Revision 0:00c56a9c6dee, committed 2016-03-05

Comitter:

dhaldane

Date:

Sat Mar 05 00:09:45 2016 +0000

Commit message:

Driver codes;

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/enc.cpp	Sat Mar 05 00:09:45 2016 +0000
@@ -0,0 +1,105 @@
+#include "enc.h"
+
+enc::enc(PinName mosi, PinName miso, PinName sck, PinName cs) : m_spi(mosi, miso, sck), csl(cs){
+    ushort zpos = 2228; // est. 8/6/2015 1773
+    ushort zhold;
+    m_spi.format(16, 1);
+    m_spi.frequency(50000);
+    csl=1;
+    wait(0.05);
+
+
+    write_spi(0x0019, 0); //SETTINGS2
+    write_spi(0x001D, 0);
+    write_spi(0x0018, 0); //SETTINGS1
+    write_spi(0x0018, 0);
+    
+    zhold = zpos >> 6; //8MSB of zero position
+    write_spi(0x0016, 0);
+    write_spi(zhold, 0);
+    
+    zhold = zpos & 0x003F; //6 LSB of zero position
+    write_spi(0x0017, 0);
+    write_spi(zhold, 0);   
+    
+    enc_pos.pos = 0;
+    enc_pos.oticks = 0;
+    enc_pos.offset = 0;
+    enc_pos.calibPos = 0;
+    }
+    
+enc::~enc(){
+ 
+}
+
+unsigned int enc::cal_state(){
+    return enc_pos.pos;
+}
+
+void enc::set_offset(){
+    enc_pos.offset = ams_read();
+}
+
+ushort enc::write_spi(ushort reg, u8 rw){
+    ushort data;
+    reg = reg | rw << 14;
+    reg = reg | par(reg);
+    csl=0;
+    data = m_spi.write(reg);
+    csl=1;
+    wait(0.00001);
+    return data;
+    
+}
+
+ushort enc::read_spi(ushort reg){
+    ushort data;
+    reg = reg | 1 << 14;
+    reg = reg | par(reg);
+    write_spi(reg, 1);
+    data = write_spi(0x0000, 1);
+    return data;  
+}
+
+/*!
+*****************************************************************************
+* Calculate even parity of a 16 bit unsigned integer
+*
+* This function is used by the SPI interface to calculate the even parity
+* of the data which will be sent via SPI to the encoder.
+*
+* \param[in] value : 16 bit unsigned integer whose parity shall be calculated
+*
+* \return : Even parity
+*
+*****************************************************************************
+*/
+ushort enc::par(ushort value)
+{
+    u8 cnt = 0;
+    u8 i;
+ 
+    for (i = 0; i < 16; i++)
+    {
+        if (value & 0x1)
+        {
+            cnt++;
+        }
+        value >>= 1;
+    }
+    cnt = cnt & 0x1;
+    return cnt << 15;
+}
+
+void enc::update_pos(){
+    enc_pos.pos = ams_read();
+}
+
+unsigned int enc::ams_read() {
+    unsigned int enc_data;
+
+    enc_data = read_spi(0x3FFE);
+    read_spi(0x0001);
+        
+    return enc_data & 0x3FFF;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/enc.h	Sat Mar 05 00:09:45 2016 +0000
@@ -0,0 +1,39 @@
+#include "mbed.h"
+#define u8 unsigned char
+#define u16 unsigned int
+#define ubyte unsigned char
+#define ushort unsigned short int
+#define bit unsigned char
+typedef struct {
+    unsigned int pos; // raw reading from sensor 14 bits
+    long oticks;  // revolution counter
+    unsigned int calibPos;  // 0 to 2pi, converted to 16 bits
+    unsigned int offset; // initial reading on setup - relative zero position
+} EncObj; 
+
+class enc
+{
+public:
+    //Connect over i2c
+    enc(PinName mosi, PinName miso, PinName sck, PinName cs);
+    //Destroy instance
+    ~enc();
+    unsigned int  ams_read();
+    void update_pos();
+    void set_offset();
+    unsigned int cal_state(); //Calibrated stat
+    static ushort par(ushort value);
+    ushort write_spi(ushort reg, u8 rw);
+    ushort read_spi(ushort reg);
+    EncObj enc_pos;
+    
+private:
+    SPI m_spi;
+    DigitalOut csl;
+
+};
+
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Mar 05 00:09:45 2016 +0000
@@ -0,0 +1,23 @@
+#include "mbed.h"
+#include "enc.h"
+
+Ticker RTI;
+DigitalOut myled(LED1);
+Serial pc(USBTX, USBRX); // tx, rx
+enc crankPos(p5,p6,p7,p8);
+
+
+void get_state(){
+    crankPos.update_pos();
+}
+
+int main() {    
+    RTI.attach(&get_state, 0.01);
+    while(1) {
+        myled = 1;
+        wait(0.05);
+        pc.printf("Encoder: %u                             \r\n", crankPos.cal_state());
+        myled = 0;
+        wait(0.05);
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sat Mar 05 00:09:45 2016 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/7e07b6fb45cf
\ No newline at end of file