Chen Wei Ting / Mbed 2 deprecated system_ID

ver1

Dependencies:   MX28 mbed

encoder.cpp@0:762ec6dc5696, 2018-08-29 (annotated)

Committer:
JJting
Date:
Wed Aug 29 07:30:11 2018 +0000
Revision:
0:762ec6dc5696
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
JJting 0:762ec6dc5696 1 #include "mbed.h"
JJting 0:762ec6dc5696 2 #include "encoder.h"
JJting 0:762ec6dc5696 3
JJting 0:762ec6dc5696 4 DigitalOut encoder_cs(D9);
JJting 0:762ec6dc5696 5 SPI spi_encoder(D11, D12, D13); // mosi, miso, sclk
JJting 0:762ec6dc5696 6
JJting 0:762ec6dc5696 7 unsigned short encoder_value;
JJting 0:762ec6dc5696 8 unsigned short encoder_value_1;
JJting 0:762ec6dc5696 9 unsigned short encoder_value_2;
JJting 0:762ec6dc5696 10 unsigned short angle;
JJting 0:762ec6dc5696 11 unsigned short angle_old;
JJting 0:762ec6dc5696 12 int angle_dif;
JJting 0:762ec6dc5696 13 int a_dif;
JJting 0:762ec6dc5696 14 int Angle = 0;
JJting 0:762ec6dc5696 15 unsigned short k = 0;
JJting 0:762ec6dc5696 16
JJting 0:762ec6dc5696 17 void init_SPI_encoder()
JJting 0:762ec6dc5696 18 {
JJting 0:762ec6dc5696 19 spi_encoder.format(8,3);
JJting 0:762ec6dc5696 20 spi_encoder.frequency(1200000); // 1.125MHz clock rate
JJting 0:762ec6dc5696 21 }
JJting 0:762ec6dc5696 22
JJting 0:762ec6dc5696 23 void init_encoder()
JJting 0:762ec6dc5696 24 {
JJting 0:762ec6dc5696 25 encoder_cs = 1; // high：disable the device
JJting 0:762ec6dc5696 26 }
JJting 0:762ec6dc5696 27
JJting 0:762ec6dc5696 28 void angle_measure()
JJting 0:762ec6dc5696 29 {
JJting 0:762ec6dc5696 30 encoder_cs = 0; // Select the device by seting chip select low
JJting 0:762ec6dc5696 31 encoder_value_1 = spi_encoder.write(0x00);
JJting 0:762ec6dc5696 32 encoder_value_2 = spi_encoder.write(0x00);
JJting 0:762ec6dc5696 33 encoder_value = (encoder_value_1 << 8) | encoder_value_2;
JJting 0:762ec6dc5696 34 angle = encoder_value >> 3;
JJting 0:762ec6dc5696 35 encoder_cs = 1; // Deselect the device
JJting 0:762ec6dc5696 36 // encoder_value = spi_encoder.write(0x00);
JJting 0:762ec6dc5696 37 // angle = encoder_value >> 3;
JJting 0:762ec6dc5696 38 // encoder_cs = 1; // Deselect the device
JJting 0:762ec6dc5696 39
JJting 0:762ec6dc5696 40 if (k == 0)
JJting 0:762ec6dc5696 41 {
JJting 0:762ec6dc5696 42 Angle = 0;
JJting 0:762ec6dc5696 43 angle_old = angle;
JJting 0:762ec6dc5696 44 k++;
JJting 0:762ec6dc5696 45 }
JJting 0:762ec6dc5696 46 else
JJting 0:762ec6dc5696 47 {
JJting 0:762ec6dc5696 48 angle_dif = angle_count(angle, angle_old);
JJting 0:762ec6dc5696 49 Angle = Angle + angle_dif;
JJting 0:762ec6dc5696 50 angle_old = angle;
JJting 0:762ec6dc5696 51 }
JJting 0:762ec6dc5696 52
JJting 0:762ec6dc5696 53 }
JJting 0:762ec6dc5696 54
JJting 0:762ec6dc5696 55 int angle_count(unsigned short now,unsigned short old)
JJting 0:762ec6dc5696 56 {
JJting 0:762ec6dc5696 57 a_dif = now - old;
JJting 0:762ec6dc5696 58 if (a_dif > 4096/2)
JJting 0:762ec6dc5696 59 a_dif = -(4096 - a_dif);
JJting 0:762ec6dc5696 60 else if (a_dif < -4096/2)
JJting 0:762ec6dc5696 61 a_dif = 4096 + a_dif;
JJting 0:762ec6dc5696 62 else
JJting 0:762ec6dc5696 63 a_dif = a_dif;
JJting 0:762ec6dc5696 64
JJting 0:762ec6dc5696 65 return a_dif;
JJting 0:762ec6dc5696 66 }