237 lines
11 KiB
C
237 lines
11 KiB
C
#include "SIF.h"
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#include "common.h"
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#define DATA_REV_PIN gpio_get(SIF_REV_PIN)
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#ifdef _SIF_DEBUG_
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char log_str[128] = { 0 };
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#endif
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typedef enum {
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INITIAL_STATE = 0, // 初始状态,等待接收同步信号
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SYNC_L_STATE = 1, // 接收同步低电平信号状态
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SYNC_H_STATE = 2, // 接收同步高电平信号状态
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DATA_REV_STATE = 3, // 读取数据码电平状态
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END_SIGNAL_STATE = 4, // 接收结束电平信号状态
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RESTART_REV_STATE = 5 // 接收过程出错重新接收状态
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} REV_STATE_e; // 接收数据状态枚举
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unsigned char receive_state = 0; //接收数据状态
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unsigned char receive_bit_num = 0; //接收的bit位个数
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unsigned char receive_data_num = 0; //接收的数据个数
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unsigned char sif_receive_data_buf[REV_DATA_NUM] = { 0 }; //接收数据缓存数组如果一帧数据有多个数据打开注释
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unsigned char sif_receive_data[REV_DATA_NUM] = { 0 };
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unsigned int H_L_Level_time_cnt = 0; //高低电平时间计数
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unsigned int Tosc = TOSC; //波形时基单元，一般带波特率自适应的，不会说明高低电平的时间，会用一个Tosc时基描述
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//如上面的波形图，要求 32Tosc = 0.5ms = 500us
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//所以：一个Tosc = 500us/32 ≈ 15us，而定时器0单次定时时间为5us，所以实际一个Tosc = 15us/5us = 3 次
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//可以理解为 5us 是人为设置的一个定时器单次定时时间，再这个定时时间的基础上又产生了一个实际时基Tosc，用在波形上，波形基于这个Tosc时基单元
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//可以动态的调整高低电平的时间，只要Tosc改变，992Tosc和32Tosc以及64Tosc对应的时间也会随之改变；然后我们反过来思考，再不知道波特率的情况下，
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//去读取同步信号高电平的时间，将读到的时间计数H_L_Level_time_cnt * 15us是高电平的真实维持时间 = 32 * Tosc * 5us = SHORT_TIME_NUM * Tosc * 5us
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//Tosc = H_L_Level_time_cnt / SHORT_TIME_NUM
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//在本案例中，一帧数据 = 992Tosc+32Tosc+(64+32)*8*12Tosc = 10240*Tosc 次
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//1秒钟 = 1000000us，单次定时 5us，则1s / 5us = 200000 次
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//则1秒钟可以接收 200000 / (10240 * Tosc) = 200000/10240/Tosc = 19/Tosc 帧数据
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uint8_t start_H_L_Level_timming_flag = 0; //开始高低电平计时标记
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uint8_t has_read_bit = 0; //1-已经读取一个bit位
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uint8_t read_success = 0; //一帧数据是否读取成功，0-不成功，1-成功
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uint8_t is_end_bit = 0; // 结束帧判定 0-未结束,1-结束标志
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void GPIO_SIF_Init(void)
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{
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gpio_init(SIF_REV_PIN);
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gpio_set_dir(SIF_REV_PIN, GPIO_OUT);
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}
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void TIMER_SIF_IRQHandler(void)
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{
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if (start_H_L_Level_timming_flag == 1) {
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H_L_Level_time_cnt++; //高低电平维持时间计数变量
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}
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Receive_SIF_Data_Handle(); //接收数据处理，波特率自适应
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}
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void Receive_SIF_Data_Handle(void)
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{
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switch (receive_state) //检测当前接收数据状态
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{
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case INITIAL_STATE: //初始状态，未接收到同步信息，进行同步判断
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if (DATA_REV_PIN == LOW) //判断接收引脚的电平状态，当读到低电平时，开始计时
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{
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receive_bit_num = REV_BIT_NUM; //重置bit位计数器
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receive_data_num = 0; //重置接收数据个数
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H_L_Level_time_cnt = 0; //高低电平计时变量清0
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read_success = 0; //结束位置低电平判定清零
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start_H_L_Level_timming_flag = 1; //开始高低电平计时
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is_end_bit = 0;
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receive_state = SYNC_L_STATE; //进入读取同步低电平信号状态
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memset(sif_receive_data_buf, 0, 16);
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}
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break;
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case SYNC_L_STATE: //在读取同步低电平信号期间
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if (H_L_Level_time_cnt > SYNC_TIME_NUM * Tosc) //如果低电平时间 > SYNC_TIME_NUM*Tosc=992*3*5us
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{ //同步状态空闲时间大于15ms
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if (DATA_REV_PIN == HIGH) //判断接收引脚的电平状态，当读到高电平时
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{
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H_L_Level_time_cnt = 0; //高低电平计时变量清0
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receive_state = SYNC_H_STATE; //进入读取同步信号高电平状态
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}
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} else {
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if (DATA_REV_PIN == HIGH) //同步信号低电平检测期间读到高电平重新计时
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{
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receive_state = RESTART_REV_STATE; //进入重新接收状态
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}
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}
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break;
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case SYNC_H_STATE: //在读取同步高电平信号期间
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if (H_L_Level_time_cnt >= LOGIC_CYCLE_NUM * Tosc) //如果高电平时间超过了（32+64=96）个Tosc，则认为超时
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{
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receive_state = RESTART_REV_STATE; //进入重新接收状态
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} else {
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if (DATA_REV_PIN == LOW) //同步信号高电平检测期间读到低电平
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{
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//在同步信号高电平检测期间读到低电平可能有如下状态：
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//1、高电平时间短，不满32Tosc
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//2、高电平时间正好=32Tosc
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//3、高电平时间长，超过32Tosc
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//不管何种状态，都要 调整 Tosc 的值达到波特率自适应
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//H_L_Level_time_cnt * 5us 要求是 SHORT_TIME_NUM * Tosc * 5us，
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//即 H_L_Level_time_cnt = SHORT_TIME_NUM * Tosc
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Tosc = H_L_Level_time_cnt / SHORT_TIME_NUM; //调整 Tosc 的值
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H_L_Level_time_cnt = 0; //高低电平计时变量清0
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receive_state = DATA_REV_STATE; //进入读取数据码低电平状态
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}
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}
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break;
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case DATA_REV_STATE: //在读取数据码电平期间
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//逻辑"0"为 64Tosc低电平 + 32Tosc高电平
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//逻辑"1"为 32Tosc低电平 + 64Tosc高电平
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//不管是逻辑"0"还是逻辑"1"，周期一样，都是32Tosc + 64Tosc = 96Tosc
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//可以取中间时间点进行判断，96Tosc / 2 = 48Tosc，当计数>=48Tosc时读取引脚电平
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//如果还没有读取一个bit位，且时间计数已经>=48Tosc
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if ((has_read_bit == 0) && (H_L_Level_time_cnt >= (HALF_LOGIC_CYCLE * Tosc))) {
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sif_receive_data_buf[receive_data_num] |= DATA_REV_PIN;
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has_read_bit = 1;
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}
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//如果已经读取一个bit位，且时间计数已经>=96Tosc，说明一个逻辑周期过去了
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if ((has_read_bit == 1) && (H_L_Level_time_cnt >= (LOGIC_CYCLE_NUM * Tosc))) {
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H_L_Level_time_cnt = 0; //高低电平计时变量清0
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has_read_bit = 0; //清0，读取下一个bit位
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receive_bit_num--; //接收的bit数--
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if (receive_bit_num == 0) //如果一个字节8个bit位接收完成
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{
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receive_data_num++; //接收的数据个数++
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receive_bit_num = REV_BIT_NUM; //重置接收bit位个数
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if (receive_data_num >= REV_DATA_NUM) //如果数据采集完毕 超出了最大值
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{
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start_H_L_Level_timming_flag = 0; //停止高低电平计时
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H_L_Level_time_cnt = 0; //定时器计数值清0
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receive_state = INITIAL_STATE; //接收状态清0
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}
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} else //如果一个字节8个bit位还没有接收完成
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{
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//将接收数据缓存左移一位，数据从高bit位开始接收
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sif_receive_data_buf[receive_data_num] = sif_receive_data_buf[receive_data_num] << 1;
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}
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}
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// 记录 结束标志
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if (H_L_Level_time_cnt == (END_SIGNAL_FLAG_NUM * Tosc) && (DATA_REV_PIN == LOW)) {
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is_end_bit = 1;
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has_read_bit = 0;
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read_success = 1; //一帧数据读取成功
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#ifdef _SIF_DEBUG_
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sprintf(log_str, "rn:%d,%s.", receive_data_num, sif_receive_data_buf);
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#endif
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Check_Sum_Handle();
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start_H_L_Level_timming_flag = 0; //停止高低电平计时
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H_L_Level_time_cnt = 0; //定时器计数值清0
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receive_state = INITIAL_STATE; //接收状态清0
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}
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break;
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case END_SIGNAL_STATE: //在接收结束信号低电平期间
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if (DATA_REV_PIN == LOW) {
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if (H_L_Level_time_cnt >= END_SIGNAL_TIME_NUM * Tosc) //如果读到低电平时间>=5ms
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{
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read_success = 1; //一帧数据读取成功
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Check_Sum_Handle();
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start_H_L_Level_timming_flag = 0; //停止高低电平计时
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H_L_Level_time_cnt = 0; //定时器计数值清0
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receive_state = INITIAL_STATE; //接收状态清0
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}
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} else //结束信号低电平检测期间一直为低
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{
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//if (H_L_Level_time_cnt >= SYNC_L_TIME_NUM) //如果读到低电平时间>=10ms，认为超时
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{ //一帧数据发送完成后需要间隔50ms才发送第二帧数据，期间肯定会被拉高
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receive_state = RESTART_REV_STATE; //进入重新接收状态
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}
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}
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break;
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case RESTART_REV_STATE: //重新接收数据状态
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start_H_L_Level_timming_flag = 0; //停止高低电平计时
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H_L_Level_time_cnt = 0; //定时器计数值清0
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is_end_bit = 0;
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receive_state = INITIAL_STATE; //接收状态清0
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break;
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}
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}
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unsigned char *pGetSIFData(void) //获取SIF数据
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{
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return sif_receive_data;
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}
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#ifdef _SIF_DEBUG_
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char *pGetLogStr(void) //获取SIF数据
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{
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return log_str;
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}
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#endif
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void Check_Sum_Handle()
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{
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if (read_success == 1) //如果成功读取一帧数据
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{
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//一帧数据接收成功后先根据协议要求进行校验和，验证数据的正确性
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//如果数据正确，根据接收的数据进行分析获取需要的内容
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//if (check_OK)
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{
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memset(sif_receive_data, 0, REV_DATA_NUM);
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memcpy(sif_receive_data, sif_receive_data_buf, REV_DATA_NUM);
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memset(sif_receive_data_buf, 0, REV_DATA_NUM);
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}
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read_success = 0; //读取一帧数据清0
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}
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}
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void SIF(void *p)
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{
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(void)p;
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GPIO_SIF_Init();
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while (1)
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{
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char *SIF_DATA = (char *)pGetSIFData();
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printf("%s", SIF_DATA);
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vTaskDelay(pdMS_TO_TICKS(3000)); // 非阻塞延时
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}
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return ;
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}
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