Chen Wei Ting / Mbed 2 deprecated LSM9DS1_project_3

read encoder

Dependencies:   mbed

main.cpp@0:f2657b94ea70, 2018-07-31 (annotated)

Committer:
JJting
Date:
Tue Jul 31 12:18:02 2018 +0000
Revision:
0:f2657b94ea70
Child:
1:2f2a74337b77
20180731

Who changed what in which revision?

UserRevisionLine numberNew contents of line
JJting 0:f2657b94ea70 1 #include "mbed.h"
JJting 0:f2657b94ea70 2
JJting 0:f2657b94ea70 3 Serial uart(USBTX, USBRX);
JJting 0:f2657b94ea70 4 //Serial uart(D10,D2); // TX : D10 RX : D2 // blueteeth
JJting 0:f2657b94ea70 5 DigitalOut LED(A4); // check if the code is running
JJting 0:f2657b94ea70 6
JJting 0:f2657b94ea70 7 // timer
JJting 0:f2657b94ea70 8 Ticker timer1;
JJting 0:f2657b94ea70 9 float ITR_time1 = 10000.0; // unit：ms
JJting 0:f2657b94ea70 10
JJting 0:f2657b94ea70 11
JJting 0:f2657b94ea70 12 // encoder
JJting 0:f2657b94ea70 13 DigitalOut encoder_cs(D9);
JJting 0:f2657b94ea70 14 SPI spi_encoder(D11, D12, D13); // mosi, miso, sclk
JJting 0:f2657b94ea70 15 unsigned short encoder_value = 0;
JJting 0:f2657b94ea70 16 unsigned short angle = 0;
JJting 0:f2657b94ea70 17 unsigned short angle_old;
JJting 0:f2657b94ea70 18 unsigned short angle_init;
JJting 0:f2657b94ea70 19 int angle_dif;
JJting 0:f2657b94ea70 20 int a_dif;
JJting 0:f2657b94ea70 21 int Angle;
JJting 0:f2657b94ea70 22 unsigned short k = 0;
JJting 0:f2657b94ea70 23
JJting 0:f2657b94ea70 24 // uart_tx
JJting 0:f2657b94ea70 25 union splitter {
JJting 0:f2657b94ea70 26 short j;
JJting 0:f2657b94ea70 27 char C[2];
JJting 0:f2657b94ea70 28 // C[0] is lowbyte of j, C[1] is highbyte of j
JJting 0:f2657b94ea70 29 };
JJting 0:f2657b94ea70 30 char T[16] = {255,255,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
JJting 0:f2657b94ea70 31 int i = 0;
JJting 0:f2657b94ea70 32
JJting 0:f2657b94ea70 33 // function
JJting 0:f2657b94ea70 34 void init_encoder();
JJting 0:f2657b94ea70 35 void init_SPI();
JJting 0:f2657b94ea70 36 void init_UART();
JJting 0:f2657b94ea70 37 void init_TIMER();
JJting 0:f2657b94ea70 38 void timer1_ITR();
JJting 0:f2657b94ea70 39 void angle_measure();
JJting 0:f2657b94ea70 40 int angle_count(unsigned short,unsigned short);
JJting 0:f2657b94ea70 41 void uart_tx();
JJting 0:f2657b94ea70 42
JJting 0:f2657b94ea70 43
JJting 0:f2657b94ea70 44 int main()
JJting 0:f2657b94ea70 45 {
JJting 0:f2657b94ea70 46 LED = 1;
JJting 0:f2657b94ea70 47 wait_ms(500);
JJting 0:f2657b94ea70 48 // initial sensor
JJting 0:f2657b94ea70 49 init_encoder();
JJting 0:f2657b94ea70 50 init_SPI();
JJting 0:f2657b94ea70 51 // initial uart
JJting 0:f2657b94ea70 52 init_UART();
JJting 0:f2657b94ea70 53
JJting 0:f2657b94ea70 54 wait_ms(500);
JJting 0:f2657b94ea70 55 LED = 0;
JJting 0:f2657b94ea70 56
JJting 0:f2657b94ea70 57 init_TIMER();
JJting 0:f2657b94ea70 58
JJting 0:f2657b94ea70 59 while(1) {
JJting 0:f2657b94ea70 60 }
JJting 0:f2657b94ea70 61
JJting 0:f2657b94ea70 62 }
JJting 0:f2657b94ea70 63
JJting 0:f2657b94ea70 64 void init_encoder()
JJting 0:f2657b94ea70 65 {
JJting 0:f2657b94ea70 66 // encoder_cs = 1; // disable encoder
JJting 0:f2657b94ea70 67
JJting 0:f2657b94ea70 68 encoder_cs = 0; // Select the device by seting chip select low
JJting 0:f2657b94ea70 69 encoder_value = spi_encoder.write(0x00);
JJting 0:f2657b94ea70 70 angle_init = encoder_value >> 3;
JJting 0:f2657b94ea70 71 encoder_cs = 1; // Deselect the device
JJting 0:f2657b94ea70 72
JJting 0:f2657b94ea70 73 }
JJting 0:f2657b94ea70 74
JJting 0:f2657b94ea70 75 void init_SPI()
JJting 0:f2657b94ea70 76 {
JJting 0:f2657b94ea70 77 spi_encoder.format(16,3);
JJting 0:f2657b94ea70 78 spi_encoder.frequency(1000000); // 1MHz clock rate
JJting 0:f2657b94ea70 79 }
JJting 0:f2657b94ea70 80
JJting 0:f2657b94ea70 81 void init_UART()
JJting 0:f2657b94ea70 82 {
JJting 0:f2657b94ea70 83 uart.baud(115200);
JJting 0:f2657b94ea70 84 }
JJting 0:f2657b94ea70 85
JJting 0:f2657b94ea70 86 void init_TIMER()
JJting 0:f2657b94ea70 87 {
JJting 0:f2657b94ea70 88 timer1.attach_us(&timer1_ITR, ITR_time1);
JJting 0:f2657b94ea70 89 }
JJting 0:f2657b94ea70 90
JJting 0:f2657b94ea70 91 void timer1_ITR()
JJting 0:f2657b94ea70 92 {
JJting 0:f2657b94ea70 93 angle_measure();
JJting 0:f2657b94ea70 94 // angle_count();
JJting 0:f2657b94ea70 95 uart_tx();
JJting 0:f2657b94ea70 96 }
JJting 0:f2657b94ea70 97
JJting 0:f2657b94ea70 98 void angle_measure()
JJting 0:f2657b94ea70 99 {
JJting 0:f2657b94ea70 100 encoder_cs = 0; // Select the device by seting chip select low
JJting 0:f2657b94ea70 101 encoder_value = spi_encoder.write(0x00);
JJting 0:f2657b94ea70 102 angle = encoder_value >> 3;
JJting 0:f2657b94ea70 103 encoder_cs = 1; // Deselect the device
JJting 0:f2657b94ea70 104
JJting 0:f2657b94ea70 105 if (k == 0)
JJting 0:f2657b94ea70 106 {
JJting 0:f2657b94ea70 107 angle_dif = angle_count(angle, angle_init);
JJting 0:f2657b94ea70 108 Angle = angle_init + angle_dif;
JJting 0:f2657b94ea70 109 angle_old = angle;
JJting 0:f2657b94ea70 110 k++;
JJting 0:f2657b94ea70 111 // angle_dif = angle_count();
JJting 0:f2657b94ea70 112 // Angle = angle_init + angle_dif;
JJting 0:f2657b94ea70 113 // angle_old = angle;
JJting 0:f2657b94ea70 114 // k++;
JJting 0:f2657b94ea70 115 }
JJting 0:f2657b94ea70 116 else
JJting 0:f2657b94ea70 117 {
JJting 0:f2657b94ea70 118 angle_dif = angle_count(angle, angle_old);
JJting 0:f2657b94ea70 119 Angle = Angle + angle_dif;
JJting 0:f2657b94ea70 120 angle_old = angle;
JJting 0:f2657b94ea70 121 }
JJting 0:f2657b94ea70 122 }
JJting 0:f2657b94ea70 123
JJting 0:f2657b94ea70 124 int angle_count(unsigned short now,unsigned short old)
JJting 0:f2657b94ea70 125 {
JJting 0:f2657b94ea70 126 a_dif = now - old;
JJting 0:f2657b94ea70 127 if (a_dif > 4096/2)
JJting 0:f2657b94ea70 128 a_dif = -(4096 - a_dif);
JJting 0:f2657b94ea70 129 else if (a_dif < -4096/2)
JJting 0:f2657b94ea70 130 a_dif = 4096 + a_dif;
JJting 0:f2657b94ea70 131 else
JJting 0:f2657b94ea70 132 a_dif = a_dif;
JJting 0:f2657b94ea70 133
JJting 0:f2657b94ea70 134 return a_dif;
JJting 0:f2657b94ea70 135 }
JJting 0:f2657b94ea70 136
JJting 0:f2657b94ea70 137 void uart_tx()
JJting 0:f2657b94ea70 138 {
JJting 0:f2657b94ea70 139 splitter s1;
JJting 0:f2657b94ea70 140 splitter s2;
JJting 0:f2657b94ea70 141 splitter s3;
JJting 0:f2657b94ea70 142 splitter s4;
JJting 0:f2657b94ea70 143 splitter s5;
JJting 0:f2657b94ea70 144 splitter s6;
JJting 0:f2657b94ea70 145 splitter s7;
JJting 0:f2657b94ea70 146
JJting 0:f2657b94ea70 147 s1.j = angle;
JJting 0:f2657b94ea70 148 s2.j = Angle;
JJting 0:f2657b94ea70 149 s3.j = 2;
JJting 0:f2657b94ea70 150 s4.j = 3;
JJting 0:f2657b94ea70 151 s5.j = 1;
JJting 0:f2657b94ea70 152 s6.j = 2;
JJting 0:f2657b94ea70 153 s7.j = 3;
JJting 0:f2657b94ea70 154
JJting 0:f2657b94ea70 155 T[2] = s1.C[0];
JJting 0:f2657b94ea70 156 T[3] = s1.C[1];
JJting 0:f2657b94ea70 157 T[4] = s2.C[0];
JJting 0:f2657b94ea70 158 T[5] = s2.C[1];
JJting 0:f2657b94ea70 159 T[6] = s3.C[0];
JJting 0:f2657b94ea70 160 T[7] = s3.C[1];
JJting 0:f2657b94ea70 161 T[8] = s4.C[0];
JJting 0:f2657b94ea70 162 T[9] = s4.C[1];
JJting 0:f2657b94ea70 163 T[10] = s5.C[0];
JJting 0:f2657b94ea70 164 T[11] = s5.C[1];
JJting 0:f2657b94ea70 165 T[12] = s6.C[0];
JJting 0:f2657b94ea70 166 T[13] = s6.C[1];
JJting 0:f2657b94ea70 167 T[14] = s7.C[0];
JJting 0:f2657b94ea70 168 T[15] = s7.C[1];
JJting 0:f2657b94ea70 169
JJting 0:f2657b94ea70 170 while(1) {
JJting 0:f2657b94ea70 171 if (uart.writable() == 1) {
JJting 0:f2657b94ea70 172 uart.putc(T[i]);
JJting 0:f2657b94ea70 173 i++;
JJting 0:f2657b94ea70 174 }
JJting 0:f2657b94ea70 175 if (i >= (sizeof(T)-1)) {
JJting 0:f2657b94ea70 176 i = 0;
JJting 0:f2657b94ea70 177 break;
JJting 0:f2657b94ea70 178 }
JJting 0:f2657b94ea70 179 }
JJting 0:f2657b94ea70 180 }