion is the successive approximation method (SAR), and the conversion time is fixed and fast is its biggest feature, but its defective is also obvious, and promptly resolution is low, is difficult to improve; Type A / D conversion has strong anti-interference ability, but the conversion time is long, and the practical application is limited; oversampling Σ-ΔA / D conversion is applied due to its high resolution, but it has complex structure, Large size, difficult to operate defects

Images