Robot that balances on two wheels

Dependencies:   LSM9DS0 mbed

Revision:
3:89e4ed1324bb
Parent:
2:89ada0b0b923
Child:
4:51ea148fc592
diff -r 89ada0b0b923 -r 89e4ed1324bb main.cpp
--- a/main.cpp	Tue Apr 28 02:18:55 2015 +0000
+++ b/main.cpp	Wed Apr 29 20:10:33 2015 +0000
@@ -29,7 +29,7 @@
 // Constants
 #define LSM9DS0_XM_ADDR  0x1D                                   // Would be 0x1E if SDO_XM is LOW
 #define LSM9DS0_G_ADDR   0x6B                                   // Would be 0x6A if SDO_G is LOW
-//#define DEBUG                                                   // Comment this out for final version
+//#define DEBUG                                                  // Comment this out for final version
 
 //////////////////////////////////////////////////////////////////
 // I/O and object instatiation
@@ -41,22 +41,19 @@
 DigitalOut NmotorDirRight(p25);                                 // Usually inverse of motorDirRight
 LSM9DS0 imu(p9, p10, LSM9DS0_G_ADDR, LSM9DS0_XM_ADDR);          // Creates on object for IMU
 Ticker start;                                                   // Initialize ticker to call control function
-Ticker GUI;
-//Serial xbee(p13, p14);                                          // Creates virtual serial for xbee
-Serial pc(USBTX,USBRX);// later only use xbee
-Timer t; //debugging only
-DigitalOut led1(LED1); // debug only
-DigitalOut led2(LED2); // debug only
-DigitalOut led3(LED3); // debug only
-typedef union _data { // maybe there is a better way?
+Ticker GUI;                                                     // Ticker that calls the updateGUI
+DigitalOut led1(LED1);                                          // Use LED1 to provide some runtime info
+Serial xbee(p13,p14);                                             // Create serial port for Xbee
+
+typedef union _data {                                           // Typedef so we can jump from chars to floats
     float f;
     char chars[4];
-    int i; // added to receive integers
+    int i;
 } myData;
 
-
 //////////////////////////////////////////////////////////////////
 // Globals // double battery, lab floor: 67/100/600/160 cutoff ..35
+// positive turns
 float kp = 59; //98                                                 // 145 Proportional gain kU 400-500
 float kd = 105;  //200                                               // Derivative gain
 float ki = 670;   //985                                             // Integrative gain
@@ -70,33 +67,32 @@
 float dAngle = 0;                                               // Derivative value for angle, angular velocity, how fast angle is changing
 float pAngle = 0;                                               // Proportional value for angle, current angle (best measurement)
 float desiredAngle=0;                                           // Setpoint. Set unequal zero to drive
-float turnspeed=0;                                              // positive turns
-myData bytes;
+float turnspeed=0;                                              // Makes the robot turn
+myData bytes;                                                   // Used to convert received/sent chars to ints and floats
+
 
 //////////////////////////////////////////////////////////////////
 // Function Prototypes
 void drive(float);                                              // Function declaration for driving the motors
 void calibrate();                                               // Function to calibrate gyro and accelerometer
 void control();                                                 // Function implementing PID control
-void callback();                                                // Interrupt triggered function for serial communication
-void sendFloatAsBytes();
 void updateGUI();
+void checkValues();
+
 //////////////////////////////////////////////////////////////////
 // Main function
 int main()
 {
-
-    led1=0;//debug only
+    led1=0;                                                     // Turn led off
     uint16_t status = imu.begin();                              // Use the begin() function to initialize the LSM9DS0 library.
-    pc.baud(115200);//pretty high, check if lower possible
-    pc.attach(&callback);                                       // Attach interrupt to serial communication
+    xbee.baud(115200);                                            // Baudrate. Pretty high, check if lower possible
     calibrate();                                                // Calibrate gyro and accelerometer
     start.attach(&control, 0.01);                               // Looptime 10ms ca. 100Hz
-    GUI.attach(&updateGUI, 0.5); // update GUI twice a second
+    GUI.attach(&updateGUI, 0.5);                                // Update GUI twice a second
 
-    while(1) { // Stay in this loop forever
-        led1=!led1;
-        wait_ms(500); // blink twice a second
+    while(1) {                                                  // Stay in this loop forever
+        led1=!led1;                                             // Blink led1 to make sure the loop is running
+        wait_ms(500);                                           // Looptime 500ms
     }
 }
 
@@ -119,6 +115,7 @@
         else if(speed>1) speed=1;                               // Cap if overshoot
     } else speed=0;                                             // If we've fallen over or are steady on top
     drive(speed);                                               // Write speed to the motors
+    checkValues();                                             // Checks if we need to update some values
 
 }
 
@@ -180,86 +177,85 @@
     gyroBias=gyroBias/100;                                      // Convert sum to average
 }
 
-/////////////////////////////////////////////////////////////////
-// Callback function to change values/gains
-void callback()
+
+///////////////////////////////////////////////////////////////////
+// updateGUI(), triggered by ticker GUI ever 0.5s, sends data to xbee
+void updateGUI()
 {
-    led2=!led2; // Blink led2 so we know what's happening
-    char buffer[24]; //create a buffer
-    int i=0;
-    while(pc.readable()) { // read the whole damn thing
-        buffer[i]=pc.getc();
-        i++;
-    }
-// update kp
-    bytes.chars[0]=buffer[0];
-    bytes.chars[1]=buffer[1];
-    bytes.chars[2]=buffer[2];
-    bytes.chars[3]=buffer[3];
-    kp=bytes.i;
-// update ki
-    bytes.chars[0]=buffer[4];
-    bytes.chars[1]=buffer[5];
-    bytes.chars[2]=buffer[6];
-    bytes.chars[3]=buffer[7];
-    ki=bytes.i;
-// update kd
-    bytes.chars[0]=buffer[8];
-    bytes.chars[1]=buffer[9];
-    bytes.chars[2]=buffer[10];
-    bytes.chars[3]=buffer[11];
-    kd=bytes.i;
-// update OVERALL_SCALAR
-    bytes.chars[0]=buffer[12];
-    bytes.chars[1]=buffer[13];
-    bytes.chars[2]=buffer[14];
-    bytes.chars[3]=buffer[15];
-    OVERALL_SCALAR=bytes.i;
-// update turnspeed
-    bytes.chars[0]=buffer[16];
-    bytes.chars[1]=buffer[17];
-    bytes.chars[2]=buffer[18];
-    bytes.chars[3]=buffer[19];
-    turnspeed=bytes.i;
-// update desiredAngle
-    bytes.chars[0]=buffer[20];
-    bytes.chars[1]=buffer[21];
-    bytes.chars[2]=buffer[22];
-    bytes.chars[3]=buffer[23];
-    desiredAngle=bytes.i;
-
-
-    // Update kp min: 0 max: 3000
-    // Update kd min: 0 max: 3000
-    // Update ki min: 0 max: 3000
-    // Update OVERALL_SCALAR  min: 0 max: 3000
-    // Update turnspeed min: -0.5 max: 0.5
-    // Update desiredAngle min: -3 max: 3
-    // Send pAngle BETTER: kp*pAngle
-    // Send dAngle BETTER: kd*dAngle
-    // Send iAngle BETTER: kd*dAngle
+    xbee.putc('*');                                               // Send data validity value
+    bytes.f = accBias;                                          // Send accBias
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = gyroBias;                                         // Send gyroBias
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = pAngle;                                           // Send P Angle
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = imu.gx;                                           // Send current angular velocity
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = turnspeed;                                        // Send turn speed
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = pAngle * kp;                                      // Send P Value
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = iAngle * ki;                                      // Send I Value
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    bytes.f = dAngle * kd;                                      // Send D Value
+    xbee.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
+    xbee.putc('\n');                                              // Send delimiting character
 }
 //////////////////////////////////////////////////////////////////
-// maybe get rid of this function and put it into updateGUI to run faster
-void sendFloatAsBytes()
-{
-    pc.printf("%c%c%c%c", bytes.chars[0], bytes.chars[1], bytes.chars[2], bytes.chars[3]);
-}
-
-///////////////////////////////////////////////////////////////////
-// triggered by ticker GUI ever 0.5s, sends data to PC
-void updateGUI()
+// checkValues() updates globals received from xbee
+void checkValues()
 {
-    led3=!led3; // blink so we know what's going on
-    pc.putc('6'); // 6 is for pTerm
-    bytes.f=pAngle; // later kp*pAngle
-    sendFloatAsBytes();
-    wait_us(10); // waiting a little bit is key
-    pc.putc('7');
-    bytes.f=iAngle;
-    sendFloatAsBytes();
-    wait_us(10);
-    pc.putc('8');
-    bytes.f=dAngle;
-    sendFloatAsBytes();
+    int i=0;                                                        // Integer needed for looping through input buffer
+    char buffer[6];                                                 // Buffer to hold all the received data
+
+    while(xbee.readable()) {                                          // As long as there is stuff in the buffer
+        buffer[i++]=xbee.getc();                                      // Read from serial
+    }
+
+    if(buffer[0]== '*') {                                           // Check for 'start' character
+        switch(buffer[1]) {                                         // Switch depending on what value we update
+            case '1':                                               // Updating kp
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                kp=bytes.f;
+                break;
+            case '2':                                               // Updating kd
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                kd=bytes.f;
+                break;
+            case '3':                                               // Updating ki
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                ki=bytes.f;
+                break;
+            case '4':                                                // Updating OVERALL_SCALAR
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                OVERALL_SCALAR=bytes.f;
+                break;
+            case '5':                                                // Updating desiredAngle
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                desiredAngle=bytes.f;
+                break;
+            case '6':                                               // Updating turnspeed
+                bytes.chars[0] = buffer[2];
+                bytes.chars[1] = buffer[3];
+                bytes.chars[2] = buffer[4];
+                bytes.chars[3] = buffer[5];
+                turnspeed=bytes.f;
+        }
+    }
+
 }
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