| I2C讀寫巨慢, 即使在400kbit/s下, 讀寫一個字節數據也要花費20多us, 這太慢了, 每讀寫一次設備的寄存器數據, 還要設備地址和寄存器地址, 又加了兩個字節數據, 我就讀了個傳感器的兩個字節數據而已, 動輒還要花費100us的阻塞時間, 這太浪費資源了 針對這個問題, 我利用硬件I2C及中斷配合, 實現了這個全程沒有任何阻塞MCU來讀寫I2C設備的方法, 效率大大提升 單片機采用stc32g8k64, 主頻為40Mhz, 讀寫LDC1612電感渦流傳感器為例來測試異步讀寫I2C數據 |
/*** stc32g8k64 硬件i2c 實現 無阻塞異步執行* ldc1612 i2c異步讀寫測試*/
#include <STC32G.h>
#include <stdio.h>
#define FOSC 40000000UL // 主頻40Mvoid Delay1ms(void) //@40.000MHz
{unsigned char data i, j;i = 39;j = 230;do{while (--j);} while (--i);
}
void delay(uint16 ms)
{while (ms--){Delay1ms();}
}// ---------------------- uart1打印測試用 開始----------------------------
bit busy;
char wptr;
char rptr;
char buffer[16];void Uart1_Isr(void) interrupt 4
{if (TI){TI = 0;busy = 0;}if (RI){RI = 0;buffer[wptr++] = SBUF;wptr &= 0x0f;}
}
void Uart1_Init(void) // 1000000bps@40.000MHz
{SCON = 0x50; // 8位數據,可變波特率AUXR |= 0x40; // 定時器時鐘1T模式AUXR &= 0xFE; // 串口1選擇定時器1為波特率發生器TMOD &= 0x0F; // 設置定時器模式TL1 = 0xF6; // 設置定時初始值TH1 = 0xFF; // 設置定時初始值ET1 = 0; // 禁止定時器中斷TR1 = 1; // 定時器1開始計時ES = 1; // 使能串口1中斷
}
void UartSend(char dat)
{while (busy);busy = 1;SBUF = dat;
}
void UartSendStr(char *p)
{while (*p){UartSend(*p++);}
}char sendNumberCharArr[20];
// 實現一個uint32轉char的方法
void numberToChar(uint32 number, char *buffer)
{char temp[12]; // Maximum digits for uint32 + null terminatorint i = 0;int j = 0;// Handle zero caseif (number == 0){buffer[0] = '0';buffer[1] = '\0';return;}// Extract digits in reverse orderwhile (number > 0){temp[i++] = (number % 10) + '0';number /= 10;}// Reverse the string to correct orderwhile (i > 0){buffer[j++] = temp[--i];}buffer[j] = '\0'; // Null terminate
}
// ---------------------- uart1打印測試用 結束----------------------------//------------------------------- I2C異步執行棧 開始 -----------------------------
sbit ET4 = IE2 ^ 6;
typedef void (*AsyncFunc)(void);
AsyncFunc AsyncFuncNext_callback = NULL;
// 延時執行下一個任務
void AsyncFuncNext(AsyncFunc callback, uint16 usDelay)
{uint16 totalTime = 0xffff - usDelay;T4T3M &= ~0x80;ET4 = 0;T4L = totalTime & 0xff; // 設置定時初始值T4H = totalTime >> 8; // 設置定時初始值AsyncFuncNext_callback = callback;T4T3M |= 0x80; // 定時器4開始計時ET4 = 1; // 使能中斷
}
// 定時器用于異步執行
void Timer4_Init(void) //@40.000MHz
{// 1us計時一個數字TM4PS = 0x27; // 設置定時器時鐘預分頻T4T3M |= 0x20; // 定時器時鐘1T模式T4L = 0x00; // 設置定時初始值T4H = 0x00; // 設置定時初始值T4T3M &= ~0x80; // 定時器4停止計時ET4 = 0;
}
// 定時器4用作異步執行定時器, 延時觸發下一步的執行函數
void Timer4_async_next_isr() interrupt 20
{T4T3M &= ~0x80;ET4 = 0;if (AsyncFuncNext_callback != NULL){AsyncFuncNext_callback();}
}
AsyncFunc I2C_Isr_callback = NULL; // I2C中斷回調函數
void I2C_Isr() interrupt 24 // I2C中斷
{if (I2CMSST & 0x40){I2CMSST &= ~0x40; // 清中斷標志if (I2C_Isr_callback != NULL){I2C_Isr_callback();}}
}
//------------------------------- 異步執行棧 結束 -----------------------------//------------------------------- I2C寄存器操作 開始 --------------------------
void Wait_I2C()
{while (!(I2CMSST & 0x40));I2CMSST &= ~0x40;
}uint8 i2c_readRegister16Async_addr = 0; // readRegister16Async 地址參數
uint8 i2c_readRegister16Async_reg = 0; // readRegister16Async 寄存器參數
uint8 i2c_readRegister16Async_step = 0; // readRegister16Async 異步執行步驟
uint16 i2c_readRegister16Async_value = 0; // readRegister16Async 讀取數據返回值
AsyncFunc i2c_readRegister16Async_endCallback = NULL; // readRegister16Async 讀取數據完成回調
void i2c_readRegister16Async_timeout()
{i2c_readRegister16Async_value = 0;i2c_readRegister16Async_step = 0;I2C_Isr_callback = NULL;I2CMSST = 0x00;if (i2c_readRegister16Async_endCallback != NULL){i2c_readRegister16Async_endCallback();}
}
// I2C異步讀取, 16位寄存器
void i2c_readRegister16Async()
{if (i2c_readRegister16Async_step == 1){I2CTXD = i2c_readRegister16Async_addr << 1; // 發送i2c地址I2CMSCR = 0x89; // 中斷使能, 發送起始信號+設備地址+寫信號i2c_readRegister16Async_step++;AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 2){I2CTXD = i2c_readRegister16Async_reg; // 發送讀取寄存器地址I2CMSCR = 0x8A; // 中斷使能, 發送數據命令+接收ACK命令i2c_readRegister16Async_step++;AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 3){I2CTXD = i2c_readRegister16Async_addr << 1 | 0x01; // 發送i2c地址+讀取數據I2CMSCR = 0x89; // 中斷使能, 發送起始信號+設備地址+寫信號i2c_readRegister16Async_step++;AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 4){I2CMSST = 0x00; // 設置 ACK 信號I2CMSCR = 0x8B; // 中斷使能, 接收數據命令+發送ACK(0)命令i2c_readRegister16Async_step++;AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 5){i2c_readRegister16Async_value = I2CRXD;i2c_readRegister16Async_value <<= 8;I2CMSST = 0x01; // 設置 NAK 信號I2CMSCR = 0x8C; // 中斷使能, 接收數據命令+發送NAK(1)命令i2c_readRegister16Async_step++;AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 6){i2c_readRegister16Async_value |= I2CRXD;i2c_readRegister16Async_step++;I2CMSCR = 0x86; // 中斷使能, 發送 STOP 命令AsyncFuncNext(i2c_readRegister16Async_timeout, 200);return;}if (i2c_readRegister16Async_step == 7){I2C_Isr_callback = NULL;i2c_readRegister16Async_step = 0;AsyncFuncNext(i2c_readRegister16Async_endCallback, 20);return;}
}
// 使用異步來讀取i2c數據
void i2c_readRegister16Async_start(uint8 addr, uint8 reg, AsyncFunc readEndCallback)
{i2c_readRegister16Async_addr = addr;i2c_readRegister16Async_reg = reg;i2c_readRegister16Async_value = 0;i2c_readRegister16Async_step = 1;I2C_Isr_callback = i2c_readRegister16Async;i2c_readRegister16Async_endCallback = readEndCallback;i2c_readRegister16Async();
}
// I2C同步讀取, 16位寄存器
uint16 i2c_readRegister16(uint8 addr, uint8 reg)
{uint16 readDataValue = 0;I2CTXD = addr << 1; // 寫數據到數據緩沖區I2CMSCR = 0x09; // 發送起始信號+設備地址+寫信號Wait_I2C();I2CTXD = reg; // 寫數據到數據緩沖區I2CMSCR = 0x0A; // 發送數據命令+接收ACK命令Wait_I2C();I2CTXD = addr << 1 | 0x01; // 發送i2c地址+讀取數據I2CMSCR = 0x09; // 發送起始信號+設備地址+寫信號Wait_I2C();I2CMSST = 0x00; // 設置 ACK 信號I2CMSCR = 0x0B; // 接收數據命令+發送ACK(0)命令Wait_I2C();readDataValue = I2CRXD;readDataValue <<= 8;I2CMSST = 0x01; // 設置 NAK 信號I2CMSCR = 0x0C; // 接收數據命令+發送NAK(1)命令Wait_I2C();readDataValue |= I2CRXD;I2CMSCR = 0x06; // 發送 STOP 命令Wait_I2C();return readDataValue;
}uint8 i2c_writeRegister16Async_addr = 0; // writeRegister16Async 地址參數
uint8 i2c_writeRegister16Async_reg = 0; // writeRegister16Async 寄存器參數
uint8 i2c_writeRegister16Async_step = 0; // writeRegister16Async 異步執行步驟
uint16 i2c_writeRegister16Async_value = 0; // writeRegister16Async 寫入數據
AsyncFunc i2c_writeRegister16Async_endCallback = NULL; // writeRegister16Async 讀取數據完成回調
// 異步寫16位寄存器超時
void i2c_writeRegister16Async_timeout()
{i2c_writeRegister16Async_value = 0;i2c_writeRegister16Async_step = 0;I2C_Isr_callback = NULL;I2CMSST = 0x00;if (i2c_writeRegister16Async_endCallback != NULL){i2c_writeRegister16Async_endCallback();}
}
// 異步寫16位寄存器
void i2c_writeRegister16Async()
{if (i2c_writeRegister16Async_step == 1){I2CTXD = i2c_writeRegister16Async_addr << 1; // 寫數據到數據緩沖區I2CMSCR = 0x89; // 發送起始信號+設備地址+寫信號i2c_writeRegister16Async_step++;AsyncFuncNext(i2c_writeRegister16Async_timeout, 200);return;}if (i2c_writeRegister16Async_step == 2){I2CTXD = i2c_writeRegister16Async_reg; // 寫數據到數據緩沖區I2CMSCR = 0x8A; // 發送數據命令+接收ACK命令i2c_writeRegister16Async_step++;AsyncFuncNext(i2c_writeRegister16Async_timeout, 200);return;}if (i2c_writeRegister16Async_step == 3){I2CTXD = (i2c_writeRegister16Async_value >> 8) & 0xFF; // 寫數據到數據緩沖區I2CMSCR = 0x8A; // 發送數據命令+接收ACK命令i2c_writeRegister16Async_step++;AsyncFuncNext(i2c_writeRegister16Async_timeout, 200);return;}if (i2c_writeRegister16Async_step == 4){I2CTXD = i2c_writeRegister16Async_value & 0xFF; // 寫數據到數據緩沖區I2CMSCR = 0x8A; // 發送數據命令+接收ACK命令i2c_writeRegister16Async_step++;AsyncFuncNext(i2c_writeRegister16Async_timeout, 200);return;}if (i2c_writeRegister16Async_step == 5){I2CMSCR = 0x86; // 發送 STOP 命令i2c_writeRegister16Async_step++;AsyncFuncNext(i2c_writeRegister16Async_timeout, 200);return;}if (i2c_writeRegister16Async_step == 6){I2C_Isr_callback = NULL;i2c_writeRegister16Async_step = 0;AsyncFuncNext(i2c_writeRegister16Async_endCallback, 20);return;}
}
// 使用異步來寫入i2c數據
void i2c_writeRegister16Async_start(uint8 addr, uint8 reg, uint16 value, AsyncFunc writeEndCallback)
{i2c_writeRegister16Async_addr = addr;i2c_writeRegister16Async_reg = reg;i2c_writeRegister16Async_value = value;I2C_Isr_callback = i2c_writeRegister16Async;i2c_writeRegister16Async_endCallback = writeEndCallback;i2c_writeRegister16Async_step = 1;i2c_writeRegister16Async();
}
// 同步寫16位寄存器
void i2c_writeRegister16(uint8 addr, uint8 reg, uint16 value)
{I2CTXD = addr << 1; // 寫數據到數據緩沖區I2CMSCR = 0x09; // 發送起始信號+設備地址+寫信號Wait_I2C();I2CTXD = reg; // 寫數據到數據緩沖區I2CMSCR = 0x0A; // 發送數據命令+接收ACK命令Wait_I2C();I2CTXD = (value >> 8) & 0xFF; // 寫數據到數據緩沖區I2CMSCR = 0x0A; // 發送數據命令+接收ACK命令Wait_I2C();I2CTXD = value & 0xFF; // 寫數據到數據緩沖區I2CMSCR = 0x0A; // 發送數據命令+接收ACK命令Wait_I2C();I2CMSCR = 0x06; // 發送 STOP 命令Wait_I2C();
}
//------------------------------- I2C寄存器操作 結束 --------------------------//------------------------------- LDC1612操作 開始 ----------------------------
#define SD_PIN P1_6 // SD引腳
#define INTB_PIN P1_7 // 數據就緒中斷
#define CLKIN_PIN P1_3 // 外部時鐘引腳// LDC1612 寄存器地址
#define LDC1612_ADDR 0x2A // I2C地址 (ADDR接地時)
#define REG_DATA_MSB_CH0 0x00 // 通道0數據高16位
#define REG_DATA_LSB_CH0 0x01 // 通道0數據低16位
#define REG_DATA_MSB_CH1 0x02 // 通道1數據高16位
#define REG_DATA_LSB_CH1 0x03 // 通道1數據低16位
#define REG_RCOUNT_CH0 0x08 // 通道0轉換計數
#define REG_RCOUNT_CH1 0x09 // 通道1轉換計數
#define REG_SETTLE_CNT_CH0 0x10 // 通道0穩定計數
#define REG_SETTLE_CNT_CH1 0x11 // 通道1穩定計數
#define REG_CLOCK_DIVIDERS_CH0 0x14 // 通道0時鐘分頻
#define REG_CLOCK_DIVIDERS_CH1 0x15 // 通道1時鐘分頻
#define REG_STATUS 0x18 // 狀態寄存器
#define REG_ERROR_CONFIG 0x19 // 錯誤配置
#define REG_CONFIG 0x1A // 配置寄存器
#define REG_MUX_CONFIG 0x1B // 多路復用配置
#define REG_RESET_DEV 0x1C // 設備復位
#define REG_DRIVE_CURRENT_CH0 0x1E // 通道0驅動電流
#define REG_DRIVE_CURRENT_CH1 0x1F // 通道1驅動電流// 配置常量
#define CONVERSION_TIME 0x0850 // 轉換時間設置
#define SETTLE_TIME 0x0400 // 穩定時間設置
#define CLOCK_DIVIDER 0x1001 // 時鐘分頻設置
#define DRIVE_CURRENT 0x1C00 // 驅動電流設置 (最大電流)
// 全局變量
uint32 ch0_value = 0;
uint32 ch1_value = 0;
uint8 LDC1612_read_ready = 0;
uint8 LDC1612_data_ready = 0;uint16 LDC1612_readDataAsync_msb = 0;
uint16 LDC1612_readDataAsync_lsb = 0;
uint16 LDC1612_readDataAsync_step = 0;
uint8 LDC1612_readDataAsync_isStart = 0;
// 異步讀取傳感器數據
void LDC1612_readDataAsync()
{if (LDC1612_readDataAsync_step == 1){LDC1612_readDataAsync_step++;AsyncFuncNext(LDC1612_readDataAsync, 100);i2c_readRegister16Async_start(LDC1612_ADDR, REG_STATUS, LDC1612_readDataAsync);return;}if (LDC1612_readDataAsync_step == 2){LDC1612_readDataAsync_step++;i2c_readRegister16Async_start(LDC1612_ADDR, REG_DATA_MSB_CH0, LDC1612_readDataAsync);return;}if (LDC1612_readDataAsync_step == 3){LDC1612_readDataAsync_step++;LDC1612_readDataAsync_msb = i2c_readRegister16Async_value;i2c_readRegister16Async_start(LDC1612_ADDR, REG_DATA_LSB_CH0, LDC1612_readDataAsync);return;}if (LDC1612_readDataAsync_step == 4){LDC1612_readDataAsync_step = 0;LDC1612_readDataAsync_lsb = i2c_readRegister16Async_value;ch0_value = ((uint32)LDC1612_readDataAsync_msb << 16) | LDC1612_readDataAsync_lsb;ch0_value &= 0x0FFFFFFF; // 保留28位有效數據ch0_value >>= 12; // 轉為16位數據LDC1612_data_ready = 1; // 讀取數據完成return;}
}
// 同步讀取傳感器數據
void LDC1612_readData()
{uint16 msb = 0;uint16 lsb = 0;// 讀取狀態寄存器uint16 status = i2c_readRegister16(LDC1612_ADDR, REG_STATUS);// 檢查錯誤標志if (status & 0x0008){// Serial.println("Error: Amplitude too low!");}if (status & 0x0010){// Serial.println("Error: Timeout occurred!");}// 讀取通道0數據msb = i2c_readRegister16(LDC1612_ADDR, REG_DATA_MSB_CH0);lsb = i2c_readRegister16(LDC1612_ADDR, REG_DATA_LSB_CH0);ch0_value = ((uint32)msb << 16) | lsb;ch0_value &= 0x0FFFFFFF; // 保留28位有效數據ch0_value >>= 12;LDC1612_data_ready = 1; // 讀取數據完成
}uint8 LDC1612_writeInitReg_step = 0;
// 異步方法寫入寄存器值
void LDC1612_writeInitRegAsync()
{// 配置通道0if (LDC1612_writeInitReg_step == 1){LDC1612_writeInitReg_step++;i2c_writeRegister16Async_start(LDC1612_ADDR, REG_RCOUNT_CH0, CONVERSION_TIME, LDC1612_writeInitRegAsync);return;}if (LDC1612_writeInitReg_step == 2){LDC1612_writeInitReg_step++;i2c_writeRegister16Async_start(LDC1612_ADDR, REG_SETTLE_CNT_CH0, SETTLE_TIME, LDC1612_writeInitRegAsync);return;}if (LDC1612_writeInitReg_step == 3){LDC1612_writeInitReg_step++;i2c_writeRegister16Async_start(LDC1612_ADDR, REG_CLOCK_DIVIDERS_CH0, CLOCK_DIVIDER, LDC1612_writeInitRegAsync);return;}if (LDC1612_writeInitReg_step == 4){LDC1612_writeInitReg_step++;i2c_writeRegister16Async_start(LDC1612_ADDR, REG_DRIVE_CURRENT_CH0, DRIVE_CURRENT, LDC1612_writeInitRegAsync);return;}// 配置錯誤檢測if (LDC1612_writeInitReg_step == 5){LDC1612_writeInitReg_step++;// 啟用數據輸出錯誤檢測i2c_writeRegister16Async_start(LDC1612_ADDR, REG_ERROR_CONFIG, 0x0001, LDC1612_writeInitRegAsync);return;}// 配置多路復用器 - 只啟用通道0if (LDC1612_writeInitReg_step == 6){LDC1612_writeInitReg_step++;// 只掃描通道0，去抖動計數=1i2c_writeRegister16Async_start(LDC1612_ADDR, REG_MUX_CONFIG, 0x0208, LDC1612_writeInitRegAsync);return;}// 配置主配置寄存器if (LDC1612_writeInitReg_step == 7){LDC1612_writeInitReg_step++;// 啟用傳感器，單通道模式i2c_writeRegister16Async_start(LDC1612_ADDR, REG_CONFIG, 0x1401, LDC1612_writeInitRegAsync);return;}// 初始化完成if (LDC1612_writeInitReg_step == 8){LDC1612_writeInitReg_step = 0;return;}
}
// 同步方法寫入寄存器值
void LDC1612_writeInitReg()
{// 配置通道0i2c_writeRegister16(LDC1612_ADDR, REG_RCOUNT_CH0, CONVERSION_TIME);i2c_writeRegister16(LDC1612_ADDR, REG_SETTLE_CNT_CH0, SETTLE_TIME);i2c_writeRegister16(LDC1612_ADDR, REG_CLOCK_DIVIDERS_CH0, CLOCK_DIVIDER);i2c_writeRegister16(LDC1612_ADDR, REG_DRIVE_CURRENT_CH0, DRIVE_CURRENT);// 配置錯誤檢測i2c_writeRegister16(LDC1612_ADDR, REG_ERROR_CONFIG, 0x0001); // 啟用數據輸出錯誤檢測// 配置多路復用器 - 只啟用通道0i2c_writeRegister16(LDC1612_ADDR, REG_MUX_CONFIG, 0x0208); // 只掃描通道0，去抖動計數=1// 配置主配置寄存器i2c_writeRegister16(LDC1612_ADDR, REG_CONFIG, 0x1401); // 啟用傳感器，單通道模式
}// LDC1612 中斷服務程序 (數據就緒)
void LDC1612_ready_isr() interrupt 38
{unsigned char intf;intf = P1INTF;if (intf){P1INTF = 0x00;// P1.7 口中斷if (intf & 0x80){LDC1612_read_ready = 1;}}
}void initI2C()
{P_SW2 = 0x80; // 使能訪問XFRP1PU |= 0x30; // P1.4和P1.5使能4K上拉電阻P1M1 |= 0x10;P1M0 |= 0x10; // P1.4(SDA)開漏輸出P1M1 |= 0x20;P1M0 |= 0x20; // P1.5(SCL)開漏輸出// I2C總線速度計算: SYSCLK / 2 / (MSSPEED * 2 + 4)// 對于400KHz: MSSPEED = (40M / 400K / 2 - 4) / 2 = 23 (0x17)I2CCFG = 0x80 | 0x40 | 0x17; // 使能I2C + 主機模式 + 400KHz速度I2CMSST = 0x00; // 清除狀態寄存器IP2H |= 0x40; // 設置I2c中斷的優先級為高IP2 |= 0x40; // 設置I2c中斷的優先級為高
}// LDC1612初始化
void initLDC1612()
{// p1.6 SDP1M1 &= ~0x40;P1M0 |= 0x40; // 推挽輸出// p1.3 CLKIN_PINP1M1 &= ~0x08;P1M0 |= 0x08; // 推挽輸出// p1.7 INTB 數據準備好中斷P1M1 |= 0x80;P1M0 &= ~0x80; // 高阻輸入SD_PIN = 0; // 低電平使能ldc1612CLKIN_PIN = 0; // 禁用外部時鐘引腳P1IM0 = 0x00; // 下降沿中斷P1IM1 = 0x00;P1INTE = 0x80; // 使能 p1.7 口中斷Timer4_Init();initI2C();delay(50);// 同步方法寫入寄存器// LDC1612_writeInitReg();// 異步方式寫入寄存器LDC1612_writeInitReg_step = 1;LDC1612_writeInitRegAsync();
}
//------------------------------- LDC1612操作 結束 ----------------------------void main(void)
{P_SW2 = 0x80; // 使能訪問XFRWTST = 0; // 設置程序指令延時參數，賦值為0可將CPU執行指令的速度設置為最快CKCON = 0; // 提高訪問XRAM速度Uart1_Init(); // 初始化串口 1M波特率EA = 1; // 允許總中斷initLDC1612();UartSendStr("setup\n");while (1){if (LDC1612_read_ready == 1){LDC1612_read_ready = 0;// 同步讀取傳感器數據// LDC1612_readData();// i2c無阻塞異步讀取傳感器數據LDC1612_readDataAsync_step = 1;LDC1612_readDataAsync();}if (LDC1612_data_ready == 1){LDC1612_data_ready = 0;UartSendStr("LDC1612 data:");numberToChar(ch0_value, sendNumberCharArr);UartSendStr(sendNumberCharArr);UartSendStr("\n");}}
}
