A program to monitor some parameters for a motor
Dependencies: mbed-dev BufferSerial
Thanks to David Lowe for https://developer.mbed.org/users/gregeric/code/Nucleo_Hello_Encoder/ which I adapted for the use of TIM2 32bit timer as an encoder reader on the Nucleo L432KC board.
main.cpp
- Committer:
- tonnyleonard
- Date:
- 2017-06-22
- Revision:
- 23:5cd74e296f59
- Parent:
- 22:9bba1417e4a4
File content as of revision 23:5cd74e296f59:
/* * Nucleo STM32F4(or L4) quadrature decoder, ADCs and DACs * with serial communication over the USB virtual serial port * Developed for Elliptec X15 piezoelectric motor control, on a L432KC board * * Using STM32's counter peripherals to interface rotary encoders. * Encoders are supported on F4xx's TIM1,2,3,4,5. TIM2 & TIM5 have 32bit count, * others 16bit. * Take into account that on F4xx Mbed uses TIM5 for system timer, SPI needs TIM1, * others are used for PWM. * Check your platform's PeripheralPins.c & PeripheralNames.h if you need * both PWM & encoders. This project does not use PWM. * * On L432KC, for example, only TIM2 has 32bit count, others have 16bit. * However, mbed has TIM2 assigned by default to the system ticker * For L432KC to work with TIM2 encoder input one needs to reassign * the system ticker from TIM2 to TIM7, for example, * in mbed-dev/targets/TARGET_STM/TARGET_STM32L4/TARGET_STM32L432xC/device/hal_tick.h * * Edit HAL_TIM_Encoder_MspInitFx(Lx).cpp to suit your mcu & board's available * pinouts & pullups/downs. * * Thanks to: * David Lowe (for the quadrature encoder code) * https://developer.mbed.org/users/gregeric/code/Nucleo_Hello_Encoder/ * * And Frederic Blanc * https://developer.mbed.org/users/fblanc/code/AnalogIn_Diff/ * * And Eric Lewiston / STM32L4xx_HAL_Driver * https://developer.mbed.org/users/EricLew/code/STM32L4xx_HAL_Driver/docs/tip/group__ADC__LL__EF__Configuration__Channels.html * * References: * http://www.st.com/resource/en/datasheet/stm32l432kc.pdf * https://developer.mbed.org/platforms/ST-Nucleo-L432KC/ * http://www.st.com/web/en/resource/technical/document/application_note/DM00042534.pdf * http://www.st.com/web/en/resource/technical/document/datasheet/DM00102166.pdf * * Tonny-Leonard Farauanu, 2017 */ #include "mbed.h" #include "Encoder.h" //Defining the timer and its coresponding encoder TIM_HandleTypeDef timer2; TIM_Encoder_InitTypeDef encoder1; //Timer to be used for the speed computation function Timer timer1; //The input for the encoder's index channel InterruptIn event(PA_8); //LED1 to signal USB serial RX interrupt reading DigitalOut led1(LED1); //LED2 to signal the encoder's index impulses //only for feedback, to calibrate the position //of the AVAGO encoder with respect to the shaft DigitalOut led2(PB_4); //Relay port to power on and off the Digitally Controlled Power Source (DCPS) DigitalOut relay1(PB_5); //Defining the ADCs //For reading the Phase Comparator output AnalogIn adc1(PA_3); //ADC1_IN8 //For reading the DCPS output AnalogIn adc2(PA_4); //ADC1_IN9 //For reading the current value from the shunt monitor AnalogIn adc3(PA_6); //ADC1_IN11 //Defining the DAC for the input of DCPS //(DCPS - Digitally Controlled Power Source) //DAC1_OUT2 on pin PA_5 is at least twices as fast as DAC1_OUT1 on pin PA_4 AnalogOut dac1(PA_5); // DAC1_OUT2 //Defining the serial object to be used for communicating with Raspi Serial raspi(USBTX, USBRX); //Counter for the absolute position from start int32_t count1 = 0; //Counter for the index passes volatile int32_t count2 = 0; //Records the wheel offset position to the index volatile int32_t count3 = 0; //Counter recording absolute position at last index pulse volatile int32_t count4 = 0; //Used to filter the first index pulse, so that the offset position //to the index may be recorded volatile bool adjustOffset = false; //Last data written to dac1 (using subunitary values) float dac_val = 0.0; //Array with adc1, adc2 & adc3 correction addition, //experimentally determined (hardware offset voltage dependent) const float adc_corr[] = { 0, 0.022f, 0.022f, 0.022f}; //Enable ADC reading and printing to the serial interface bool adc_en = true; //Enables speed computing and printing to the serial interface bool speed_en = true; //Enable position reading and printing to the serial interface bool pos_en = true; //Enable alternative position computation and printing to the serial interface, //relative to the encoder index pulses counter bool posIndex_en = true; //Function invoked by the encoder's index interrupt pulses //It counts the index pulses, incrementing or decrementing the number, //and registers the offset position of the wheel at start in count3; //The index counter is used to correct possible reading errors of the //encoder's counter //led2 is used for visual feedback. void atint() { count4 =__HAL_TIM_GET_COUNTER(&timer2); if (__HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2)) { if (count2 == 0 && adjustOffset == false) { //catch first index pulse count3 = count4; adjustOffset = true; } count2--; led2 =!led2; } else { if (count2 == 0 && adjustOffset == false) { //catch first index pulse count3 = count4; adjustOffset = true; } count2++; led2 =!led2; } } //Function for adaptive speed computation float speedRead() { //counter for the waiting time window uint16_t i = 0; //sample time for speed computation uint32_t deltaT; //Computer speed float speed; //First and second registered position int32_t pos1; int32_t pos2; //position difference to be used for speed computation int32_t pos; //Direction of rotation, read from the encoder, for the first //and the second registered positions int8_t sens1; int8_t sens2; timer1.start(); pos1=__HAL_TIM_GET_COUNTER(&timer2); sens1 = __HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2); //Minumum waiting time for this project would be 100 microseconds, //for 10 kHz quadrature frequency. We will set it 100 times longer //wait_ms(10); // Avoiding wait(), since it uses interrupts and timing here // is not critical. This takes 10 ms, if not interrupted for (uint32_t j=0; j<199950; j++) {} pos2=__HAL_TIM_GET_COUNTER(&timer2); sens2 = __HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2); //The speed computation method adapts to slow/fast speeds, in order to //optimize the rapport between computation precision and time windows size while (pos2 == pos1 && i<9) { // The accepted max delay time is 0.1 seconds //wait_ms(10); // Avoiding wait(), since it uses interrupts and timing here // is not critical. This takes 10 ms, if not interrupted for (uint32_t j=0; j<199950; j++) {} i++; pos2=__HAL_TIM_GET_COUNTER(&timer2); sens2 = __HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2); } pos2=__HAL_TIM_GET_COUNTER(&timer2); sens2 = __HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2); timer1.stop(); deltaT = timer1.read_us(); timer1.reset(); if (sens1 == sens2) { pos = pos2 - pos1; } else { printf("E:Speed computation error, change of direction between readings!\n"); } if (deltaT > 0) { //speed computation in rot/s speed = ((float) pos)*125.f/((float) deltaT); // (pulses/us)*1000000/8000 -> rot/s } else { printf("E:Error, time interval not greater than zero, speed not calculated!\n"); } return speed; } //Function attached to the serial RX interrupt event, it parses //the serial messages and invoques the corresponding commands void readData(void) { led1 = 1; char message[15]; if (raspi.readable()) { // Signalling the beginning of serial read int i = 0; bool rx = true; while(rx && i<14) { message[i] = raspi.getc(); if (message[i] == '\r') { message[i] = NULL; rx = false; } i++; } //Message received printed for debugging //printf("M:%d %s\n", strlen(message), message); int p1 = 0; if (strcmp(message, "adcOn") == 0) { adc_en = true; printf("M:ADC true\n"); } else if (strcmp(message, "adcOff") == 0) { adc_en = false; printf("M:ADC false\n"); } else if (p1=strstr(message, "v=") != NULL) { //Writing the dac1 value read from serial //The DCPS has 1V offset, so we have to remove it dac_val = (atof(message+p1+1)-1.f)/15.51; dac1.write(dac_val); } else if (strcmp(message, "reset") == 0) { //encoder related counters reset command TIM2->CNT = 0x0000; count1 = 0; count2 = 0; count3 = 0; count4 = 0; adjustOffset = false; printf("M:Encoder counters reset!\n"); } else if (strcmp(message, "powerOn") == 0) { //command to power on the DCPS relay1.write(1); printf("M:DCPS on\n"); } else if (strcmp(message, "powerOff") == 0) { //command to power off the DCPS relay1.write(0); printf("M:DCPS off\n"); } else if (strcmp(message, "posOn") == 0) { //command to enable the encoder position notification pos_en = true; printf("M:Position notification enabled\n"); } else if (strcmp(message, "posOff") == 0) { //command to disable the encoder position notification pos_en = false; printf("M:Position notification disabled\n"); } else if (strcmp(message, "posIndexOn") == 0) { //command to enable the index related encoder position notification posIndex_en = true; printf("M:Index related position notification enabled\n"); } else if (strcmp(message, "posIndexOff") == 0) { //command to disable the index related encoder position notification posIndex_en = false; printf("M:Index related position notification disabled\n"); } else if (strcmp(message, "speedOn") == 0) { //command to enable speed computation and notification speed_en = true; printf("M:Speed enabled\n"); } else if (strcmp(message, "speedOff") == 0) { //command to disable speed computation and notification speed_en = false; printf("M:Speed disabled\n"); } } //Signalling the end of searial read led1 = 0; } //Function to compute the average of 1000 ADC readings //Current intensity measurement should be as precise //as possible, the time delay introduced my multiplying //the readings is tolerable for this project float ADC_read(AnalogIn adc) { float Voltage; float Voltage_total = 0.0; // Voltage is summed then averaged for (int i=0; i<1000; i++) { // do 1000 readings Voltage = adc.read(); Voltage_total = Voltage_total+ Voltage; } Voltage = Voltage_total/1000.f; return Voltage; } //The main function int main() { //Make sure the DCPS is off relay1.write(0); //Set the DCPS output to (0.32x3.3)x4.7+1 = ~6V //These parameters are set for DCPS on load dac1.write(0.32); //counting on both A&B inputs (A at PA0, B at PA1), 4 ticks per cycle, //full 32-bit count //For L432KC to work with TIM2 one needs to reassign the system ticker //from TIM2 to TIM7 in TARGET/../device/hal_tick.h\ //Initialise encoder EncoderInit(&encoder1, &timer2, TIM2, 0xffffffff, TIM_ENCODERMODE_TI12); //Define function to call for interrupt event rise //This is triggered by the encoder's index pulses //and it resets the encoder counter event.rise(&atint); //Set serial baud rate raspi.baud(921600); //Attach functin to call for serial interrupt event //The wait() function ensures that not false serial RX //interrupt is triggered at power up, because of initial //serial port install by the Raspi OS wait(1); raspi.attach(&readData, Serial::RxIrq); //Message to mark the initialisation of the program printf("M:STM HAL encoder with ADC and DAC\n"); printf("M:Running at %u MHz\n", HAL_RCC_GetSysClockFreq()/1000000); //The main loop while(1) { //Variable for the direction of the counter int8_t dir1; //Prints the timestamp in miliseconds printf("T:%u", us_ticker_read()/1000); if (pos_en) { //It gets the position and the direction of the encoder count1=__HAL_TIM_GET_COUNTER(&timer2); dir1 = __HAL_TIM_IS_TIM_COUNTING_DOWN(&timer2); printf("P:%ldD:%sC:%d", count1, dir1==0 ? "+":"-", count2); if (posIndex_en) { if (count2 > 1) { printf("Pi:%ld", (count1-count4) + (count2-1)*8000 + count3); } else if (count2 < -1) { printf("Pi:%ld", (count1-count4) + (count2+1)*8000 + count3); } else { printf("Pi:%ld", (count1-count4) + count3); } } } if (speed_en) { //Print speed in rot/s printf("S:%.3f%", speedRead()); } if (adc_en) { //Print phase shift in Degrees, DCPS output voltage in Volts // and current intensity in Ampers // The dividing factors are hardware dependant printf("F:%3.3fU:%3.3fI:%3.3f", (3.3f*ADC_read(adc1)+adc_corr[1])*125.62f, (3.3f*ADC_read(adc2)+adc_corr[2])/0.207f, 3.3f*ADC_read(adc3)+adc_corr[3]); } printf("\n"); wait(0.005); } }