Digital-to-analogue conversion method based on PWM (pulse width modulation) pin of DSP (digital signal processor)

Abstract

The invention relates to a digital-to-analogue conversion method based on a PWM (pulse width modulation) pin of a DSP (digital signal processor). The PWM pin in the DSP outputs a contact resistor R, a capacitor C is connected between the resistor R and a circuit GND (ground), and a public connecting point of the resistor R and the capacitor C serves as output; a signal requiring digital-to-analogue conversion is compared with a compare register in the DSP by the PWM pin in the DSP so as to obtain a high-frequency pulse waveform corresponding to the signal from the PWM pin, and then a waveform which is very close to the original signal can be obtained through the filter of the pulse waveform. According to the method, the analog of digital signals can be realized on the basis that the hardware cost is not increased nearly, and the complicated algorithm is not needed, and therefore, the danger caused by the online simulation run does not exist.

Description

technical field [0001] The invention relates to a digital-to-analog conversion method realized based on DSP PWM pins, which is used for conveniently viewing the specific waveform of intermediate digital variables. Background technique [0002] In the digital control circuit, many control algorithms are implemented in the digital signal processor (DSP), the input variable is sent to the DSP, and the output variable is obtained after calculation, but in the debugging process of the circuit, it is often necessary to see the intermediate In order to debug whether the algorithm is correct or not, the general DSP programming environment will provide the function of online simulation, and the waveform of the intermediate variable can be viewed from the computer through the connection with the DSP, but this method is used in some high-power operation or the circuit is not compatible with the computer. In the case of the ground, there will be problems, and even lead to dangers such ...

AI Technical Summary

Problems solved by technology

[0002] In the digital control circuit, many control algorithms are implemented in the digital signal processor (DSP), the input variable is sent to the DSP, and the output variable is obtained after calculation, but in the debugging process of the circuit, it is often necessary to see the intermediate In order to debug whether the algorithm is correct or not, the general DSP programming environment will provide the function of online simulation, and the waveform of the intermediate variable can be viewed from the computer through the connection with the DSP, but this method is used in some high-power operation or the circuit is not compatible with the computer. In the case of ground, there will be problems, and even lead to dangers such as bombing

In the case of not connecting to a computer, it is also possible to use a digital-to-analog conversion (DAC) chip to program a variable in the DSP program to an analog value and then observe it through an oscilloscope, but this method requires digital-to-analog conversion outside the DSP chip, thereby increasing the cost

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