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QEI

QEI. QUADRATURE ENCODER INTERFACE (QEI) Ken Wang ~. CNTERR: QESIDL: 0: 繼續動作 1: 閒置模式 UPDN : 0: timer 向下計數 1: timer 向上計數 QEIM<2:0> : QEI Mode Select bit 111: X4 模式與 MAXCNT 對照 110: X4 模式與 INDX 對照 101: X2 模式與 MAXCNT 對照 100: X2 模式與 INDX 對照 001: 開始 16 位元 timer

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QEI

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  1. QEI QUADRATURE ENCODER INTERFACE (QEI) Ken Wang ~

  2. CNTERR: QESIDL: 0: 繼續動作 1: 閒置模式 UPDN : 0: timer向下計數 1: timer向上計數 QEIM<2:0> : QEI Mode Select bit 111: X4模式與MAXCNT對照 110: X4模式與INDX對照 101: X2模式與MAXCNT對照 100: X2模式與INDX對照 001: 開始16位元timer SWPAB: 0: 不交換 1: QEA與QEB交換 TQGATE: 觸發準位

  3. TQCKPS <1,0> : //11 = 1:256 prescale value //10 = 1:64 prescale value //01 = 1:8 prescale value //00 = 1:1 prescale value PRSRES: 0:不重置繼續計數 1:計數值重置 TQCS:選擇計數源 0:內頻 1:外頻 UDPN SRC: 0: timer計數方向由QEB控制 1: timer計數方向由UPDN控制 POSCNT: 16位元上/下數計數器 MAXCNT: 計數器的最大值

  4. 程 式 部 分 用訊號產生器當作輸入之命令

  5. #include <p30F4011.h> //呼叫p30F3011(IC)指令巨集 • #include <math.h> • unsigned int s=0,icount=0,qot=0; • unsigned int QEI_Old = 0 ; • unsigned int QEI_New = 0 ; • unsigned int QEI_Diff ; • _FWDT(WDT_OFF); • void Init_Timer1( void ) • { • T1CON = 0; • IFS0bits.T1IF = 0; • IPC0bits.T1IP = 7; • IEC0bits.T1IE = 1; • PR1 = XXXXX; // 20MHz/8/XXXXX=？KHz • T1CONbits.TCS = 0; • T1CONbits.TCKPS=X; //TCKPS<1:0>: Timer Input Clock Prescale Select bits • //11 = 1:256 prescale value • //10 = 1:64 prescale value • //01 = 1:8 prescale value • //00 = 1:1 prescale value • T1CONbits.TON=1; • }

  6. void IO_Initial( void ) • { • TRISB = 0x30; // 0b 0000 0000 0011 0000 // bit4.5當成輸入 • TRISE = 0x00; // E全部設為輸出 • } • void _ISR _T1Interrupt(void) • { • if(++icount==N) • { • QEI_Old = QEI_New ; • QEI_New=POSCNT; • if ( QEICONbits.UPDN ) // 馬達正轉時的計算 • { • if ( QEI_New >= QEI_Old ) // 計算單位時間內的旋轉數量 • QEI_Diff = QEI_New - QEI_Old ; • else // 溢位時的處理 • QEI_Diff = QEI_New + ( 65536 - QEI_Old ) ; • } icount=0; //將icount歸0 • qot+=QEI_Diff; //將Diff做的結果給qot做累加 • s++; • } • if(s==10) • { • s=0; //s歸0 • qot/=10; //qot累加十次後取平均值 • PORTE=qot; //從E port輸出 • qot=0; //qot歸0 • } • IFS0bits.T1IF = 0; //中斷關閉 • }

  7. void Qei_Initial(void) • { • QEICON=0x0700; //設定0000 0111 0000 0000 • POSCNT=0x0; //16位元計數初始值設定 • MAXCNT=0xffff; //設定計數器最大值65535 • QEICONbits.CNTERR=1; //設定啟動 • } • int main(void) • { • ADPCFG=0xffff; //設定為一般I/O腳位 • IO_Initial(); • Qei_Initial(); • Init_Timer1(); while(1); • } • 頻率計算:(訊號產生器頻率/Time頻率)*4

  8. 題目: • Time設定

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