Infrared decoding method based on analog capture

Abstract

The invention relates to the technical field of infrared decoding, in particular to an infrared decoding method based on analog capture, which comprises the following steps: setting the priority of external interruption of a single chip microcomputer to be higher than that of a timer, and setting the external interruption to be triggered by a rising edge; initializing a timer for generating interruption in microsecond at the time t, and initializing a counting variable tick for counting the interruption times generated by the timer; after external interruption is generated, judging whether thetriggering mode is a falling edge or a rising edge, and further reading a counting variable value tick of the timer or starting the timer; judging whether the counting variable value tick is greaterthan or equal to a value obtained by a first preset formula or not, and judging whether a lead code is received or not; further judging whether the counting variable value tick is greater than or equal to a value obtained by a second preset formula or not after the lead code is received, and obtaining data bit1 or data bit0; and negating the triggering mode of the external interrupt, and quittingthe interrupt. The decoding method can be suitable for the single-chip microcomputer which is relatively low in price, and the product cost is reduced.

Description

technical field [0001] The invention relates to the technical field of infrared decoding, in particular to an infrared decoding method based on analog capture. Background technique [0002] At present, most of the infrared remote controls used in electronic products use NEC codes. Such as figure 1 One frame of the NEC code shown (usually the data sent by pressing a button on the remote control) consists of a boot code, an address code, and a data code. [0003] The NEC protocol defines the boot code, data 1, and data 0 as follows figure 2 As shown, through comparative analysis, it can be found that the difference between data 1 and data 0 lies in the high level pulse width. Therefore, the principle of single-chip infrared decoding is generally to use the capture function of the timer to measure the pulse width of the high level, and then judge whether it is data 1 or data 0. [0004] Timer capture principle: enable the capture function and set it to trigger an interrupt...

AI Technical Summary

Problems solved by technology

[0005] But many low-end single-chip microcomputers do not have the capture function, for example, some low-end single-chip microcomputers with 51 cores

If the traditional external interrupt plus delay method is used, it will affect the real-time performance

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