MAX1233/MAX1234触摸屏控制器入门

文章摘要：4.4) 从键盘中屏蔽单个按键使用键盘屏蔽寄存器和键盘2结果寄存器来屏蔽每个按键。屏蔽掉的按键被扫描至KPD寄存器，但是不在键盘2结果寄存器中报告。表17. 按键命令序列：屏蔽单个按键 DEMO1234 CommandActionSPI data inVerificationT W GC 0000Keypad:(C4,C3,C2,C1) x (R4,R3,R2,R1);GPIO outputs: none;GPIO inputs: none0x004f 0x0000T W KC bf00Wait for keypress;maximum debounce and hold times0x004

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4.4) 从键盘中屏蔽单个按键

使用键盘屏蔽寄存器和键盘2结果寄存器来屏蔽每个按键。屏蔽掉的按键被扫描至KPD寄存器，但是不在键盘2结果寄存器中报告。

表17. 按键命令序列：屏蔽单个按键

DEMO1234 Command	Action	SPI data in	Verification
T W GC 0000	Keypad: (C4,C3,C2,C1) x (R4,R3,R2,R1); GPIO outputs: none; GPIO inputs: none	0x004f 0x0000
T W KC bf00	Wait for keypress; maximum debounce and hold times	0x0041 0xbf00
T W KM 0020	Mask only R2C2 key	0x0050 0x0020
	Press and release R1C1 (key "1")
T R KB	Read raw keypad result	0x8004 0x0000	0x0001 = R1C1 key
T R K2	Read masked keypad result	0x8011 0x0000	0x0001 = R1C1 key
	Press and release R2C2 (key "5")
T R KB	Read raw keypad result	0x8004 0x0000	0x0020 = R2C2 key
T R K2	Read masked keypad result	0x8011 0x0000	0x0000 = no key
	Press and release R3C2 (key "8")
T R KB	Read raw keypad result	0x8004 0x0000	0x0040 = R3C2 key
T R K2	Read masked keypad result	0x8011 0x0000	0x0040 = R3C2 key

4.5) 从键盘中屏蔽一列

使用键盘列寄存器来屏蔽所有列。不扫描屏蔽列，因此，KPD寄存器不会探测这些列中的按键。

表18. 按键命令序列：屏蔽键盘的一列

DEMO1234 Command	Action	SPI data in	Verification
T W GC 0000	Keypad: (C4,C3,C2,C1) x (R4,R3,R2,R1); GPIO outputs: none; GPIO inputs: none	0x004f 0x0000
T W KC bf00	Wait for keypress; maximum debounce and hold times	0x0041 0xbf00
T W KK 2000	Mask entire C2 column	0x0051 0x2000
	Press and release R1C1 (key "1")
T R KB	Read raw keypad result	0x8004 0x0000	0x0001 = R1C1 key
	Press and release R2C2 (key "5")
T R KB	Read raw keypad result	0x8004 0x0000	(previous value)
	Press and release R3C2 (key "8")
T R KB	Read raw keypad result	0x8004 0x0000	(previous value)
	Press and release R2C3 (key "6")
T R KB	Read raw keypad result	0x8004 0x0000	0x0200 = R2C3 key

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