misc avr fixes
[ros_wild_thumper.git] / avr / motor_ctrl / main.c
index 9c6413c..ec9965f 100644 (file)
@@ -5,6 +5,9 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <avr/sleep.h>
+#include <util/twi.h>
+#include <avr/eeprom.h>
+#include <avr/wdt.h>
 #include "uart.h"
 
 /*
  * 0x02 Motor 1 PWM LSB
  * 0x03 Motor 2 PWM MSB
  * 0x04 Motor 2 PWM LSB
+ * 0x05 Motor 3 PWM MSB
+ * 0x06 Motor 3 PWM LSB
+ * 0x07 Motor 4 PWM MSB
+ * 0x08 Motor 4 PWM LSB
  * free
  * 0x10 Hall 1 MSB
  * 0x11 Hall 1 LSB
  * 0x21 Motor 1 speed wish LSB
  * 0x22 Motor 2 speed wish MSB
  * 0x23 Motor 2 speed wish LSB
+ * 0x24 Motor 3 speed wish MSB
+ * 0x25 Motor 3 speed wish LSB
+ * 0x26 Motor 4 speed wish MSB
+ * 0x27 Motor 4 speed wish LSB
  * 0x28 Left speed wish (m/s) MSB
  * 0x29 Left speed wish (m/s)
  * 0x2A Left speed wish (m/s)
  * 0x31 Motor 1 speed LSB
  * 0x32 Motor 2 speed MSB
  * 0x33 Motor 2 speed LSB
+ * 0x34 Motor 3 speed MSB
+ * 0x35 Motor 3 speed LSB
+ * 0x36 Motor 4 speed MSB
+ * 0x37 Motor 4 speed LSB
  * 0x38 Speed (m/s) MSB
  * 0x39 Speed (m/s)
  * 0x3A Speed (m/s)
  * free
  * 0x90 Motor 1 switch
  * 0x91 Motor 2 switch
+ * 0x92 Motor 3 switch
+ * 0x93 Motor 4 switch
+ * 0x94 Front Handicap
+ * 0x95 Aft Handicap
  * free
  * 0xA0 Reset reason
  * 0xA1 Error status
  */
 
 
-#define TWI_ACK                TWCR = (1<<TWEA) | (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
-#define TWI_RESET      TWCR &= ~((1 << TWSTO) | (1 << TWEN)); TWI_ACK
-#define TWI_NAK                TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
-
-#define KP 0.045
-#define KI 2.298
-#define KD 0.0004
+#define KP 0.062
+#define KI 0.12
+#define KD 0.0
 #define PID_T 0.01
-// wheel diameter=12cm, encoder=48cpr, gear ratio=1:34, real wheel diameter: 0.12454m
-#define STEP_PER_M_AVG 4171.4
-#define STEP_PER_M_LEFT (STEP_PER_M_AVG)
-#define STEP_PER_M_RIGHT (STEP_PER_M_AVG)
-#define WHEEL_DIST 0.36923 // Real: 0.252
+// wheel diameter=12cm, encoder=48cpr, gear ratio=1:47
+// STEP_PER_M = 48*47/(d*pi)
+// Left real diameter: 0.12808, Right real diameter: 0.121
+#define STEP_PER_M 5573.0
+#define STEP_PER_M_LEFT (STEP_PER_M)
+#define STEP_PER_M_RIGHT (STEP_PER_M)
+#define WHEEL_DIST 0.39912 // Measured: 0.252
+#define PWM_BREAK INT16_MIN
+#define STALL_LIMIT 140000
+
+#define TWI_ACK   TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWEN) | (1<<TWIE)
+#define TWI_NAK   TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
+#define TWI_RESET TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWSTO) | (1<<TWEN) | (1<<TWIE);
+#define ENABLE_PWM_MOTOR1  TCCR1A |=  (1 << COM1A1)
+#define ENABLE_PWM_MOTOR2  TCCR1A |=  (1 << COM1B1)
+#define ENABLE_PWM_MOTOR3  TCCR2  |=  (1 << COM21);
+#define ENABLE_PWM_MOTOR4  TCCR0  |=  (1 << COM01);
+#define DISABLE_PWM_MOTOR1 TCCR1A &= ~(1 << COM1A1)
+#define DISABLE_PWM_MOTOR2 TCCR1A &= ~(1 << COM1B1)
+#define DISABLE_PWM_MOTOR3 TCCR2  &= ~(1 << COM21);
+#define DISABLE_PWM_MOTOR4 TCCR0  &= ~(1 << COM01);
+
 
 enum mode {
        MOTOR_MANUAL,
@@ -115,29 +147,41 @@ static volatile uint8_t ireg=0;
 static volatile uint8_t bootloader=0;
 static volatile int16_t motor1=0; // -255..+255
 static volatile int16_t motor2=0;
+static volatile int16_t motor3=0;
+static volatile int16_t motor4=0;
 static volatile int16_t pos1=0; // step
 static volatile int16_t pos2=0;
 static volatile int16_t pos3=0;
 static volatile int16_t pos4=0;
 static volatile enum mode motor1_mode=MOTOR_MANUAL;
 static volatile enum mode motor2_mode=MOTOR_MANUAL;
-static volatile uint8_t motor1_switch=0;
+static volatile enum mode motor3_mode=MOTOR_MANUAL;
+static volatile enum mode motor4_mode=MOTOR_MANUAL;
+static volatile uint8_t motor1_switch=1;
 static volatile uint8_t motor2_switch=1;
+static volatile uint8_t motor3_switch=0;
+static volatile uint8_t motor4_switch=0;
 static volatile int16_t speed1_wish=0; // step/s
 static volatile int16_t speed2_wish=0;
+static volatile int16_t speed3_wish=0;
+static volatile int16_t speed4_wish=0;
+static volatile int16_t speed1_wish_old=0;
+static volatile int16_t speed2_wish_old=0;
+static volatile int16_t speed3_wish_old=0;
+static volatile int16_t speed4_wish_old=0;
 static volatile uint8_t run_update=0;
 static volatile int16_t speed1=0; // step/s
 static volatile int16_t speed2=0;
 static volatile int16_t speed3=0;
 static volatile int16_t speed4=0;
-static volatile int16_t speed_l=0;
-static volatile int16_t speed_r=0;
 static volatile ufloat_t pos_x={0.0};
 static volatile ufloat_t pos_y={0.0};
 static volatile ufloat_t angle={0.0};
 static volatile float cur_speed_lin=0;
 static volatile float cur_speed_rot=0;
 static volatile uint8_t count_test=0;
+static volatile uint8_t front_handicap=0;
+static volatile uint8_t aft_handicap=0;
 static volatile uint8_t error_state=0;
 
 ISR(TWI_vect)
@@ -147,13 +191,13 @@ ISR(TWI_vect)
        static ufloat_t tmp_speed;
        static ufloat_t tmp_angle;
 
-       switch (TWSR & 0xF8)
-       {  
-               case 0x60: // start write
+       switch(TW_STATUS)
+       {
+               case TW_SR_SLA_ACK: // start write
                        TWI_ACK;
                        ireg = 0;
                        break;
-               case 0x80: // write
+               case TW_SR_DATA_ACK: // write
                        switch(ireg) {
                                case 0x00: // register select
                                        ireg = TWDR;
@@ -178,6 +222,24 @@ ISR(TWI_vect)
                                        motor2_mode = MOTOR_MANUAL;
                                        TWI_ACK;
                                        break;
+                               case 0x05: // Motor 3 MSB
+                                       tmp = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x06: // Motor 3 LSB
+                                       motor3 = tmp<<8 | TWDR;
+                                       motor3_mode = MOTOR_MANUAL;
+                                       TWI_ACK;
+                                       break;
+                               case 0x07: // Motor 4 MSB
+                                       tmp = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x08: // Motor 4 LSB
+                                       motor4 = tmp<<8 | TWDR;
+                                       motor4_mode = MOTOR_MANUAL;
+                                       TWI_ACK;
+                                       break;
                                case 0x20: // Motor 1 speed wish MSB
                                        tmp = TWDR;
                                        TWI_ACK;
@@ -196,6 +258,24 @@ ISR(TWI_vect)
                                        motor2_mode = MOTOR_PID;
                                        TWI_ACK;
                                        break;
+                               case 0x24: // Motor 3 speed wish MSB
+                                       tmp = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x25: // Motor 3 speed wish LSB
+                                       speed3_wish = tmp<<8 | TWDR;
+                                       motor3_mode = MOTOR_PID;
+                                       TWI_ACK;
+                                       break;
+                               case 0x26: // Motor 4 speed wish MSB
+                                       tmp = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x27: // Motor 4 speed wish LSB
+                                       speed4_wish = tmp<<8 | TWDR;
+                                       motor4_mode = MOTOR_PID;
+                                       TWI_ACK;
+                                       break;
                                case 0x28: // Left speed wish MSB
                                        tmp_speed.i = TWDR;
                                        TWI_ACK;
@@ -279,24 +359,66 @@ ISR(TWI_vect)
                                        motor2_switch = TWDR;
                                        TWI_ACK;
                                        break;
+                               case 0x92: // Motor 3 switch
+                                       motor3_switch = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x93: // Motor 4 switch
+                                       motor4_switch = TWDR;
+                                       TWI_ACK;
+                                       break;
+                               case 0x94: // Front Handicap
+                                       front_handicap = TWDR;
+                                       cmd_vel.bUpdate = 1;
+                                       TWI_ACK;
+                                       break;
+                               case 0x95: // Aft Handicap
+                                       aft_handicap = TWDR;
+                                       cmd_vel.bUpdate = 1;
+                                       TWI_ACK;
+                                       break;
                                case 0xff: // bootloader
                                        bootloader = TWDR;
                                default:
                                        TWI_NAK;
                        }
-                       ireg++;
+                       if (ireg < 0xff) ireg++;
                        break;
-               case 0xA8: // start read
-               case 0xB8: // read
+               case TW_ST_SLA_ACK: // start read
+               case TW_ST_DATA_ACK: // read
                        switch(ireg) {
                                case 0x02: // Motor 1 PWM
                                        TWDR = OCR1A;
                                        TWI_ACK;
                                        break;
+                               case 0x03: // Dummy to allow continous read
+                                       TWDR = 0;
+                                       TWI_ACK;
+                                       break;
                                case 0x04: // Motor 2 PWM
                                        TWDR = OCR1B;
                                        TWI_ACK;
                                        break;
+                               case 0x05: // Dummy to allow continous read
+                                       TWDR = 0;
+                                       TWI_ACK;
+                                       break;
+                               case 0x06: // Motor 3 PWM
+                                       TWDR = OCR2;
+                                       TWI_ACK;
+                                       break;
+                               case 0x07: // Dummy to allow continous read
+                                       TWDR = 0;
+                                       TWI_ACK;
+                                       break;
+                               case 0x08: // Motor 4 PWM
+                                       TWDR = OCR0;
+                                       TWI_ACK;
+                                       break;
+                               case 0x09: // Dummy to allow continous read
+                                       TWDR = 0;
+                                       TWI_ACK;
+                                       break;
                                case 0x10: // Hall 1 MSB
                                        tmp16 = pos1;
                                        TWDR = tmp16>>8;
@@ -349,6 +471,22 @@ ISR(TWI_vect)
                                        TWDR = speed2_wish;
                                        TWI_ACK;
                                        break;
+                               case 0x24: // Motor 3 speed wish MSB
+                                       TWDR = speed3_wish>>8;
+                                       TWI_ACK;
+                                       break;
+                               case 0x25: // Motor 3 speed wish LSB
+                                       TWDR = speed3_wish;
+                                       TWI_ACK;
+                                       break;
+                               case 0x26: // Motor 4 speed wish MSB
+                                       TWDR = speed4_wish>>8;
+                                       TWI_ACK;
+                                       break;
+                               case 0x27: // Motor 4 speed wish LSB
+                                       TWDR = speed4_wish;
+                                       TWI_ACK;
+                                       break;
                                case 0x30: // Motor 1 speed MSB
                                        TWDR = speed1>>8;
                                        TWI_ACK;
@@ -468,7 +606,7 @@ ISR(TWI_vect)
                                        MCUCSR = 0x0;
                                        TWI_ACK;
                                        break;
-                               case 0xA1: // TLE Error status
+                               case 0xA1: // Error status
                                        TWDR = error_state;
                                        TWI_ACK;
                                        break;
@@ -481,6 +619,9 @@ ISR(TWI_vect)
                        }
                        ireg++;
                        break;
+               case TW_SR_STOP:
+                       TWI_ACK;
+                       break;
                default:
                        TWI_RESET;
        }
@@ -500,8 +641,8 @@ static void update_hall1(void) {
        diff = oldstatus - new;                         // difference last - new
        if (diff & 0x1) {                               // bit 0 = value (1)
                oldstatus = new;                                        // store new as next last
-               if (motor1_switch) pos1 -= (diff & 2) - 1;              // bit 1 = direction (+/-)
-               else pos1 += (diff & 2) - 1;
+               if (motor1_switch) pos1 += (diff & 2) - 1;              // bit 1 = direction (+/-)
+               else pos1 -= (diff & 2) - 1;
        }
 }
 
@@ -519,7 +660,7 @@ static void update_hall2(void) {
        diff = oldstatus - new;                         // difference last - new
        if (diff & 0x1) {                               // bit 0 = value (1)
                oldstatus = new;                                        // store new as next last
-               if (motor1_switch) pos2 -= (diff & 2) - 1;              // bit 1 = direction (+/-)
+               if (motor2_switch) pos2 -= (diff & 2) - 1;              // bit 1 = direction (+/-)
                else pos2 += (diff & 2) - 1;
        }
 }
@@ -538,8 +679,8 @@ static void update_hall3(void) {
        diff = oldstatus - new;                         // difference last - new
        if (diff & 0x1) {                               // bit 0 = value (1)
                oldstatus = new;                                        // store new as next last
-               if (motor2_switch) pos3 += (diff & 2) - 1;              // bit 1 = direction (+/-)
-               else pos3 -= (diff & 2) - 1;
+               if (motor3_switch) pos3 -= (diff & 2) - 1;              // bit 1 = direction (+/-)
+               else pos3 += (diff & 2) - 1;
        }
 }
 
@@ -557,8 +698,8 @@ static void update_hall4(void) {
        diff = oldstatus - new;                         // difference last - new
        if (diff & 0x1) {                               // bit 0 = value (1)
                oldstatus = new;                                        // store new as next last
-               if (motor2_switch) pos4 -= (diff & 2) - 1;              // bit 1 = direction (+/-)
-               else pos4 += (diff & 2) - 1;
+               if (motor4_switch) pos4 += (diff & 2) - 1;              // bit 1 = direction (+/-)
+               else pos4 -= (diff & 2) - 1;
        }
 }
 
@@ -566,36 +707,34 @@ static void update_hall4(void) {
 static void update_motor(void) {
        static int16_t m1_old=SHRT_MIN;
        static int16_t m2_old=SHRT_MIN;
+       static int16_t m3_old=SHRT_MIN;
+       static int16_t m4_old=SHRT_MIN;
 
-       error_state = ~(PINB & 0x03);
-
-       if (motor1_mode == MOTOR_PID && bit_is_set(error_state, 0)) {
-               // if error and running: stop
-               if (m1_old != 0) motor1 = 0;
-               // if we start motor in error state: start with full power
-               else if (motor1 > 0) motor1 = 255;
-               else if (motor1 < 0) motor1 = -255;
-       }
-       if (motor2_mode == MOTOR_PID && bit_is_set(error_state, 1)) {
-               // if error and running: stop
-               if (m2_old != 0) motor2 = 0;
-               // if we start motor in error state: start with full power
-               else if (motor2 > 0) motor2 = 255;
-               else if (motor2 < 0) motor2 = -255;
-       }
+       error_state &= 0xf0; // clear lower bits
+       error_state |= ~((PIND & 0x40)>>3 | (PINB & 0x07)) & 0xf;
 
        if (m1_old != motor1) { // update only when changed
                if (motor1 == 0) {
                        // stop
                        PORTC &= ~(1 << 3) & ~(1 << 2);
+                       DISABLE_PWM_MOTOR1;
+               } else if (motor1 == PWM_BREAK) {
+                       PORTC |= (1 << 3) | (1 << 2);
+                       ENABLE_PWM_MOTOR1;
                } else if ((!motor1_switch && motor1 > 0) || (motor1_switch && motor1 < 0)) {
                        // forward
-                       PORTC |=  (1 << 2);
-                       PORTC &= ~(1 << 3);
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 3);
+                       tmp |=  (1 << 2);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR1;
                } else { // motor1 < 0
                        // backward
-                       PORTC &= ~(1 << 2);
-                       PORTC |=  (1 << 3);
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 2);
+                       tmp |=  (1 << 3);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR1;
                }
 
                m1_old = motor1;
@@ -606,19 +745,85 @@ static void update_motor(void) {
                if (motor2 == 0) {
                        // stop
                        PORTC &= ~(1 << 5) & ~(1 << 4);
+                       DISABLE_PWM_MOTOR2;
+               } else if (motor2 == PWM_BREAK) {
+                       PORTC |= (1 << 5) | (1 << 4);
+                       ENABLE_PWM_MOTOR2;
                } else if ((!motor2_switch && motor2 > 0) || (motor2_switch && motor2 < 0)) {
                        // forward
-                       PORTC |=  (1 << 4);
-                       PORTC &= ~(1 << 5);
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 5);
+                       tmp |=  (1 << 4);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR2;
                } else { // motor2 < 0
                        // backward
-                       PORTC &= ~(1 << 4);
-                       PORTC |=  (1 << 5);
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 4);
+                       tmp |=  (1 << 5);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR2;
                }
 
                m2_old = motor2;
                OCR1B = abs(motor2);
        }
+
+       if (m3_old != motor3) { // update only when changed
+               if (motor3 == 0) {
+                       // stop
+                       PORTC &= ~(1 << 7) & ~(1 << 6);
+                       DISABLE_PWM_MOTOR3;
+               } else if (motor3 == PWM_BREAK) {
+                       PORTC |= (1 << 7) | (1 << 6);
+                       ENABLE_PWM_MOTOR3;
+               } else if ((!motor3_switch && motor3 > 0) || (motor3_switch && motor3 < 0)) {
+                       // forward
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 7);
+                       tmp |=  (1 << 6);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR3;
+               } else { // motor3 < 0
+                       // backward
+                       uint8_t tmp=PORTC;
+                       tmp &= ~(1 << 6);
+                       tmp |=  (1 << 7);
+                       PORTC = tmp;
+                       ENABLE_PWM_MOTOR3;
+               }
+
+               m3_old = motor3;
+               OCR2 = abs(motor3);
+       }
+
+       if (m4_old != motor4) { // update only when changed
+               if (motor4 == 0) {
+                       // stop
+                       PORTD &= ~(1 << 3) & ~(1 << 2);
+                       DISABLE_PWM_MOTOR4;
+               } else if (motor4 == PWM_BREAK) {
+                       PORTD |= (1 << 3) | (1 << 2);
+                       ENABLE_PWM_MOTOR4;
+               } else if ((!motor4_switch && motor4 > 0) || (motor4_switch && motor4 < 0)) {
+                       // forward
+                       uint8_t tmp=PORTD;
+                       tmp &= ~(1 << 3);
+                       tmp |=  (1 << 2);
+                       PORTD = tmp;
+                       ENABLE_PWM_MOTOR4;
+               } else { // motor4 < 0
+                       // backward
+                       uint8_t tmp=PORTD;
+                       tmp &= ~(1 << 2);
+                       tmp |=  (1 << 3);
+                       PORTD = tmp;
+                       ENABLE_PWM_MOTOR4;
+               }
+
+               m4_old = motor4;
+               OCR0 = abs(motor4);
+       }
 }
 
 
@@ -667,10 +872,8 @@ static void update_pos(void) {
        pos_x_new = pos_x.f + cos(angle_new)*translation;
        pos_y_new = pos_y.f + sin(angle_new)*translation;
 
-       speed_l = (new_speed1+new_speed2)/2;
-       speed_r = (new_speed3+new_speed4)/2;
-       tmp_speed_lin = (speed_l + speed_r)/(2.0*STEP_PER_M_AVG);
-       tmp_speed_rot = (speed_r - speed_l)/(M_PI*WHEEL_DIST*STEP_PER_M_AVG);
+       tmp_speed_lin = translation/PID_T;
+       tmp_speed_rot = angle_diff/PID_T;
 
        // copy from tmp
        cli();
@@ -695,39 +898,131 @@ static void update_pos(void) {
 static void update_pid(void) {
        static int16_t eold1=0;
        static int16_t eold2=0;
+       static int16_t eold3=0;
+       static int16_t eold4=0;
        static int32_t esum1=0;
        static int32_t esum2=0;
+       static int32_t esum3=0;
+       static int32_t esum4=0;
+
+       // protect motors from damage if stalling
+       if (labs(esum1) > STALL_LIMIT && speed1 == 0) {
+               motor1 = 0;
+               motor1_mode = MOTOR_MANUAL;
+               error_state |= (1<<4);
+               esum1 = 0;
+       }       
+       if (labs(esum2) > STALL_LIMIT && speed2 == 0) {
+               motor2 = 0;
+               motor2_mode = MOTOR_MANUAL;
+               error_state |= (1<<5);
+               esum2 = 0;
+       }       
+       if (labs(esum3) > STALL_LIMIT && speed3 == 0) {
+               motor3 = 0;
+               motor3_mode = MOTOR_MANUAL;
+               error_state |= (1<<6);
+               esum3 = 0;
+       }       
+       if (labs(esum4) > STALL_LIMIT && speed4 == 0) {
+               motor4 = 0;
+               motor4_mode = MOTOR_MANUAL;
+               error_state |= (1<<7);
+               esum4 = 0;
+       }       
 
        if (motor1_mode == MOTOR_PID) {
-               if (speed1_wish == 0) {
+               if (speed1_wish != speed1_wish_old) {
+                       if (abs(speed1_wish - speed1_wish_old) > 500) esum1 = 0;
+                       speed1_wish_old = speed1_wish;
+               }
+
+               uint8_t dir_change = (speed1_wish > 0 && speed1 < 0) || (speed1_wish < 0 && speed1 > 0); // Prevent dangerous immediate engine reverse
+               if (speed1_wish == 0 || dir_change) {
                        motor1 = 0;
                        eold1 = 0;
-                       esum1 = 0;
+                       error_state &= ~(1<<4);
                } else {
-                       int16_t e = speed1_wish - speed_l;
+                       int16_t e = speed1_wish - speed1;
                        esum1+=e;
                        motor1 = KP*e + KI*PID_T*esum1 + KD/PID_T*(e - eold1);
                        eold1 = e;
 
-                        if (motor1 > 255) motor1 = 255;
+                       if (motor1 > 0 && speed1_wish < 0) motor1=PWM_BREAK;
+                       else if (motor1 < 0 && speed1_wish > 0) motor1=PWM_BREAK;
+                       else if (motor1 > 255) motor1 = 255;
                        else if (motor1 < -255) motor1 = -255;
                }
        }
        if (motor2_mode == MOTOR_PID) {
-               if (speed2_wish == 0) {
+               if (speed2_wish != speed2_wish_old) {
+                       if (abs(speed2_wish - speed2_wish_old) > 500) esum2 = 0;
+                       speed2_wish_old = speed2_wish;
+               }
+
+               uint8_t dir_change = (speed2_wish > 0 && speed2 < 0) || (speed2_wish < 0 && speed2 > 0); // Prevent dangerous immediate engine reverse
+               if (speed2_wish == 0 || dir_change) {
                        motor2 = 0;
                        eold2 = 0;
-                       esum2 = 0;
+                       error_state &= ~(1<<5);
                } else {
-                       int16_t e = speed2_wish - speed_r;
+                       int16_t e = speed2_wish - speed2;
                        esum2+=e;
                        motor2 = KP*e + KI*PID_T*esum2 + KD/PID_T*(e - eold2);
                        eold2 = e;
 
-                        if (motor2 > 255) motor2 = 255;
+                       if (motor2 > 0 && speed2_wish < 0) motor2=PWM_BREAK;
+                       else if (motor2 < 0 && speed2_wish > 0) motor2=PWM_BREAK;
+                       else if (motor2 > 255) motor2 = 255;
                        else if (motor2 < -255) motor2 = -255;
                }
        }
+       if (motor3_mode == MOTOR_PID) {
+               if (speed3_wish != speed3_wish_old) {
+                       if (abs(speed3_wish - speed3_wish_old) > 500) esum3 = 0;
+                       speed3_wish_old = speed3_wish;
+               }
+
+               uint8_t dir_change = (speed3_wish > 0 && speed3 < 0) || (speed3_wish < 0 && speed3 > 0); // Prevent dangerous immediate engine reverse
+               if (speed3_wish == 0 || dir_change) {
+                       motor3 = 0;
+                       eold3 = 0;
+                       error_state &= ~(1<<6);
+               } else {
+                       int16_t e = speed3_wish - speed3;
+                       esum3+=e;
+                       motor3 = KP*e + KI*PID_T*esum3 + KD/PID_T*(e - eold3);
+                       eold3 = e;
+
+                       if (motor3 > 0 && speed3_wish < 0) motor3=PWM_BREAK;
+                       else if (motor3 < 0 && speed3_wish > 0) motor3=PWM_BREAK;
+                       else if (motor3 > 255) motor3 = 255;
+                       else if (motor3 < -255) motor3 = -255;
+               }
+       }
+       if (motor4_mode == MOTOR_PID) {
+               if (speed4_wish != speed4_wish_old) {
+                       if (abs(speed4_wish - speed4_wish_old) > 500) esum4 = 0;
+                       speed4_wish_old = speed4_wish;
+               }
+
+               uint8_t dir_change = (speed4_wish > 0 && speed4 < 0) || (speed4_wish < 0 && speed4 > 0); // Prevent dangerous immediate engine reverse
+               if (speed4_wish == 0 || dir_change) {
+                       motor4 = 0;
+                       eold4 = 0;
+                       error_state &= ~(1<<7);
+               } else {
+                       int16_t e = speed4_wish - speed4;
+                       esum4+=e;
+                       motor4 = KP*e + KI*PID_T*esum4 + KD/PID_T*(e - eold4);
+                       eold4 = e;
+
+                       if (motor4 > 0 && speed4_wish < 0) motor4=PWM_BREAK;
+                       else if (motor4 < 0 && speed4_wish > 0) motor4=PWM_BREAK;
+                       else if (motor4 > 255) motor4 = 255;
+                       else if (motor4 < -255) motor4 = -255;
+               }
+       }
 }
 
 
@@ -746,6 +1041,9 @@ int main(void) {
        DDRB = (1 << 3);
        DDRC = (1 << 7) | (1 << 6) | (1 << 5) | (1 << 4) | (1 << 3) | (1 << 2);
        DDRD = (1 << 7) | (1 << 5) | (1 << 4) | (1 << 3) | (1 << 2);
+       // Pullup Diag/Enable
+       PORTB = (1 << 0) | (1 << 1) | (1 << 2);
+       PORTD = (1 << 6);
 
        bootloader = 0x00;
        setup_uart(9600);
@@ -753,16 +1051,35 @@ int main(void) {
 
        // I2C
        TWAR = 0x50;
-       TWI_RESET;
+       TWI_ACK;
 
        // Motor 1 & 2
-       // Timer 1: Fast PWM non-inverting mode, Top=256 => 15.625kHz
+       // Also used for PWM frequency TIMER1_FREQ (F_CPU/256)
+       // Timer 1: Fast PWM non-inverting mode, Top=255 => 19.531kHz
        // Prescaler=1
-       TCCR1A = (1 << COM1A1) | (1 << COM1B1) | (1 << WGM10);
+       //TCCR1A = (1 << COM1A1) | (1 << COM1B1) | (1 << WGM10);
+       // Avoid narrow spike on extreme pwm value 0 by not setting COM1*1
+       TCCR1A = (1 << WGM10);
        TCCR1B = (1 << WGM12) | (1 << CS10);
        OCR1A = 0;
        OCR1B = 0;
 
+       // Motor 3
+       // Timer 2: Fast PWM non-inverting mode, Top=255
+       // Prescaler=1
+       //TCCR2 = (1 << WGM21) | (1 << WGM20) | (1 << COM21) | (1 << CS20);
+       // Avoid narrow spike on extreme pwm value 0 by not setting COM21
+       TCCR2 = (1 << WGM21) | (1 << WGM20) | (1 << CS20);
+       OCR2 = 0;
+
+       // Motor 4
+       // Timer 0: Fast PWM non-inverting mode, Top=255
+       // Prescaler=1
+       //TCCR0 = (1 << WGM01) | (1 << WGM00) | (1 << COM01) | (1 << CS00);
+       // Avoid narrow spike on extreme pwm value 0 by not setting COM01
+       TCCR0 = (1 << WGM01) | (1 << WGM00) | (1 << CS00);
+       OCR0 = 0;
+
        printf("\r\nStart\r\n");
 
        set_sleep_mode(SLEEP_MODE_IDLE);
@@ -775,10 +1092,11 @@ int main(void) {
                        case 0xff: // Magic reg that starts the bootloader
                                if (bootloader == 0xa5) {
                                        cli();
-                                       {
-                                               void (*start)(void) = (void*)0x1800;
-                                               start();
-                                       }
+                                       // write mark to first area in eeprom
+                                       eeprom_write_byte((uint8_t*)0, 123);
+                                       eeprom_busy_wait();
+                                       // Use watchdog to restart
+                                       wdt_enable(WDTO_15MS);
                                }
                                break;
                }
@@ -793,19 +1111,33 @@ int main(void) {
                        cmd_vel.bUpdate = 0;
                        sei();
 
-                       speed_wish_right = angle*M_PI*WHEEL_DIST/2 + speed;
+                       speed_wish_right = (angle*WHEEL_DIST)/2 + speed;
                        speed_wish_left = speed*2-speed_wish_right;
 
                        speed_wish_left*=STEP_PER_M_LEFT;
                        speed_wish_right*=STEP_PER_M_RIGHT;
 
-                       speed1_wish = speed_wish_left;
-                       speed2_wish = speed_wish_right;
+                       if (aft_handicap > 0) {
+                               speed1_wish = speed_wish_left * (100-aft_handicap)/100.0;
+                               speed3_wish = speed_wish_right * (100-aft_handicap)/100.0;
+                       } else {
+                               speed1_wish = speed_wish_left;
+                               speed3_wish = speed_wish_right;
+                       }
+                       if (front_handicap > 0) {
+                               speed2_wish = speed_wish_left * (100-front_handicap)/100.0;
+                               speed4_wish = speed_wish_right * (100-front_handicap)/100.0;
+                       } else {
+                               speed2_wish = speed_wish_left;
+                               speed4_wish = speed_wish_right;
+                       }
                        motor1_mode = MOTOR_PID;
                        motor2_mode = MOTOR_PID;
+                       motor3_mode = MOTOR_PID;
+                       motor4_mode = MOTOR_PID;
                }
 
-               if (run_update >= 156) { // ~100Hz
+               if (run_update >= 195) { // TIMER1_FREQ/195 = ~100Hz
                        run_update=0;
 
                        update_pos();