MAX1233/MAX1234触摸屏控制器入门
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P R 6
T M2
0x0040 0x0b01
0x8000 0x0000
0x8001 0x0000
0x8002 0x0000
0x8003 0x0000
P R 6
P R 6
T M2
0x0040 0x0b01
0x8000 0x0000
0x8001 0x0000
0x8002 0x0000
0x8003 0x0000
P R 6
T M2
0x0040 0x0b01
0x8000 0x0000
0x8001 0x0000
0x8002 0x0000
0x8003 0x0000
P R 6
P R 6
T M2
0x0040 0x0b01
0x8000 0x0000
0x8001 0x0000
0x8002 0x0000
0x8003 0x0000
P R 6
3.5) 检测触摸屏操作：自动扫描
在检测触摸屏操作，配置MAX1234，自动数字化触摸屏的接触位置时，写入寄存器0x40 (ADC控制)，其PENSTS=1，ADSTS=0 (请参考MAX1233/MAX1234数据资料的表6)。第一次接触屏幕时，/PENIRQ信号暂时变为低电平，并在读取X寄存器之前不会变化。表13. 触摸屏检测命令序列：自动扫描
DEMO1234 Command | Action | SPI data in | Verification |
| Optional: connect oscilloscope to PENIRQ-bar | |||
I C 1 3 | Configure PENIRQ-bar pulse accumulator: falling-edge trigger | ||
I 0 1 | Reset the pulse accumulator | ||
I R 1 | Read the number of times PENIRQ-bar has pulsed low | count = 0 | |
T W AC 8bff | Wait for touch, then scan X,Y,Z1,Z2 | 0x0040 0x8bff | |
| Touch the touch screen | PENIRQ pulse | ||
I R 1 | Read the number of times PENIRQ-bar has pulsed low | count has increased | |
T R P | Read X,Y,Z1,Z2 conversion results | 0x8000 0x0000 0x8001 0x0000 0x8002 0x0000 0x8003 0x0000 | |
| Touch the touch screen | PENIRQ pulse | ||
I R 1 | Read the number of times PENIRQ-bar has pulsed low | count has increased | |
T R P | Read X,Y,Z1,Z2 conversion results | 0x8000 0x0000 0x8001 0x0000 0x8002 0x0000 0x8003 0x0000 | |
| Touch the touch screen | PENIRQ pulse | ||
I R 1 | Read the number of times PENIRQ-bar has pulsed low | count has increased | |
T R P | Read X,Y,Z1,Z2 conversion results | 0x8000 0x0000 0x8001 0x0000 0x8002 0x0000 0x8003 0x0000 |
4) 键盘和通用输入/输出引脚
下面的例子介绍了怎样使用DEMO1234.EXE程序来扫描键盘，怎样使用GPIO键盘扫描引脚。4.1) 配置键盘和GPIO引脚
GPIO控制寄存器将每个C1–C4和R1–R4引脚分别配置为输入、输出或者是键盘的一部分(请参考MAX1233/MAX1234数据资料的表26和表27)。此外，写入GPIO上拉禁止寄存器，将输出引脚配置为开漏输出。表14. 键盘和GPIO配置实例
DEMO1234 Command | Action | SPI data in |
T W GC FFFF | Keypad: none; GPIO outputs: C4,C3,C2,C1,R4,R3,R2,R1; GPIO inputs: none | 0x004f 0xffff |
T W GC FF00 | Keypad: none; GPIO outputs: none; GPIO inputs: C4,C3,C2,C1,R4,R3,R2,R1 | 0x004f 0xff00 |
T W GC 0000 | Keypad: (C4,C3,C2,C1) x (R4,R3,R2,R1); GPIO outputs: none; GPIO inputs: none | 0x004f 0x0000 |
T W GC C8C0 | Keypad: (C2,C1) x (R3,R2,R1); GPIO outputs: C4,C3; GPIO input: R4 | 0x004f 0xc8c0 |
T W GP 4000 | GPIO pullup disable: C3 | 0x004e 0x4000 |
4.2) 读写GPIO引脚
GPIO数据寄存器读取GPIO输入引脚，写入GPIO输出引脚。注意：在这些例子中，C3、C4和R4是引脚名称，而不是元件名称。表15. GPIO实例
DEMO1234 Command | Action | SPI data in | Verification |
T W GC C8C0 | Keypad: (C2,C1) x (R3,R2,R1); GPIO outputs: C4,C3; GPIO input: R4 | 0x004f 0xc8c0 | |
T W GP 4000 | GPIO pullup disable: C3 | 0x004e 0x4000 | |
| Connect external resistor between C3 pin and DVDD | |||
| Connect DVM to C4 pin | |||
T W GD 8000 | GPIO write C4 = 1 | 0x000f 0x8000 | C4 pin = high |
T W GD 0000 | GPIO write C4 = 0 | 0x000f 0x0000 | C4 pin = low |
T W GD 8000 | GPIO write C4 = 1 | 0x000f 0x8000 | C4 pin = high |
T W GD 0000 | GPIO write C4 = 0 | 0x000f 0x0000 | C4 pin = low |
| Connect DVM to C3 pin | |||
T W GD 4000 | GPIO write C3 = 1 | 0x000f 0x4000 | C3 pin = high |
T W GD 0000 | GPIO write C3 = 0 | 0x000f 0x0000 | C3 pin = low |
T W GD 4000 | GPIO write C3 = 1 | 0x000f 0x4000 | C3 pin = high |
T W GD 0000 | GPIO write C3 = 0 | 0x000f 0x0000 | C3 pin = low |
| Connect R4 pin to DVDD | |||
T R GD | GPIO read | 0x800f 0x0000 | Buffer = 0x0800 |
| Connect R4 pin to GND | |||
T R GD | GPIO read | 0x800f 0x0000 | Buffer = 0x0000 |
4.3) 检测按键：自动扫描
可以配置键盘控制寄存器在探测到有按键按下时，自动扫描键盘。表16. 按键命令序列：自动扫描
DEMO1234 Command | Action | SPI data in | Verification |
| Optional: connect oscilloscope to KEYIRQ-bar |
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