Keypad Library

mikroPascal PRO for FT90x provides a library for working with 4x4 keypad. The library routines can also be used with 4x1, 4x2, or 4x3 keypad. For connections explanation see schematic at the bottom of this page.

External dependencies of Keypad Library

The following variable must be defined in all projects using Keypad Library:	Description :	Example :
`var keypadPort : byte; sfr; external;`	Keypad Port.	`var keypadPort : byte at GPIO_PORT_48_55;`

Keypad_Init

Prototype	procedure Keypad_Init();
Description	Initializes given port for working with keypad.
Parameters	None.
Returns	Nothing.
Requires	External dependencies of the library from the top of the page must be defined before using this function.
Example	GPIO_PORT_48_55// Keypad module connections var keypadPort : byte at GPIO_PORT_48_55; // End Keypad module connections ... Keypad_Init(); // Initialize Keypad
Notes	None.

Keypad_Key_Press

Prototype	function Keypad_Key_Press(): word;
Description	Reads the key from keypad when key gets pressed.
Parameters	None.
Returns	The code of a pressed key (1..16). If no key is pressed, returns 0.
Requires	Port needs to be initialized for working with the Keypad library, see Keypad_Init.
Example	var kp : word; ... kp := Keypad_Key_Press();
Notes	None.

Keypad_Key_Click

Prototype	function Keypad_Key_Click(): word;
Description	Call to `Keypad_Key_Click` is a blocking call: the function waits until some key is pressed and released. When released, the function returns 1 to 16, depending on the key. If more than one key is pressed simultaneously the function will wait until all pressed keys are released. After that the function will return the code of the first pressed key.
Parameters	None.
Returns	The code of a clicked key (1..16). If no key is clicked, returns 0.
Requires	Port needs to be initialized for working with the Keypad library, see Keypad_Init.
Example	kp := Keypad_Key_Click();
Notes	None.

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