Embedded coursework 2.
Dependencies: IndiCorp mbed-rtos mbed
main.cpp
- Committer:
- trod
- Date:
- 2018-03-23
- Revision:
- 0:f3f1e48b3e4b
File content as of revision 0:f3f1e48b3e4b:
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~INCLUDES~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include "mbed.h" #include "Crypto.h" // Library used for Bitcoin mining. #include "rtos.h" // Real time operating system library for threads etc. //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~DEFINITIONS~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //~~~~~~~~~~~~~~Photointerrupter pins~~~~~~~~~~~~~~ #define I1pin D2 #define I2pin D11 #define I3pin D12 ////~~~~~~~~~~Incremental encoder pins//~~~~~~~~~~~ #define CHA D7 #define CHB D8 //~~Motor Drive output pins~/Mask in output byte~~~ #define L1Lpin D4 //0x01 #define L1Hpin D5 //0x02 #define L2Lpin D3 //0x04 #define L2Hpin D6 //0x08 #define L3Lpin D9 //0x10 #define L3Hpin D10 //0x20 //~~~~~~~~Maximum command length accepted~~~~~~~~~~~ #define MAXCMDLENGTH 18 //~~~~~~~~Maximum PWM allowed due to 50% restriction #define MAXPWM 1000 //~~~~~~~Enumeration of message identifiers~~~~~~~~~ enum MsgCode {Msg_motorState, Msg_hashRate, Msg_nonceMatch, Msg_keyAdded, Msg_velocityOut, Msg_velocityIn, Msg_positionIn, Msg_positionOut, Msg_rotations, Msg_torque, Msg_error}; //~~~~~~~New data type to carry the messages~~~~~~~~ typedef struct { MsgCode code; uint32_t data; } message_t; //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Global Variables~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //Mapping from sequential drive states to motor phase outputs /* State L1 L2 L3 0 H - L 1 - H L 2 L H - 3 L - H 4 - L H 5 H L - 6 - - - 7 - - - */ //~~~~~~~~~~~Drive state to output table~~~~~~~~~~~~ const int8_t driveTable[] = {0x12,0x18,0x09,0x21,0x24,0x06,0x00,0x00}; //Mapping from interrupter inputs to sequential rotor states. 0x00 and 0x07 are not valid. const int8_t stateMap[] = {0x07,0x05,0x03,0x04,0x01,0x00,0x02,0x07}; //Alternative if phase order of input or drive is reversed. //const int8_t stateMap[] = {0x07,0x01,0x03,0x02,0x05,0x00,0x04,0x07}; ////~~~~~~~~~Phase lead to make motor spin~~~~~~~~~ int8_t lead = 2; //2 for forwards, -2 for backwards //~~~~~~~~~~~~~~~~~~Rotor states~~~~~~~~~~~~~~~~~~~ int8_t orState = 0; // Rotor offset at motor state 0 volatile int8_t intStateOld = 0; // Motor old state. Type is volatile since // its value may change in ISR //~~~~~~~~~~~~~~~~~~~Status LED~~~~~~~~~~~~~~~~~~~~ DigitalOut led1(LED1); //~~~~~~~~~~~~~Photointerrupter inputs~~~~~~~~~~~~~ InterruptIn I1(I1pin); InterruptIn I2(I2pin); InterruptIn I3(I3pin); //~~~~~~~~~~~~~~Motor Drive outputs~~~~~~~~~~~~~~~~ PwmOut L1L(L1Lpin); DigitalOut L1H(L1Hpin); PwmOut L2L(L2Lpin); DigitalOut L2H(L2Hpin); PwmOut L3L(L3Lpin); DigitalOut L3H(L3Hpin); //~Dats structure to pass information between threads~ Mail<message_t,16> outMessages; //~~~~~~~~~~~~~~~~~~~~Queue~~~~~~~~~~~~~~~~~~~~~~~~ Queue<void, 8> inCharQ; //~~~~~~~~~~~~Serial command buffer~~~~~~~~~~~~~~~ char newCmd[MAXCMDLENGTH]; volatile uint8_t cmdIndx = 0; //~~~~~~~~~~Key to be passed for mining~~~~~~~~~~~ volatile uint64_t newKey; // Key Mutex newKey_mutex; // Restrict access to prevent deadlock. //~~~~~~~~~~~~~~Initial conditions~~~~~~~~~~~~~~~~ volatile uint32_t motorPower = 300; // motor toque volatile float targetVel = 45.0; volatile float targetRot = 459.0; //~~~~~~~~~~~Motor position variable~~~~~~~~~~~~~~ volatile int32_t motorPos; // Motor position updated by interrupt. //~~~~~~~~~~Serial port connection~~~~~~~~~~~~~~~~ RawSerial pc(SERIAL_TX, SERIAL_RX); //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Threads~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Thread commOutT(osPriorityAboveNormal,1024); // Output to serial port. Thread commInT(osPriorityAboveNormal,1024); // Input from serial port. Thread motorCtrlT(osPriorityNormal,1024); // Motor control thread. //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Function declarations~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ void motorOut(int8_t driveState, uint32_t pw); inline int8_t readRotorState(); int8_t motorHome(); void motorISR(); void cmdParser(); void commOutFn(); void putMessage(MsgCode code, uint32_t data); void serialISR(); void commInFn(); void motorCtrlFn(); void motorCtrlTick(); //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Main~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ int main() { //~~~~~~~~~~~~~Initial serial prints~~~~~~~~~~~~~ pc.printf("\n\r\n\r Hello \n\r"); pc.printf("\n\r\n\rGroup: IndiCorp \n\r"); pc.printf("Initial hardcoded conditions:\n\r"); pc.printf("\tVelocity:\t%f\n\r", targetVel); pc.printf("\tRotation:\t%f\n\r", targetRot); //~~~~~~~~~~~~~~~Start all threads~~~~~~~~~~~~~~~ commOutT.start(commOutFn); commInT.start(commInFn); motorCtrlT.start(motorCtrlFn); //~~~~~~~~~~~~~~Attach ISR to serial~~~~~~~~~~~~ pc.attach(&serialISR); //~~~~~~~~Attach ISR to photointerrupters~~~~~~~ I1.rise(&motorISR); I1.fall(&motorISR); I2.rise(&motorISR); I2.fall(&motorISR); I3.rise(&motorISR); I3.fall(&motorISR); //~~~~~~~~~Declare Bitcoin Variables~~~~~~~~~~~ SHA256 sha256Inst; uint8_t sequence[] = {\ 0x45,0x6D,0x62,0x65,0x64,0x64,0x65,0x64,\ 0x20,0x53,0x79,0x73,0x74,0x65,0x6D,0x73,\ 0x20,0x61,0x72,0x65,0x20,0x66,0x75,0x6E,\ 0x20,0x61,0x6E,0x64,0x20,0x64,0x6F,0x20,\ 0x61,0x77,0x65,0x73,0x6F,0x6D,0x65,0x20,\ 0x74,0x68,0x69,0x6E,0x67,0x73,0x21,0x20,\ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,\ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; uint64_t* key = (uint64_t*)((int)sequence + 48); uint64_t* nonce = (uint64_t*)((int)sequence + 56); uint8_t hash[32]; uint32_t sequenceLength = 64; uint32_t hashCounter = 0; Timer bitcoinTimer; //Set PWM period to max 2000 due to hardware limitations L1L.period_us(2000); L2L.period_us(2000); L3L.period_us(2000); /* Run the motor synchronisation: orState is subtracted from future rotor state inputs to align rotor and motor states */ orState = motorHome(); pc.printf("Rotor origin: %x\n\r", orState); //Print state for debugging purposes. //~~~~~~Give the motor a kick to begin~~~~~~~~ motorISR(); //~~~~~~~~~~~~~~~~Mining loop~~~~~~~~~~~~~~~~~ bitcoinTimer.start(); // start timer while (1) { newKey_mutex.lock(); (*key) = newKey; newKey_mutex.unlock(); sha256Inst.computeHash(hash, sequence, sequenceLength); hashCounter++; if ((hash[0]==0) && (hash[1]==0)){ putMessage(Msg_nonceMatch, *nonce); // matching nonce } (*nonce)++; if (bitcoinTimer.read() >= 1){ putMessage(Msg_hashRate, hashCounter); hashCounter=0; bitcoinTimer.reset(); } } } //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Functions Definitions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //~~~~~~~~~~~~Set a given drive state~~~~~~~~~~~~ void motorOut(int8_t driveState, uint32_t pw){ //Lookup the output byte from the drive state. int8_t driveOut = driveTable[driveState & 0x07]; //Turn off first if (~driveOut & 0x01) L1L.pulsewidth_us(0); if (~driveOut & 0x02) L1H = 1; if (~driveOut & 0x04) L2L.pulsewidth_us(0); if (~driveOut & 0x08) L2H = 1; if (~driveOut & 0x10) L3L.pulsewidth_us(0); if (~driveOut & 0x20) L3H = 1; //Then turn on if (driveOut & 0x01) L1L.pulsewidth_us(pw); if (driveOut & 0x02) L1H = 0; if (driveOut & 0x04) L2L.pulsewidth_us(pw); if (driveOut & 0x08) L2H = 0; if (driveOut & 0x10) L3L.pulsewidth_us(pw); if (driveOut & 0x20) L3H = 0; } //~Convert photointerrupter inputs to a rotor state~ inline int8_t readRotorState(){ return stateMap[I1 + 2*I2 + 4*I3]; } //~~~~~~Basic motor synchronisation routine~~~~~~ int8_t motorHome() { //Put the motor in drive state 0 and wait for it to stabilise motorOut(0, MAXPWM); // set to max PWM wait(2.0); //Get the rotor state return readRotorState(); } //~~~~~~~~~Motor ISR (photointerrupters)~~~~~~~~~ void motorISR() { static int8_t oldRotorState; int8_t rotorState = readRotorState(); motorOut((rotorState-orState+lead+6)%6,motorPower); // update motorPosition and oldRotorState if (rotorState - oldRotorState == 5) motorPos--; else if (rotorState - oldRotorState == -5) motorPos++; else motorPos += (rotorState - oldRotorState); oldRotorState = rotorState; } //~~~~~Decode messages to print on serial port~~~~~ void commOutFn() { while(1) { osEvent newEvent = outMessages.get(); message_t *pMessage = (message_t*)newEvent.value.p; //Case switch to choose serial output based on incoming message switch(pMessage->code) { case Msg_motorState: pc.printf("The motor is currently in state %x\n\r", pMessage->data); break; case Msg_hashRate: pc.printf("Mining at a rate of %.2f Hash/s\n\r", (int32_t)pMessage->data); break; case Msg_nonceMatch: pc.printf("Nonce found: %x\n\r", pMessage->data); break; case Msg_keyAdded: pc.printf("New key added:\t0x%016x\n\r", pMessage->data); break; case Msg_torque: pc.printf("Motor torque set to:\t%d\n\r", pMessage->data); break; case Msg_velocityIn: pc.printf("Target velocity set to:\t%.2f\n\r", targetVel); break; case Msg_velocityOut: pc.printf("Current Velocity:\t%.2f\n\r", \ (float)((int32_t)pMessage->data / 6)); break; case Msg_positionIn: pc.printf("Target rotation set to:\t%.2f\n\r", \ (float)((int32_t)pMessage->data / 6)); break; case Msg_positionOut: pc.printf("Current position:\t%.2f\n\r", \ (float)((int32_t)pMessage->data / 6)); break; case Msg_error: pc.printf("Debugging position:%x\n\r", pMessage->data); break; default: pc.printf("Unknown Error. Data: %x\n\r", pMessage->data); break; } outMessages.free(pMessage); } } //~~~~~~~~~Put message in Mail queue~~~~~~~~~~~ void putMessage(MsgCode code, uint32_t data){ message_t *pMessage = outMessages.alloc(); pMessage->code = code; pMessage->data = data; outMessages.put(pMessage); } //~~~~Receive & decode serial input command~~~~~ void commInFn() { while (1) { osEvent newEvent = inCharQ.get(); uint8_t newChar = *((uint8_t*)(&newEvent.value.p)); pc.putc(newChar); if(cmdIndx >= MAXCMDLENGTH){ //Make sure there is no overflow in comand. cmdIndx = 0; putMessage(Msg_error, 1); } else{ if(newChar != '\r'){ //While the command is not over, newCmd[cmdIndx] = newChar; //save input character and cmdIndx++; //advance index } else{ newCmd[cmdIndx] = '\0'; //When the command is finally over, cmdIndx = 0; //reset index and cmdParser(); //parse the command for decoding. } } } } //~~~~~~~~~~~~~Decode the command~~~~~~~~~~~ void cmdParser(){ switch(newCmd[0]) { case 'K': newKey_mutex.lock(); //Ensure there is no deadlock sscanf(newCmd, "K%x", &newKey); //Find desired the Key code putMessage(Msg_keyAdded, newKey); //Print it out newKey_mutex.unlock(); break; case 'V': sscanf(newCmd, "V%f", &targetVel); //Find desired the target velocity putMessage(Msg_velocityIn, targetVel); //Print it out break; case 'R': sscanf(newCmd, "R%f", &targetRot); //Find desired target rotation putMessage(Msg_positionIn, targetRot); //Print it out break; case 'T': sscanf(newCmd, "T%d", &motorPower); //Find desired target torque putMessage(Msg_torque, motorPower); //Print it out break; default: break; } } //~~~~~~~~~~~~~Serial ISR~~~~~~~~~~~~ void serialISR() { uint8_t newChar = pc.getc(); inCharQ.put((void*)newChar); } //~~~~~~ISR triggered by Ticker~~~~~~ void motorCtrlTick(){ motorCtrlT.signal_set(0x1); //Set signal to motor control thread which carries out calculations to avoid CPU blocking } //~~~~~~~~~~~~~Motor control function with proportional controller~~~~~~~~~~~ void motorCtrlFn() { //~~~~~~~~~~~~~Variables~~~~~~~~~~~~~~~~ Ticker motorCtrlTicker; //Ticker to ba attached to callback function int32_t velocity; //Variable for local velocity calculation int32_t locMotorPos; //Local copy of motor position static int32_t oldMotorPos = 0; //Old motor position used for calculations static uint8_t motorCtrlCounter = 0; //Counter to be reset every 10 iterations to get velocity calculation in seconds int32_t torque; //Local variable to set motor torque float sError; //Velocity error between target and reality float rError; //Rotation error between target and reality static float rErrorOld; //Old rotation error used for calculation //~~~Controller constants~~~~ int32_t Kp1=22; //Proportional controller constants int32_t Kp2=22; //Calculated by trial and error to give optimal accuracy float Kd=15.5; //Attach ticker to callback function that will run every 100 ms motorCtrlTicker.attach_us(&motorCtrlTick,100000); while(1) { motorCtrlT.signal_wait(0x1); // Wait for thread signal. //Initial velocity calculation and report locMotorPos = motorPos; //Read global variable motorPos which is updated by interrupt and store it in local variable velocity = (locMotorPos - oldMotorPos) * 10; //Proceed with calculation oldMotorPos = locMotorPos; //Update old motor position motorCtrlCounter++; //Advance counter if (motorCtrlCounter >= 10) { //Every 10th iteration motorCtrlCounter = 0; //Reset counter putMessage(Msg_velocityOut, velocity); //Report the current velocity putMessage(Msg_positionOut, locMotorPos); //Report the current position } //~~~~~Speed controller~~~~~~ sError = (targetVel * 6) - abs(velocity); //Read global variable targetVel updated by interrupt and calculate error between target and reality int32_t Ys; //Initialise controller output Ys if (sError == -abs(velocity)) { //Check if user entered V0, Ys = MAXPWM; //and set the output to maximum as specified } else { Ys = (int)(Kp1 * sError); //If the user didn't enter V0 implement controller transfer function: Ys = Kp * (s -|v|) where, } //Ys = controller output, Kp = prop controller constant, s = target velocity and v is the measured velocity //~~~~~Rotation control~~~~~~ rError = targetRot - (locMotorPos/6); //Read global variable targetRot updated by interrupt and calculate the rotation error. int32_t Yr; //Initialise controller output Yr Yr = Kp2*rError + Kd*(rError - rErrorOld); //Implement controller transfer function Ys= Kp*Er + Kd* (dEr/dt) rErrorOld = rError; //Update rotation error if(rError < 0){ //Use the sign of the error to set controller wrt direction of rotation Ys = -Ys; } if((velocity>=0 && Ys<Yr) || (velocity<0 && Ys>Yr)){ //Choose Ys or Yr based on distance from target value so that it takes torque = Ys; //appropriate steps in the right direction to reach target value } else{ torque = Yr; } if(torque < 0){ //Variable torque cannot be negative since it sets the PWM torque = -torque; //Hence we make the value positive, lead = -2; //and instead set the direction to the opposite one } else{ lead = 2; } if(torque > MAXPWM){ //In case the calculated PWM is higher than our maximum 50% allowance, torque = MAXPWM; //Set it to our max. } motorPower = torque; //Lastly, update global variable motorPower which is updated by interrupt } }