Patent Publication Number: US-2013241739-A1

Title: Indicator light control device

Description:
BACKGROUND 
     1. Technical Field 
     The disclosure generally relates to indicator light control devices, and particularly to an indicator light control device for indicating an operational status of a personal computer (PC). 
     2. Description of the Related Art 
     In a PC, an indicator light is usually mounted on a front panel of the PC to indicate an operational status of the PC. For example, when the indicator light is on, the PC is in an S0 state, which means a central processing unit (CPU) of the PC is fully operating and all of devices of the PC are powering up and down as needed. When the indicator light is flickering, the PC is in an S3 state, which means the CPU has no power, a random access memory of the PC is in slow refresh, and a power supply of the PC is generally in a reduced power mode (for example, the power supply not supplying much power and operating in a lower power efficiency mode). When the indicator light is off, the PC is in an S5 state, which means hardware of the PC is completely off, the operating system of the PC has shut down, and nothing has been saved. Apparently, certain parameters of the indicator light, such as its luminance, color, or flicker frequency, are unchangeable, and cannot be adjusted by users according to their needs. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. 
         FIG. 1  is a block diagram of an indicator light control device, according to an exemplary embodiment. 
         FIG. 2  is a circuit diagram of the indicator light control device shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a block diagram of an indicator light control device  100 , according to an exemplary embodiment. The indicator light control device  100  includes a motherboard  10 , an indicator control board  30 , and a status indicator unit  50 . The motherboard  10 , the indicator control board  30 , and the status indicator unit  50  are electronically connected in series. The motherboard  10  is mounted in an electronic device (not shown), such as a personal computer, for example. The motherboard  10  outputs a first control signal and a second control signal to the indicator control board  30  according to an operational status of the electronic device. The indicator control board  30  determines the operational status of the electronic device according to the first and second control signals. The indicator control board  30  further controls operation of the status indicator unit  50  according to the determined operational status of the electronic device. 
     Referring to  FIG. 2 , the motherboard  10  includes a chipset  11  and an embed controller (EC)  13 . The chipset  11  is electronically connected to the EC  13  through a low pin count (LPC) bus. The chipset  11  controls the EC  13  to output the first and second control signals according to the operational status of the electronic device. The EC  13  includes a group of general purpose input output (GPIO) pins GPIO 1 , GPIO 2 . The GPIO pin GPIO 1  is a first control signal output pin and can output the first control signal under the control of the chipset  11 . The GPIO pin GPIO 2  is a second control signal output pin and can output the second control signal under the control of the chipset  11 . 
     In detail, when the electronic device is in a first state (e.g., an S0 state), the GPIO pins GPIO 1 , GPIO 2  respectively output a high voltage signal (e.g., logic 1) and a low voltage signal (e.g., logic 0) under the control of the chipset  11 , i.e., the first and second control signals are a high voltage signal and a low voltage signal, respectively. When the electronic device is in a second state (e.g., an S3 state), the GPIO pins GPIO 1 , GPIO 2  respectively output a high voltage signal (e.g., logic 1) and a pulse signal under the control of the chipset  11 , i.e., the first and second control signals are a high voltage signal and a pulse signal, respectively. When the electronic device is in a third state (e.g., an S5 state), the GPIO pins GPIO 1 , GPIO 2  respectively output a low voltage signal (e.g., logic 0) and a high voltage signal (e.g., logic 1) under the control of the chipset  11 , i.e., the first and second control signals are a low voltage signal and a high voltage signal, respectively. 
     The indicator control board  30  includes a microcontroller (MCU)  31  and a signal processing circuit  33 . The MCU  31  includes a group of GPIO pins GPIO 3 -GPIO 8 . The GPIO pin GPIO 3  is a first control signal receiving pin. The GPIO pin GPIO 3  is electronically connected to the GPIO pin GPIO  1  and receives the first control signal from the EC  13 . The GPIO pin GPIO 4  is a second control signal receiving pin. The GPIO pin GPIO 4  is electronically connected to the GPIO pin GPIO 2  and receives the second control signal from the EC  13 . The GPIO pin GPIO 5  is a feedback pin and is electronically connected to the GPIO pin GPIO 4  through the signal processing circuit  33 . The GPIO pins GPIO 6 -GPIO 8  are control pins and are all electronically connected to the status indicator unit  50 . 
     The signal processing circuit  33  includes a first resistor R 1 , a second resistor R 2 , a capacitor C, and a metal-oxide-semiconductor field-effect transistor (MOSFET) Q. A first terminal of the first resistor R 1  is connected to the GPIO pin GPIO 4 . A second terminal of the first resistor R 1  is connected to a gate of the MOSFET Q. A first terminal of the capacitor C is connected between the first resistor R 1  and the gate of the MOSFET Q. A second terminal of the capacitor C is connected to ground. A source of the MOSFET Q is connected to ground. A drain of the MOSFET Q is connected to a power supply VCC through the second resistor R 2 . The drain of the MOSFET Q is also connected the GPIO pin GPIO 5 . 
     The signal processing circuit  33  processes the second control signal received by the GPIO pin GPIO 4  of the MCU  31  and outputs the processed second control signal to the feedback pin (i.e., GPIO pin GPIO 5 ). In detail, when the GPIO pin GPIO 4  receives a low voltage signal, the low voltage signal is output to the gate of the MOSFET Q, and the MOSFET Q is turned off. In this way, the GPIO pin GPIO 5  of the MCU  31  is connected to the power supply VCC through the second resistor R 2  to obtain a high voltage signal. When the GPIO pin GPIO 4  receives a high voltage signal, the high voltage signal is output to the gate of the MOSFET Q, and the MOSFET Q is turned on. In this way, the GPIO pin GPIO 5  of the MCU  31  is connected to the ground through the MOSFET Q to obtain a low voltage signal. When the GPIO pin GPIO 4  receives a pulse signal, the first resistor R 1  and the capacitor C will form an integral circuit to transform the pulse signal into a high voltage signal. The transformed high voltage signal is further output to the gate of the MOSFET Q, and the MOSFET Q is turned on. In this way, the GPIO pin GPIO 5  of the MCU  31  is connected to the ground through the MOSFET Q to obtain a low voltage signal. 
     Thus, the MCU  31  can determine an operational status of the electronic device through the GPIO pins GPIO 3 , GPIO 5 . For example, when the GPIO pins GPIO 3 , GPIO 5  are both high voltage signals, the MCU  31  determines the electronic device being in the first state. When the GPIO pins GPIO 3 , GPIO 5  are a high voltage signal and a low voltage signal, respectively, the MCU  31  determines the electronic device being in the second state. When the GPIO pins GPIO 3 , GPIO 5  are both low voltage signals, the MCU  31  determines the electronic device being in the third state. 
     The status indicator unit  50  includes a group of light emitting diodes (LEDs) D 1 -D 3 . A cathode of each LED is electronically connected to a corresponding control pin through a resistor. An anode of each LED is electronically connected to the power supply VCC. For example, the cathode of the LED D 1  is electronically connected to the control pin (i.e., GPIO pin GPIO 6 ) through a resistor R 3 . The anode of the LED D 1  is electronically connected to the power supply VCC. 
     The GPIO pins GPIO 6 -GPIO 8  can control the LEDs D 1 -D 3  to emit light with different colors to correspond to different states of the electronic device. For example, when the MCU  31  determines the electronic device being in the first state through the GPIO pins GPIO 3 , GPIO 5 , the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a low voltage signal, a high voltage signal, and a high voltage signal, respectively. In this way, the LED D 1  is turned on and emits light with a first color (e.g., red light), and the LEDs D 2 , D 3  are turned off, which indicates that the electronic device is in the first state. When the MCU  31  determines the electronic device being in the second state through the GPIO pins GPIO 3 , GPIO 5 , the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a high voltage signal, a low voltage signal, and a high voltage signal, respectively. In this way, the LED D 2  is turned on and emits light with a second color (e.g., green light), and the LEDs D 1 , D 3  are turned off, which indicates that the electronic device is in the second state. When the MCU  31  determines the electronic device being in the third state through the GPIO pins GPIO 3 , GPIO 5 , the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a high voltage signal, a high voltage signal, and a low voltage signal, respectively. In this way, the LED D 2  is turned on and emits light with a third color (e.g., blue light), and the LEDs D 1 , D 2  are turned off, which indicates that the electronic device is in the third state. 
     In use, when the GPIO pins GPIO 1 , GPIO 2  output a high voltage signal and a low voltage signal, respectively, under the control of the chipset  11 , the GPIO pins GPIO 3 , GPIO 5  both obtain a high voltage signal. Thus, the MCU  31  determines the electronic device being in the first state. Then, the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a low voltage signal, a high voltage signal, and a high voltage signal, respectively. In this way, the LED D 1  is turned on and emits light with the first color, and the LEDs D 2 , D 3  are turned off, which indicates the electronic device is in the first state. 
     When the GPIO pins GPIO 1 , GPIO 2  output a high voltage signal and a pulse signal, respectively, under the control of the chipset  11 , the GPIO pins GPIO 3 , GPIO 5  respectively obtain a high voltage signal and a low voltage signal. Thus, the MCU  31  determines the electronic device being in the second state. Then, the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a high voltage signal, a low voltage signal, and a high voltage signal, respectively. In this way, the LED D 2  is turned on and emits light with the second color, and the LEDs D 1 , D 3  are turned off, which indicates the electronic device is in the second state. 
     When the GPIO pins GPIO 1 , GPIO 2  output a low voltage signal and a high voltage signal, respectively, under the control of the chipset  11 , the GPIO pins GPIO 3 , GPIO 5  both obtain a low voltage signal. Thus, the MCU  31  determines the electronic device being in the third state. Then, the MCU  31  controls the GPIO pins GPIO 6 -GPIO 8  output a high voltage signal, a high voltage signal, and a low voltage signal, respectively. In this way, the LED D 3  is turned on and emits light with the third color, and the LEDs D 1 , D 2  are turned off, which indicates the electronic device is in the third state. 
     In summary, in the indicator light control device of this embodiment of the disclosure, the MCU  31  can determine the operational status of the electronic device through the GPIO pins GPIO 3 , GPIO 5 , and can further control the operation of the status indicator unit  50  to indicate users through the GPIO pins GPIO 6 -GPIO 8 . The indicator light control device has a simple circuit structure, and can adjust certain parameters of the status indicator unit  50  according to the needs of the user, such as color, which is convenient for users to identify an operational status of the electronic device. 
     In the present specification and claims, the word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. Further, the word “comprising” does not exclude the presence of elements or steps other than those listed. 
     It is to be also understood that even though numerous characteristics and advantages of exemplary embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of arrangement of parts within the principles of this disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.