Infrared learning device
An infrared (IR) learning device is disclosed. A hardware device of the IR learning device amplifies, shapes, and samples an IR signal to acquire a better digital signal related to the IR signal. A software device of the IR learning device calculates the waveform of the IR signal and the frequency of a carrier wave of the IR signal according to the digital signal related to the IR signal. Accordingly, the IR learning device can learn the IR signal emitted from an external device by the hardware device and the software device.
1. An infrared (IR) learning device, adapted for learning an IR signal emitted from an external device, the IR signal comprising a carrier region and a no-carrier region, the carrier region having a carrier wave, and the IR learning device comprising:
an IR transceiver for receiving the IR signal;
an amplifying and shaping circuit, coupled to the IR transceiver, for amplifying and shaping the IR signal to generate a digital signal related to the IR signal;
a sampling circuit, coupled to the amplifying and shaping circuit, for sampling the digital signal once every period, and performing a level switching record on the digital signal to generate a level switching time while the digital signal having a level conversion; and
a processor, coupled to the sampling circuit and the IR transceiver, for executing the following steps:
determining whether the level switching time is received;
when the level switching time is received, calculating a time interval between the two adjacent level switching times;
accumulating the time interval in a carrier time of the carrier region or in a no-carrier time of the no-carrier region; and
determining whether an end time has been reached, wherein returning to the step of determining whether the level switching time is received if the end time has not been reached; and calculating a waveform of the IR signal and a frequency of the carrier wave of the carrier region according to the carrier time, the no-carrier time and a half-period number of the carrier wave if the end time has been reached.
2. The IR learning device according to claim 1 , wherein when determining that the level switching time is received, the processor re-determines whether the level switching time is received.
3. The IR learning device according to claim 1 , wherein the step of accumulating the time interval in the carrier time of the carrier region or in the no-carrier time of the no-carrier region, further comprises:
determining whether the time interval is a half-period time of the carrier wave;
when the time interval is the half-period time of the carrier wave, accumulating the time interval in a continuous waveform duration time, and adding to a total number of the half-period times by one;
when the time interval is not the half-period time of the carrier wave, determining whether the previous time interval is the half-period time;
when the previous time interval is not the half-period time, accumulating the time interval in a non-waveform duration time, and when the previous time interval is the half-period time, determining whether the continuous waveform duration time indicates a noise;
when the continuous waveform duration time indicates the noise, accumulating the time interval and the continuous waveform duration time in the non-waveform duration time, and when the continuous waveform duration time does not indicate the noise, taking the continuous waveform duration time as the carrier time of the carrier region, taking the non-waveform duration time as the no-carrier time of the no-carrier region, taking the total number as the half-period number, and resetting the continuous waveform duration time, the non-waveform duration time, and the total number; and
after resetting the continuous waveform duration time, the non-waveform duration time, and the total number, accumulating the time interval in the non-waveform duration time.
4. The IR learning device according to claim 3 , wherein when the continuous waveform duration time is less than a predefined time, the processor determines that the continuous waveform duration time indicates the noise.
5. The IR learning device according to claim 3 , wherein when the continuous waveform duration time is more than or equal to a predefined time, the processor determines that the continuous waveform duration time does not indicate the noise.
6. The IR learning device according to claim 1 , wherein the processor takes the carrier time of the carrier region and the no-carrier time of the no-carrier region as the waveform of the IR signal, and takes the half-period number of the carrier wave to calculate the frequency of the carrier wave of the carrier region.
7. The IR learning device according to claim 6 , wherein the carrier time is less than the no-carrier time.
8. The IR learning device according to claim 6 , wherein an upper half period of the carrier wave is equal to a lower half period of the carrier wave.
9. The IR learning device according to claim 1 , wherein the IR transceiver has a transition hole, and the processor controls the IR transceiver transmitting or receiving the IR signal.
10. The IR learning device according to claim 1 , wherein the digital signal is a square-wave signal, and the square-wave signal has at least one duty cycle.