Firm alarm device having two processors

A fire alarm device, comprising:

• a first light source, configured to emit light of first wavelength;
• a second light source, configured to emit light of second wavelength, which is different from the light of first wavelength;
• a light sensor, configured to detect the light of first wavelength and the light of second wavelength, and respectively generate a first detection signal and a second detection signal;
• a first processor, configured to identify whether to generate a wakeup signal according to a standby intensity variation of the first detection signal;
• a second processor, connected to the first processor to receive the wakeup signal, and configured to identify whether to generate a fire alarm according to a first intensity variation of the first detection signal and a second intensity variation of the second detection signal after being woken up by the wakeup signal;
• and
• a thermal sensor, configured to generate temperature values to be provided to at least one of the first processor and the second processor for being used in the identifying, wherein
• the second processor has an operating capability higher than the first processor.