Embedded coursework 2.
Dependencies: IndiCorp mbed-rtos mbed
Diff: main.cpp
- Revision:
- 0:f3f1e48b3e4b
diff -r 000000000000 -r f3f1e48b3e4b main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Fri Mar 23 20:05:08 2018 +0000 @@ -0,0 +1,512 @@ +//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~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 + } +}