Controller for retractable keyboards
A controller and methods for controlling a retractable keyboard are disclosed. The controller may control and monitor an extend operation of the retractable keyboard using a first pin, and control and monitor a retract operation of the retractable keyboard using a second pin. Open drain signaling may be used on the pins to allow control and monitoring through the same pin. To control and monitor the extend (or retract) operation using a single pin, the controller releases the voltage at the pin to a floating high state to activate the muscle wire to extend (or retract) the keyboard. During the operation, the controller checks the voltage state at the pin. If the voltage at the pin has been pulled to low by the closing of a limit switch, the controller determines that the extend (or retract) operation has completed and in response drives the pin to a low voltage state to deactivate the muscle wire.
1. An apparatus, comprising:
a controller comprising:
a first pin configured to control and monitor an extend operation of a retractable keyboard, wherein the controller is configured to control and monitor the extend operation through a single pin; and
a second pin configured to control and monitor a retract operation of the retractable keyboard, wherein the controller is configured to control and monitor the retract operation through a single pin.
2. The apparatus of claim 1 , wherein the controller is configured to control and monitor through a single pin by determining whether the single pin floats high when not driven by the controller.
3. The apparatus of claim 1 , wherein the controller is configured to perform steps comprising:
driving the second pin to a floating high state to begin the retract operation; and
determining the retract operation is complete by monitoring the second pin.
4. The apparatus of claim 3 , wherein the controller is configured to perform steps comprising determining the retract operation is complete based on a determination that the second pin is in a low voltage state.
5. The apparatus of claim 1 , wherein the controller is configured to perform steps comprising:
driving the first pin to a floating high state to begin the extend operation; and
determining the extend operation is complete by monitoring the first pin.
6. The apparatus of claim 5 , wherein the controller is configured to perform steps further comprising driving the first pin to a low state after determining the extend operation is complete.
7. A method, comprising:
controlling and monitoring, through a first pin of a controller, an extend operation of a retractable keyboard; and
controlling and monitoring, through a second pin of the controller, a retract operation of the retractable keyboard.
8. The method of claim 7 , wherein the controller is configured to control and monitor the extent operation or retract operation through a single pin by determining whether the single pin floats high when not driven by the controller.
9. The method of claim 7 , wherein the controller is configured to perform steps comprising:
driving the second pin to a floating high state to begin the retract operation; and
determining the retract operation is complete by monitoring the second pin.
10. The method of claim 9 , wherein the controller is configured to perform steps further comprising driving the second pin to a low state after determining the retract operation is complete.
11. The method of claim 7 , wherein the controller is configured to perform steps comprising:
driving the first pin to a floating high state to begin the extend operation; and
determining the extend operation is complete by monitoring the first pin.
12. The method of claim 11 , wherein the controller is configured to perform steps further comprising driving the first pin to a low state after determining the extend operation is complete.
13. An apparatus, comprising:
a keyboard;
a first muscle wire coupled to the keyboard and configured to extend the keyboard to a first position to receive user input;
a second muscle wire coupled to the keyboard and configured to retract the keyboard to a second position to store the keyboard in a computer chassis;
a first muscle wire controller coupled to the first muscle wire, comprising:
a first output node controlled to apply a first voltage to the first muscle wire to begin an extend operation;
a first input node for receiving a first control signal to enable or disable output of the first voltage to the first output node; and
a first limit switch coupled to the first input and to a ground;
a second muscle wire controller coupled to the second muscle wire, comprising:
a second output node controlled to apply a second voltage to the second muscle wire to begin an retract operation;
a second input node for receiving a second control signal to enable or disable output of the second voltage to the second output node; and
a second limit switch coupled to the second input node and to a ground; and
a controller coupled to the first muscle wire controller and to the second muscle wire controller, the controller comprising:
a first pin configured to control and monitor an extend operation of the keyboard, wherein the controller is configured to control and monitor the extend operation through a single pin; and
a second pin configured to control and monitor a retract operation of the keyboard, wherein the controller is configured to control and monitor the retract operation through a single pin.
14. The apparatus of claim 13 , further comprising a lid coupled to the keyboard, wherein the controller is configured to:
control and monitor the retract operation of the keyboard when an angle between the retractable keyboard and the lid is within a predetermined range; and
control and monitor the extend operation of the keyboard when an angle between the retractable keyboard and the lid is out of the predetermined range.
15. The apparatus of claim 13 , wherein the first limit switch is configured to close only when the keyboard is extended to the first position and the second switch is configured to close only when the keyboard is retracted to the second position.
16. The apparatus of claim 13 , wherein the controller is configured to control and monitor through a single pin by determining whether the single pin floats high when not driven by the controller.
17. The apparatus of claim 13 , wherein the controller is configured to perform steps comprising:
driving the second pin to a floating high state to begin the retract operation; and
determining the retract operation is complete by monitoring the second pin.
18. The apparatus of claim 17 , wherein the controller is configured to perform steps further comprising driving the second pin to a low state after determining the retract operation is complete.
19. The apparatus of claim 13 , wherein the controller is configured to perform steps comprising:
driving the first pin to a floating high state to begin the extend operation;
determining the extend operation is complete by monitoring the first pin; and
driving the first pin to a low state after determining the extend operation is complete.
20. The apparatus of claim 19 , wherein the controller is configured with the first pin and the second pin in as an open drain connection.