m3pi.cpp

00001 #include "m3pi.h"
00002 
00003 ////////////////////////// constructor/destructor //////////////////////////////
00004 
00005 
00006 m3pi::m3pi()
00007 {
00008     _serial = new BufferedSerial(p9,p10);
00009     _reset = new DigitalOut(p8);
00010     _last_line_position = 0.0;
00011 
00012     // initialise the arrays
00013     _bar_graph[0] = ' ';
00014     for (int i = 0; i < 6; i++) {
00015         _bar_graph[i+1] = i;
00016     }
00017     for (int i = 0; i < 5; i++) {
00018         _values[i]=0;
00019     }
00020 }
00021 
00022 m3pi::~m3pi()
00023 {
00024     delete _serial;
00025     delete _reset;
00026 
00027 }
00028 
00029 /////////////////////////////// public methods /////////////////////////////////
00030 
00031 void m3pi::init()
00032 {
00033     _serial->set_baud(115200);
00034     reset();                        // hard rest of 3pi
00035     stop();                         // stop motors
00036     lcd_clear();                    // clear LCD
00037 }
00038 
00039 /////////////////////////////// serial slave commands ////////////////////////////////
00040 
00041 void m3pi::scan()
00042 {
00043     get_calibrated_values(_values);
00044 }
00045 
00046 void m3pi::get_signature(char *signature)
00047 {
00048     char buff[7];
00049     //_serial->putc(0x81);
00050     buff[1]=0x81;
00051     _serial->write(buff,1);
00052     //_serial->gets(signature,7);
00053     _serial->read(buff,7);
00054 }
00055 
00056 void m3pi::get_raw_values(unsigned int *values)
00057 {
00058         char buff[1];                       // send command
00059         
00060     while (_serial->readable() ) {  // flush buffer
00061         //_serial->getc();
00062         _serial->sync();
00063         
00064     }
00065 
00066     char vals[10];                     // array to receive 10 byte return message
00067 
00068     //_serial->putc(0x86);
00069     buff[0]=0x86;
00070     _serial->write(buff,1);
00071 
00072     for (int i=0; i < 10; i++) {
00073         //vals[i] =  _serial->getc();
00074         _serial->read(buff,1);
00075         vals[i] = buff[0];
00076     }
00077 
00078     for(int i=0; i<5; i++) {            // construct the 2-byte values
00079         values[i] = (vals[2*i+1] << 8) | vals[2*i];
00080     }
00081 }
00082 
00083 void m3pi::get_calibrated_values(unsigned int *values)
00084 {
00085     char buff[1];
00086 
00087     while (_serial->readable() ) {  // flush buffer
00088         //_serial->getc();
00089         _serial->sync();
00090     }
00091 
00092     char vals[10];                      // array to receive 10 byte return message
00093     //_serial->putc(0x87);                // send command
00094     buff[0]=0x87;
00095     _serial->write(buff,1);
00096 
00097     for (int i=0; i < 10; i++) {
00098         //vals[i] =  _serial->getc();
00099         _serial->read(buff,1);
00100         vals[i] = buff[0];
00101     }
00102 
00103     for(int i=0; i<5; i++) {            // construct the 2-byte values
00104         values[i] = (vals[2*i+1] << 8) | vals[2*i];
00105     }
00106 
00107 }
00108 
00109 float m3pi::get_trimpot_value()
00110 {
00111     char buff[1];
00112 
00113     //_serial->putc(0xB0);
00114     buff[0]=0xB0;
00115     _serial->write(buff,1);
00116 
00117     char lsb;// = _serial->getc();
00118     _serial->read(buff,1);
00119     lsb = buff[0];
00120     char msb;// = _serial->getc();
00121         _serial->read(buff,1);
00122     msb = buff[0];
00123     // trimpot value in the range 0 - 1023
00124     float value = ( msb<<8 | lsb ) / 1023.0;
00125     return value;
00126 }
00127 
00128 
00129 float m3pi::get_battery_voltage()
00130 {
00131     char buff[1];
00132     //_serial->putc(0xB1);
00133     buff[0]=0xB1;
00134     _serial->write(buff,1);
00135     char lsb;// = _serial->getc();
00136         _serial->read(buff,1);
00137     lsb = buff[0];
00138     char msb;// = _serial->getc();
00139         _serial->read(buff,1);
00140     msb = buff[0];
00141     // Battery in mV so convert to volts
00142     float voltage = ( msb<<8 | lsb ) / 1000.0;
00143     return voltage;
00144 }
00145 
00146 void m3pi::play_music(const char notes[],int length)
00147 {
00148     char buff[1];
00149 
00150     length = length < 0 ? 0 : length;
00151     length = length > 100 ? 100 : length;
00152 
00153     //_serial->putc(0xB3);
00154     buff[0]=0xB3;
00155     _serial->write(buff,1);
00156 
00157     //_serial->putc(length);
00158     buff[0]=length;
00159     _serial->write(buff,1);
00160 
00161     for (int i = 0 ; i < length ; i++) {
00162         //_serial->putc(notes[i]);
00163         buff[0]=notes[i];
00164         _serial->write(buff,1);
00165     }
00166 }
00167 
00168 void m3pi::calibrate()
00169 {
00170     char buff[1];
00171     //_serial->putc(0xB4);
00172     buff[0]=0xB4;
00173     _serial->write(buff,1);
00174 }
00175 
00176 void m3pi::reset_calibration()
00177 {
00178     char buff[1];
00179     //_serial->putc(0xB5);
00180     buff[0]=0xB5;
00181     _serial->write(buff,1);
00182 }
00183 
00184 float m3pi::get_line_position()
00185 {
00186     char buff[1];
00187     //_serial->putc(0xB6);
00188     buff[0]=0xB6;
00189     _serial->write(buff,1);
00190 
00191     char lsb;// = _serial->getc();
00192         _serial->read(buff,1);
00193     lsb = buff[0];
00194     char msb;// = _serial->getc();
00195         _serial->read(buff,1);
00196     msb = buff[0];
00197     int position = (msb<<8 | lsb);
00198 
00199     return float(position - 2000)/2000.0;
00200 }
00201 
00202 void m3pi::lcd_clear()
00203 {
00204     char buff[1];
00205     //_serial->putc(0xB7);
00206     buff[0]=0xB7;
00207     _serial->write(buff,1);
00208 }
00209 
00210 void m3pi::lcd_print(char text[],int length)
00211 {
00212     char buff[1];
00213 
00214     length = length < 0 ? 0 : length;
00215     length = length > 8 ? 8 : length;
00216 
00217     //_serial->putc(0xB8);
00218     buff[0]=0xB8;
00219     _serial->write(buff,1);
00220 
00221     //_serial->putc(length);
00222     buff[0]=length;
00223     _serial->write(buff,1);
00224 
00225     for (int i = 0 ; i < length ; i++) {
00226         //_serial->putc(text[i]);
00227         buff[0]=text[i];
00228         _serial->write(buff,1);
00229     }
00230 }
00231 
00232 void m3pi::lcd_goto_xy(int x, int y)
00233 {
00234     char buff[1];
00235     //_serial->putc(0xB9);
00236         buff[0]=0xB9;
00237     _serial->write(buff,1);
00238     //_serial->putc(x);
00239         buff[0]=x;
00240     _serial->write(buff,1);
00241    //_serial->putc(y);
00242         buff[0]=y;
00243     _serial->write(buff,1);
00244 }
00245 
00246 void m3pi::auto_calibrate()
00247 {
00248     char buff[1];
00249     //_serial->putc(0xBA);
00250         buff[0]=0xBA;
00251     _serial->write(buff,1);
00252 
00253     while(1) {  // wait for serial response
00254         if (_serial->readable()) {
00255             break;
00256         }
00257     }
00258 }
00259 
00260 /////////////////////////////// motor methods ////////////////////////////////
00261 
00262 void m3pi::left_motor(float speed)
00263 {
00264     char buff[1];
00265     // check within bounds
00266     speed = speed > 1.0 ? 1.0 : speed;
00267     speed = speed < -1.0 ? -1.0 : speed;
00268 
00269     if (speed > 0.0) {  // forward
00270         //_serial->putc(0xC1);
00271             buff[0]=0xC1;
00272     _serial->write(buff,1);
00273         char s = char(127.0*speed);
00274         //_serial->putc(s);
00275             buff[0]=s;
00276     _serial->write(buff,1);
00277     } else { // backward - speed is negative
00278         //_serial->putc(0xC2);
00279             buff[0]=0xC2;
00280     _serial->write(buff,1);
00281         char s = char(-127.0*speed);
00282         //_serial->putc(s);
00283             buff[0]=s;
00284     _serial->write(buff,1);
00285     }
00286 
00287 }
00288 
00289 void m3pi::right_motor(float speed)
00290 {
00291     char buff[1];
00292     // check within bounds
00293     speed = speed > 1.0 ? 1.0 : speed;
00294     speed = speed < -1.0 ? -1.0 : speed;
00295 
00296     if (speed > 0.0) {  // forward
00297         //_serial->putc(0xC5);
00298             buff[0]=0xC5;
00299     _serial->write(buff,1);
00300         char s = char(127.0*speed);
00301         //_serial->putc(s);
00302             buff[0]=s;
00303     _serial->write(buff,1);
00304     } else { // backward - speed is negative
00305         //_serial->putc(0xC6);
00306             buff[0]=0xC6;
00307     _serial->write(buff,1);
00308         char s = char(-127.0*speed);
00309         //_serial->putc(s);
00310             buff[0]=s;
00311     _serial->write(buff,1);
00312     }
00313 
00314 }
00315 
00316 // speeds from -1.0 to 1.0 (0 is stop)
00317 void m3pi::motors(float left_speed,float right_speed)
00318 {
00319     left_motor(left_speed);
00320     right_motor(right_speed);
00321 }
00322 
00323 void m3pi::stop()
00324 {
00325     left_motor(0.0);
00326     right_motor(0.0);
00327 }
00328 
00329 // speed in range 0.0 to 1.0
00330 void m3pi::forward(float speed)
00331 {
00332     speed = speed > 1.0 ? 1.0 : speed;
00333     speed = speed < 0.0 ? 0.0 : speed;
00334 
00335     left_motor(speed);
00336     right_motor(speed);
00337 }
00338 
00339 // speed in range 0 to 1.0
00340 void m3pi::reverse(float speed)
00341 {
00342     speed = speed > 1.0 ? 1.0 : speed;
00343     speed = speed < 0.0 ? 0.0 : speed;
00344 
00345     left_motor(-speed);
00346     right_motor(-speed);
00347 }
00348 
00349 void m3pi::spin_right(float speed)
00350 {
00351     speed = speed > 1.0 ? 1.0 : speed;
00352     speed = speed < 0.0 ? 0.0 : speed;
00353 
00354     left_motor(speed);
00355     right_motor(-speed);
00356 }
00357 
00358 void m3pi::spin_left(float speed)
00359 {
00360     speed = speed > 1.0 ? 1.0 : speed;
00361     speed = speed < 0.0 ? 0.0 : speed;
00362 
00363     left_motor(-speed);
00364     right_motor(speed);
00365 }
00366 
00367 ////////////////////////////////////////////////////////////////////////////////
00368 
00369 void m3pi::display_battery_voltage(int x,int y)
00370 {
00371     float voltage = get_battery_voltage();
00372 
00373     char buffer[8];
00374     sprintf(buffer,"%3.1f V",voltage);
00375 
00376     lcd_goto_xy(x,y);
00377     lcd_print(buffer,5);
00378 }
00379 
00380 void m3pi::display_signature(int x,int y)
00381 {
00382     char buffer[7]; // including NULL terminator
00383     
00384     //_serial->putc(0x81);
00385         buffer[0]=0x81;
00386     _serial->write(buffer,1);
00387     
00388     
00389     //_serial->gets(buffer,7);
00390     _serial->read(buffer,7);
00391 
00392     lcd_goto_xy(x,y);
00393     lcd_print(buffer,6);
00394 }
00395 
00396 void m3pi::display_sensor_values(unsigned int values[],int y)
00397 {
00398     // initialise array to ASCII '0'
00399     lcd_goto_xy(1,y);
00400 
00401     char sensor_values[5];
00402 
00403     // loop through sensor
00404     for (int sensor = 0 ; sensor < 5 ; sensor++) {
00405         // get the value and put it in the correct bin
00406         // (7 bins in the range 0 to 1000
00407         char value = char(values[sensor]/(1000.0/7.0));
00408         // use the bin to select the bar graph icon to display
00409         sensor_values[sensor] = _bar_graph[value];
00410     }
00411 
00412     lcd_print(sensor_values,5);
00413 
00414 }
00415 
00416 void m3pi::display_data()
00417 {
00418     display_sensor_values(_values,1);
00419 
00420     char buffer[8]= {0};
00421     sprintf(buffer,"% .3f",_last_line_position);
00422     lcd_goto_xy(0,0);
00423     lcd_print(buffer,6);
00424 
00425 }
00426 
00427 unsigned int m3pi::get_sensor_array_value(unsigned int values[])
00428 {
00429     unsigned int value = 0;
00430 
00431     // loop through each bit, starting from PC4
00432     for (int i = 4; i >= 0; i--) {
00433 
00434         unsigned int weight = pow(2.0,4-i);
00435 
00436         // check if over threshold
00437         if (values[i] > 500) {
00438             // add equivalent binary weight to value
00439             value += weight;
00440         }
00441 
00442     }
00443 
00444     return value;
00445 }
00446 
00447 float m3pi::calc_line_position(unsigned int values[])
00448 {
00449     // calculate weighted average
00450     unsigned int value =
00451         (0*values[0]+1e3*values[1]+2e3*values[2]+3e3*values[3]+4e3*values[4])/
00452         (values[0]+values[1]+values[2]+values[3]+values[4]);
00453 
00454     // scale to between -1.0 and 1.0
00455     float position = (int(value) - 2000)/2000.0;
00456 
00457     float is_on_line = false;
00458 
00459     // loop through and check if any sensor reading is above the threshold
00460     for (int i = 0; i<5; i++) {
00461         if (values[i] > 500) {
00462             is_on_line = true;
00463         }
00464     }
00465 
00466     // update last line position if over line
00467     if (is_on_line) {
00468         _last_line_position = position;
00469     }
00470 
00471     // if not on line then the last line position will have the last value when over line
00472     return _last_line_position;
00473 }
00474 
00475 float m3pi::read_line()
00476 {
00477     return calc_line_position(_values);
00478 }
00479 
00480 
00481 
00482 /////////////////////////////// private methods ////////////////////////////////
00483 
00484 void m3pi::reset()
00485 {
00486     // pulse the reset line (active-high)
00487     _reset->write(1);
00488     ThisThread::sleep_for(100ms);
00489     _reset->write(0);
00490     ThisThread::sleep_for(100ms);
00491 }