Shai at 11:46, 15 March 2010

2010-03-15T11:46:28Z

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== GPIO Sample Application ==
=== Overview ===
This GPIOSample application demonstrates basic functionality of CM-X300 GPIOs under Windows CE:
* How to configure a GPIO pin as output and manipulate it.
* How to configure a GPIO pin as input and respond to changes in signal level.
* How to setup an edge triggered event.

=== Application Behavior ===
The GPIOSample manipulates the following GPIOs:
* GPIO 122 (pin 12 of connector P13 on the SB-X300) - Set as output
* GPIO 124 (pin 14 of connector P13 on the SB-X300) - Set as input
* GPIO 128 (Pin 24 of connector P11 on the SB-X300) - Set as input. (pin 0 on GPIO extender 0)

GPIO122 voltage level may be monitored with a DVM or an oscilloscope. GPIO124 and GPIO128 may be controlled by an external switch or button.

The GPIOSample performs the following actions:
* Edge detection on GPIO124 (cpu GPIO). Event handler is registered with [[#BOOL_GPIOUnRegisterInterrupt.28HANDLE_hDevice.2C_DWORD_num.29|GPIORegisterInterrupt]]. The handler calls [[#VOID_GPIOInterruptDone.28HANDLE_hDevice.2C_DWORD_num.29|GPIOInterruptDone]] to indicate interrupt completion.
* Edge detection on GPIO128 (GPIO extender). Event handler is registered with [[#BOOL_GPIOUnRegisterInterrupt.28HANDLE_hDevice.2C_DWORD_num.29|GPIORegisterInterrupt]]. The handler calls [[#VOID_GPIOInterruptDone.28HANDLE_hDevice.2C_DWORD_num.29|GPIOInterruptDone]] to indicate interrupt completion.
* Clock simulation on GPIO122 with a period of 3 seconds.
* Input voltage level monitoring on GPIO122.

== GPIO Driver API ==
=== Data Types ===
{{Enum| HeadLevel = ==== | Enumname = GPIO_VALUE |
Description = GPIO state enumeration|
Field1 = GPIO_LOW |
Field2 = GPIO_HIGH |
Field3 = |
Field4 = |
Remarks = |
}}

{{Enum| HeadLevel = ==== | Enumname = GPIO_EDGE_SETTINGS |
Description = |
Field1 = GPIO_REACT_ON_FALLING |
Field2 = GPIO_REACT_ON_RISING |
Field3 = GPIO_REACT_ON_BOTH |
Field4 = GPIO_DONT_REACT |
Remarks = |
}}

{{Struct| HeadLevel = ==== | Structname = GPIO_INTERRUPT |
Description = |
Field1 = DWORD dwGpioNum |
Fieldexp1 = |
Field2 = [[#GPIO_EDGE_SETTINGS|GPIO_EDGE_SETTINGS]] Edge|
Fieldexp2 = |
Field3 = HANDLE Event|
Fieldexp3 = |
Field4 = |
Field5 = |
Field6 = |
Field7 = |
Field8 = |
Remarks = |
}}

=== Functions ===
{{APIEx| HeadLevel = ==== | Signature = HANDLE GPIOOpen() |
Description = Opens an instance of the GPIO Driver. |
Return = Returns a handle that should be used to access the driver. Nonzero indicates success. |
Param1 = |
Param2 = |
Param3 = |
Param4 = |
Remarks = }}

{{APIEx| HeadLevel = ==== | Signature = void GPIOClose(HANDLE hDevice) |
Description = Closes the driver handle |
Return = |
Param1 = *hDevice - Handle to an open driver instance|
Param2 = |
Param3 = |
Param4 = |
Remarks = }}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIOSetValue(HANDLE hDevice,DWORD num, [[#GPIO_VALUE|GPIO_VALUE]] val) |
Description = Sets the state of a GPIO. |
Return = TRUE - indicates success
:FALSE - indicates failure|
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *num - GPIO number.|
Param3 = *val - The desired logical state. |
Param4 = |
Remarks = Make sure the GPIO direction is setup as output.}}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIOGetValue(HANDLE hDevice,DWORD num,[[#GPIO_VALUE|GPIO_VALUE]] *gpioVal) |
Description = Return the logical state of a GPIO.|
Return = TRUE - indicates success
:FALSE - indicates failure|
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *num - GPIO number.|
Param3 = *gpioVal - pointer to the GPIO state variable|
Param4 = |
Remarks = Make sure the GPIO direction is setup as input. Returned value for an output GPIO is undefined}}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIOSetAsInput(HANDLE hDevice, DWORD num) |
Description = Configures a GPIO as an input.|
Return = TRUE - indicates success
:FALSE - indicates failure|
Param1 = *hDevice - Handle to an open driver instance.|
Param2 = *num - GPIO number.|
Param3 = |
Param4 = |
Remarks = }}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIOSetAsOutput(HANDLE hDevice,DWORD num, [[#GPIO_VALUE|GPIO_VALUE]] val) |
Description = Configures a GPIO as an output and sets its logical state. |
Return = TRUE - indicates success
:FALSE - indicates failure|
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *num - GPIO number.|
Param3 = *val - The initial GPIO value|
Param4 = |
Remarks = }}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIORegisterInterrupt(HANDLE hDevice,[[#GPIO_INTERRUPT|GPIO_INTERRUPT]] interrupt) |
Description = Registers a GPIO as an interrupt source. The interrupt is triggered according to the configuration in [[#GPIO_INTERRUPT|GPIO_INTERRUPT]].Edge member settings. |
Return = TRUE - indicates success.
:FALSE - indicates failure|
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *interrupt- data structure that defines parameters for the interrupt registration |
Param3 = |
Param4 = |
Remarks = * The handle for the interrupt event is stored in [[#GPIO_INTERRUPT|GPIO_INTERRUPT]].Event|
:* This function must be called before using the [[#GPIO_INTERRUPT|GPIO_INTERRUPT]].Event parameter.
:* The [[#GPIO_INTERRUPT|GPIO_INTERRUPT]].Event parameter may only be used in a {{Cmd|WaitForSingleObject}} call. A {{Cmd|WaitForMultipleObjects}} call with [[#GPIO_INTERRUPT|GPIO_INTERRUPT]].Event will fail.
:* If you use GPIO_INTERRUPT.Event in a call to WaitForSingleObject before you call {{Cmd|GPIOInterruptInitialize}}, {{Cmd|GPIOInterruptInitialize}} will fail.
}}

{{APIEx| HeadLevel = ==== | Signature = VOID GPIOInterruptDone(HANDLE hDevice, DWORD num) |
Description = Signals to the kernel that GPIO interrupt processing is complete.|
Return = |
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *num - GPIO number.|
Param3 = |
Param4 = |
Remarks = A program calls {{Cmd|GPIOInterruptDone}} when it has completed the interrupt processing and is ready for another interrupt.}}

{{APIEx| HeadLevel = ==== | Signature = BOOL GPIOUnRegisterInterrupt(HANDLE hDevice, DWORD num) |
Description = Disables the GPIO hardware interrupt.|
Return = TRUE - indicates success.
:FALSE - indicates failure |
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *num - GPIO number.|
Param3 = |
Param4 = |
Remarks = A program calls {{Cmd|GPIOUnRegisterInterrupt}} to disable the hardware interrupt and to unregister the event that was registered by {{Cmd|GPIOInterruptInitialize}}.}}
[[Category:Windows CE|GPIOs Programming]]
[[Category:CM-X300|WinCE6.0: GPIOs Programming]]

CM-X300: WinCE: GPIOs Programming - Revision history

Shai at 11:46, 15 March 2010