Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
PositionSensor/PositionSensor.cpp
- Committer:
- benkatz
- Date:
- 2018-03-02
- Revision:
- 36:d88fd41f60a6
- Parent:
- 35:69b24894c11d
- Child:
- 37:c0f352d6e8e3
File content as of revision 36:d88fd41f60a6:
#include "mbed.h"
#include "PositionSensor.h"
//#include "offset_lut.h"
//#include <math.h>
PositionSensorAM5147::PositionSensorAM5147(int CPR, float offset, int ppairs){
//_CPR = CPR;
_CPR = CPR;
_ppairs = ppairs;
ElecOffset = offset;
rotations = 0;
spi = new SPI(PC_12, PC_11, PC_10);
spi->format(16, 1); // mbed v>127 breaks 16-bit spi, so transaction is broken into 2 8-bit words
spi->frequency(25000000);
cs = new DigitalOut(PA_15);
cs->write(1);
readAngleCmd = 0xffff;
MechOffset = 0;
modPosition = 0;
oldModPosition = 0;
oldVel = 0;
raw = 0;
}
void PositionSensorAM5147::Sample(){
cs->write(0);
raw = spi->write(readAngleCmd);
raw &= 0x3FFF; //Extract last 14 bits
cs->write(1);
int off_1 = offset_lut[raw>>7];
int off_2 = offset_lut[((raw>>7)+1)%128];
int off_interp = off_1 + ((off_2 - off_1)*(raw - ((raw>>7)<<7))>>7); // Interpolate between lookup table entries
int angle = raw + off_interp; // Correct for nonlinearity with lookup table from calibration
if(angle - old_counts > _CPR/2){
rotations -= 1;
}
else if (angle - old_counts < -_CPR/2){
rotations += 1;
}
old_counts = angle;
oldModPosition = modPosition;
modPosition = ((6.28318530718f * ((float) angle))/ (float)_CPR);
position = (6.28318530718f * ((float) angle+(_CPR*rotations)))/ (float)_CPR;
MechPosition = position - MechOffset;
float elec = ((6.28318530718f/(float)_CPR) * (float) ((_ppairs*angle)%_CPR)) + ElecOffset;
if(elec < 0) elec += 6.28318530718f;
else if(elec > 6.28318530718f) elec -= 6.28318530718f ;
ElecPosition = elec;
float vel;
if(modPosition<.1f && oldModPosition>6.1f){
vel = (modPosition - oldModPosition + 6.28318530718f)*40000.0f;
}
else if(modPosition>6.1f && oldModPosition<0.1f){
vel = (modPosition - oldModPosition - 6.28318530718f)*40000.0f;
}
else{
vel = (modPosition-oldModPosition)*40000.0f;
}
int n = 40;
float sum = vel;
for (int i = 1; i < (n); i++){
velVec[n - i] = velVec[n-i-1];
sum += velVec[n-i];
}
velVec[0] = vel;
MechVelocity = sum/(float)n;
ElecVelocity = MechVelocity*_ppairs;
ElecVelocityFilt = 0.99f*ElecVelocityFilt + 0.01f*ElecVelocity;
}
int PositionSensorAM5147::GetRawPosition(){
return raw;
}
float PositionSensorAM5147::GetMechPosition(){
return MechPosition;
}
float PositionSensorAM5147::GetElecPosition(){
return ElecPosition;
}
float PositionSensorAM5147::GetMechVelocity(){
return MechVelocity;
}
void PositionSensorAM5147::ZeroPosition(){
rotations = 0;
MechOffset = 0;
Sample();
MechOffset = GetMechPosition();
}
void PositionSensorAM5147::SetElecOffset(float offset){
ElecOffset = offset;
}
int PositionSensorAM5147::GetCPR(){
return _CPR;
}
void PositionSensorAM5147::WriteLUT(int new_lut[128]){
memcpy(offset_lut, new_lut, sizeof(offset_lut));
}
PositionSensorEncoder::PositionSensorEncoder(int CPR, float offset, int ppairs) {
_ppairs = ppairs;
_CPR = CPR;
_offset = offset;
MechPosition = 0;
out_old = 0;
oldVel = 0;
raw = 0;
// Enable clock for GPIOA
__GPIOA_CLK_ENABLE(); //equivalent from hal_rcc.h
GPIOA->MODER |= GPIO_MODER_MODER6_1 | GPIO_MODER_MODER7_1 ; //PA6 & PA7 as Alternate Function /*!< GPIO port mode register, Address offset: 0x00 */
GPIOA->OTYPER |= GPIO_OTYPER_OT_6 | GPIO_OTYPER_OT_7 ; //PA6 & PA7 as Inputs /*!< GPIO port output type register, Address offset: 0x04 */
GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR6 | GPIO_OSPEEDER_OSPEEDR7 ; //Low speed /*!< GPIO port output speed register, Address offset: 0x08 */
GPIOA->PUPDR |= GPIO_PUPDR_PUPDR6_1 | GPIO_PUPDR_PUPDR7_1 ; //Pull Down /*!< GPIO port pull-up/pull-down register, Address offset: 0x0C */
GPIOA->AFR[0] |= 0x22000000 ; //AF02 for PA6 & PA7 /*!< GPIO alternate function registers, Address offset: 0x20-0x24 */
GPIOA->AFR[1] |= 0x00000000 ; //nibbles here refer to gpio8..15 /*!< GPIO alternate function registers, Address offset: 0x20-0x24 */
// configure TIM3 as Encoder input
// Enable clock for TIM3
__TIM3_CLK_ENABLE();
TIM3->CR1 = 0x0001; // CEN(Counter ENable)='1' < TIM control register 1
TIM3->SMCR = TIM_ENCODERMODE_TI12; // SMS='011' (Encoder mode 3) < TIM slave mode control register
TIM3->CCMR1 = 0x1111; // CC1S='01' CC2S='01' < TIM capture/compare mode register 1, maximum digital filtering
TIM3->CCMR2 = 0x0000; // < TIM capture/compare mode register 2
TIM3->CCER = 0x0011; // CC1P CC2P < TIM capture/compare enable register
TIM3->PSC = 0x0000; // Prescaler = (0+1) < TIM prescaler
TIM3->ARR = CPR; // IM auto-reload register
TIM3->CNT = 0x000; //reset the counter before we use it
// Extra Timer for velocity measurement
__TIM2_CLK_ENABLE();
TIM3->CR2 = 0x030; //MMS = 101
TIM2->PSC = 0x03;
//TIM2->CR2 |= TIM_CR2_TI1S;
TIM2->SMCR = 0x24; //TS = 010 for ITR2, SMS = 100 (reset counter at edge)
TIM2->CCMR1 = 0x3; // CC1S = 11, IC1 mapped on TRC
//TIM2->CR2 |= TIM_CR2_TI1S;
TIM2->CCER |= TIM_CCER_CC1P;
//TIM2->CCER |= TIM_CCER_CC1NP;
TIM2->CCER |= TIM_CCER_CC1E;
TIM2->CR1 = 0x01; //CEN, enable timer
TIM3->CR1 = 0x01; // CEN
ZPulse = new InterruptIn(PC_4);
ZSense = new DigitalIn(PC_4);
//ZPulse = new InterruptIn(PB_0);
//ZSense = new DigitalIn(PB_0);
ZPulse->enable_irq();
ZPulse->rise(this, &PositionSensorEncoder::ZeroEncoderCount);
//ZPulse->fall(this, &PositionSensorEncoder::ZeroEncoderCountDown);
ZPulse->mode(PullDown);
flag = 0;
//ZTest = new DigitalOut(PC_2);
//ZTest->write(1);
}
void PositionSensorEncoder::Sample(){
}
float PositionSensorEncoder::GetMechPosition() { //returns rotor angle in radians.
int raw = TIM3->CNT;
float unsigned_mech = (6.28318530718f/(float)_CPR) * (float) ((raw)%_CPR);
return (float) unsigned_mech;// + 6.28318530718f* (float) rotations;
}
float PositionSensorEncoder::GetElecPosition() { //returns rotor electrical angle in radians.
int raw = TIM3->CNT;
float elec = ((6.28318530718f/(float)_CPR) * (float) ((_ppairs*raw)%_CPR)) - _offset;
if(elec < 0) elec += 6.28318530718f;
return elec;
}
float PositionSensorEncoder::GetMechVelocity(){
float out = 0;
float rawPeriod = TIM2->CCR1; //Clock Ticks
int currentTime = TIM2->CNT;
if(currentTime > 2000000){rawPeriod = currentTime;}
float dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f; // +/- 1
float meas = dir*180000000.0f*(6.28318530718f/(float)_CPR)/rawPeriod;
if(isinf(meas)){ meas = 1;}
out = meas;
//if(meas == oldVel){
// out = .9f*out_old;
// }
oldVel = meas;
out_old = out;
int n = 16;
float sum = out;
for (int i = 1; i < (n); i++){
velVec[n - i] = velVec[n-i-1];
sum += velVec[n-i];
}
velVec[0] = out;
return sum/(float)n;
}
float PositionSensorEncoder::GetElecVelocity(){
return _ppairs*GetMechVelocity();
}
void PositionSensorEncoder::ZeroEncoderCount(void){
if (ZSense->read() == 1 & flag == 0){
if (ZSense->read() == 1){
GPIOC->ODR ^= (1 << 4);
TIM3->CNT = 0x000;
//state = !state;
//ZTest->write(state);
GPIOC->ODR ^= (1 << 4);
//flag = 1;
}
}
}
void PositionSensorEncoder::ZeroPosition(void){
}
void PositionSensorEncoder::ZeroEncoderCountDown(void){
if (ZSense->read() == 0){
if (ZSense->read() == 0){
GPIOC->ODR ^= (1 << 4);
flag = 0;
float dir = -2.0f*(float)(((TIM3->CR1)>>4)&1)+1.0f;
if(dir != dir){
dir = dir;
rotations += dir;
}
GPIOC->ODR ^= (1 << 4);
}
}
}
void PositionSensorEncoder::SetElecOffset(float offset){
}
int PositionSensorEncoder::GetRawPosition(void){
return 0;
}
int PositionSensorEncoder::GetCPR(){
return _CPR;
}
void PositionSensorEncoder::WriteLUT(int new_lut[128]){
memcpy(offset_lut, new_lut, sizeof(offset_lut));
}