2025-03-20 16:36:10 +08:00
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/* KeyScan.c - 按键扫描模块 */
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2025-03-19 18:22:32 +08:00
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#include "KeyScan.h"
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2025-03-20 16:36:10 +08:00
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// 按键状态机结构体
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typedef struct
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{
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uint8_t prev_state; // 前次状态
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uint8_t edge_trigger; // 边沿触发标志
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uint8_t scan_counter; // 扫描计数器
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} KeyStateMachine;
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static KeyStateMachine key_state = { 0xFF, 0x00, 0 };
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/*******************************************
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* 初始化函数
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*******************************************/
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void
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Key_Init (void)
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{
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// 配置P2.4-P2.1为准双向口
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P2M0 &= 0xE1;
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P2M1 &= 0xE1;
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// 初始化按键状态
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key_state.prev_state = (KEY1 * 0x08) | (KEY2 * 0x04) | (KEY3 * 0x02) | KEY4;
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}
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/*******************************************
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* 按键扫描函数
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* 需在主循环中周期性调用
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*******************************************/
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void
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Key_Scan (void)
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{
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const uint8_t current = (KEY1 * 0x08) | (KEY2 * 0x04) | (KEY3 * 0x02) | KEY4;
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// 边沿检测
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const uint8_t falling_edge
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= (key_state.prev_state ^ current) & key_state.prev_state;
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key_state.edge_trigger |= falling_edge; // 累积触发事件
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key_state.prev_state = current; // 更新历史状态
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2025-03-19 18:22:32 +08:00
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}
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2025-03-20 16:36:10 +08:00
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/*******************************************
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* 按键事件获取接口（供外部模块调用）
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* 返回：4位掩码，对应KEY4-KEY1的触发状态
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*******************************************/
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uint8_t
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Get_KeyEvents (void)
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{
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const uint8_t events = key_state.edge_trigger;
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key_state.edge_trigger = 0; // 读取后清除标志
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return events;
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}
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