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Wifi Controlled Robot is done as a mini project (Lab4) for ECE 4180 class (Georgia Tech). Robot is assembled in Sparkfun's Shadow chasis robot kit. This robot takes the command from the webpage to move forward, reverse without colliding. The distance sensor is used as a mechanism for collision detection and play a short beep sound. It turn 90 degree with magnetometer when the turn command is sent.
Dependencies: Motordriver mbed
Showing the setup and calibration: Part1
In this part the Wifi setups and attains an IP address so we can control it through a webpage on our phone/PC.
After it obtains an IP address it calibrates the IMU so we can have accurate compass headings for precise turns.
The parts that we use are as follows:
- Mbed
- 2 DC motors
- H-Bridge (to drive the DC motors)
- Speaker
- Class D Amp (to drive the Speaker)
- IMU (use the magnometer for compass headings)
- Wifi card (ESP8266)
Showing webpage functionality and Robot Functionality: In this part we demonstrate the functionality of the robot and the webpage to control it.
Final Code
[Repository '/teams/Prana-Koirala/code/Wifi_controlled_Robot_ECE4180/docs/tip/main_8cpp_source.html' not found]
main.cpp
- Committer:
- pkoirala3
- Date:
- 2017-03-13
- Revision:
- 3:fff9904d2ecb
- Parent:
- 1:bbe16318d747
- Child:
- 4:166570fa7fda
File content as of revision 3:fff9904d2ecb:
#include "mbed.h" #include "motordriver.h" #include "ultrasonic.h" #include "LSM9DS1.h" #define PI 3.14159 #define DECLINATION -4.94 // Declination (degrees) in Atlanta,GA. DigitalOut ledFwd(p8); DigitalOut ledRev(p11); Motor A(p26, p16, p25, 1); // pwm, fwd, rev, can brake Motor B(p21, p22, p23, 1); // pwm, fwd, rev, can brake Serial pc(USBTX, USBRX); Serial esp(p28, p27); // tx, rx PwmOut mySpeaker(p24); // LSM9DS1 IMU(p9, p10, 0xD6, 0x3C); AnalogIn DistSensorFwd(p19); AnalogIn DistSensorRev(p20); // variables for sending/receiving data over serial volatile int tx_in=0; volatile int tx_out=0; volatile int rx_in=0; volatile int rx_out=0; const int buffer_size = 4095; char tx_buffer[buffer_size+1]; char rx_buffer[buffer_size+1]; void Tx_interrupt(); void Rx_interrupt(); void send_line(); void read_line(); int DataRX; int update; char cmdbuff[1024]; char replybuff[4096]; char webdata[4096]; char webbuff[4096]; char stateBuff[50]; void SendCMD(),getreply(),ReadWebData(),startserver(); void ImuCheck(), ObjDetect(float); char rx_line[1024]; int port = 80; // set server port int SERVtimeout = 5; // set server timeout in seconds in case link breaks. int main() { pc.baud(9600); esp.baud(9600); esp.attach(&Rx_interrupt, Serial::RxIrq); //serial interrupt to receive data esp.attach(&Tx_interrupt, Serial::TxIrq); //serial interrupt to transmit data startserver(); wait(0.01); DataRX=0; mySpeaker.period(1.0/200.0); // 500hz period A.stop(0.0); B.stop(0.0); /* IMU.begin(); IMU.calibrate(1); IMU.calibrateMag(0); pc.printf("Final Calibration done, prana"); */ while(1) { if(DataRX==1) { ReadWebData(); esp.attach(&Rx_interrupt, Serial::RxIrq); } float stateA = A.state(); float stateB = B.state(); char temp_buff[50]; if(abs(stateA) > 1 && abs(stateB) > 1) strcpy(temp_buff, "Robot Stopped!"); else if((stateA > 0 && stateA <= 1)&&(stateB > 0 && stateB <= 1)) { // obstacle within 10 cm and robot is still moving float Dist = DistSensorFwd; ObjDetect(Dist); strcpy(temp_buff, "Robot Moving Forward!"); } else if((stateA < 0 && stateA >= -1)&&(stateB < 0 && stateB >= -1)) { // If moving rev float Dist = DistSensorRev; ObjDetect(Dist); strcpy(temp_buff, "Robot Moving Reverse!"); } else if(abs(stateA) > 0 && abs(stateA) <= 1 && abs(stateB) > 1) { strcpy(temp_buff, "Robot turning right!"); } else if(abs(stateB) > 0 && abs(stateB) <= 1 && abs(stateA) > 1) { strcpy(temp_buff, "Robot turning left!"); } else strcpy(temp_buff, "Error getting Robot state"); if(update==1) { // update the state of Robot in webpage sprintf(stateBuff, "%s",temp_buff); sprintf(cmdbuff, "BotState=\"%s\"\r\n",stateBuff); SendCMD(); getreply(); update=0; } } } // Reads and processes GET and POST web data void ReadWebData() { wait_ms(200); esp.attach(NULL,Serial::RxIrq); DataRX=0; memset(webdata, '\0', sizeof(webdata)); strcpy(webdata, rx_buffer); memset(rx_buffer, '\0', sizeof(rx_buffer)); rx_in = 0; rx_out = 0; // check web data for form information if( strstr(webdata, "check=BotFwd") != NULL ) { if(abs(A.state()) <= 1) A.stop(0.0); if(abs(B.state()) <= 1) B.stop(0.0); A.speed(0.75); B.speed(0.75); ledRev = 0; ledFwd = 1; } if( strstr(webdata, "check=BotRev") != NULL ) { if(abs(A.state()) <= 1) A.stop(0.0); if(abs(B.state()) <= 1) B.stop(0.0); A.speed(-0.75); B.speed(-0.75); ledFwd = 0; ledRev = 1; } if( strstr(webdata, "check=BotStop") != NULL ) { A.stop(0.0); B.stop(0.0); ledFwd = 0; ledRev = 0; } if( strstr(webdata, "check=BotLeft") != NULL ) { B.stop(0.0); A.speed(0.75); // ImuCheck(); wait(1.0); A.stop(0.0); } if( strstr(webdata, "check=BotRight") != NULL ) { A.stop(0.0); B.speed(0.5); // ImuCheck(); wait(1.0); B.stop(0.0); } if( strstr(webdata, "POST") != NULL ) { // set update flag if POST request update=1; } if( strstr(webdata, "GET") != NULL && strstr(webdata, "favicon") == NULL ) { // set update flag for GET request but do not want to update for favicon requests update=1; } } // Starts webserver void startserver() { pc.printf("Resetting ESP Device....\r\n"); strcpy(cmdbuff,"node.restart()\r\n"); SendCMD(); wait(2); getreply(); pc.printf("\nStarting Server.....\r\n> "); // initial values sprintf(cmdbuff, "BotState=\"%s\"\r\n",stateBuff); SendCMD(); getreply(); wait(0.5); //create server sprintf(cmdbuff, "srv=net.createServer(net.TCP,%d)\r\n",SERVtimeout); SendCMD(); getreply(); wait(0.5); strcpy(cmdbuff,"srv:listen(80,function(conn)\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff,"conn:on(\"receive\",function(conn,payload) \r\n"); SendCMD(); getreply(); wait(0.3); //print data to mbed strcpy(cmdbuff,"print(payload)\r\n"); SendCMD(); getreply(); wait(0.2); //web page data strcpy(cmdbuff,"conn:send('<!DOCTYPE html><html><body><h1>ESP8266 Mbed IoT Web Controller</h1>')\r\n"); SendCMD(); getreply(); wait(0.4); strcpy(cmdbuff,"conn:send('<br>Current State of Robot: '..BotState..'<br><hr>')\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff,"conn:send('<form method=\"POST\"')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><input type=\"radio\" name=\"check\" value=\"BotFwd\"> Move Robot Forward')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><input type=\"radio\" name=\"check\" value=\"BotRev\"> Move Robot Reverse')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><input type=\"radio\" name=\"check\" value=\"BotStop\"> Stop Robot')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><input type=\"radio\" name=\"check\" value=\"BotLeft\"> Turn Robot Left')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><input type=\"radio\" name=\"check\" value=\"BotRight\"> Turn Robot Right')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff,"conn:send('<p><input type=\"submit\" value=\"Send to Robot\"></form>')\r\n"); SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "conn:send('<p><h2>How to use:</h2><ul><li>Select a radiobutton </li><li>Click Send to Robot button</li></ul></body></html>')\r\n"); SendCMD(); getreply(); wait(0.5); // end web page data strcpy(cmdbuff, "conn:on(\"sent\",function(conn) conn:close() end)\r\n"); // close current connection SendCMD(); getreply(); wait(0.3); strcpy(cmdbuff, "end)\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "end)\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "tmr.alarm(0, 1000, 1, function()\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "if wifi.sta.getip() == nil then\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "print(\"Connecting to AP...\\n\")\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "else\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff, "ip, nm, gw=wifi.sta.getip()\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff,"print(\"IP Address: \",ip)\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff,"tmr.stop(0)\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff,"end\r\n"); SendCMD(); getreply(); wait(0.2); strcpy(cmdbuff,"end)\r\n"); SendCMD(); getreply(); wait(0.2); pc.printf("\n\nReady to go .....\r\n\n"); } // ESP Command data send void SendCMD() { int i; char temp_char; bool empty; i = 0; // Start Critical Section - don't interrupt while changing global buffer variables NVIC_DisableIRQ(UART1_IRQn); empty = (tx_in == tx_out); while ((i==0) || (cmdbuff[i-1] != '\n')) { // Wait if buffer full if (((tx_in + 1) % buffer_size) == tx_out) { // End Critical Section - need to let interrupt routine empty buffer by sending NVIC_EnableIRQ(UART1_IRQn); while (((tx_in + 1) % buffer_size) == tx_out) { } // Start Critical Section - don't interrupt while changing global buffer variables NVIC_DisableIRQ(UART1_IRQn); } tx_buffer[tx_in] = cmdbuff[i]; i++; tx_in = (tx_in + 1) % buffer_size; } if (esp.writeable() && (empty)) { temp_char = tx_buffer[tx_out]; tx_out = (tx_out + 1) % buffer_size; // Send first character to start tx interrupts, if stopped esp.putc(temp_char); } // End Critical Section NVIC_EnableIRQ(UART1_IRQn); return; } // Get Command and ESP status replies void getreply() { read_line(); sscanf(rx_line,replybuff); } // Read a line from the large rx buffer from rx interrupt routine void read_line() { int i; i = 0; // Start Critical Section - don't interrupt while changing global buffer variables NVIC_DisableIRQ(UART1_IRQn); // Loop reading rx buffer characters until end of line character while ((i==0) || (rx_line[i-1] != '\r')) { // Wait if buffer empty if (rx_in == rx_out) { // End Critical Section - need to allow rx interrupt to get new characters for buffer NVIC_EnableIRQ(UART1_IRQn); while (rx_in == rx_out) { } // Start Critical Section - don't interrupt while changing global buffer variables NVIC_DisableIRQ(UART1_IRQn); } rx_line[i] = rx_buffer[rx_out]; i++; rx_out = (rx_out + 1) % buffer_size; } // End Critical Section NVIC_EnableIRQ(UART1_IRQn); rx_line[i-1] = 0; return; } // Interupt Routine to read in data from serial port void Rx_interrupt() { DataRX=1; // Loop just in case more than one character is in UART's receive FIFO buffer // Stop if buffer full while ((esp.readable()) && (((rx_in + 1) % buffer_size) != rx_out)) { rx_buffer[rx_in] = esp.getc(); // Uncomment to Echo to USB serial to watch data flow pc.putc(rx_buffer[rx_in]); rx_in = (rx_in + 1) % buffer_size; } return; } // Interupt Routine to write out data to serial port void Tx_interrupt() { // Loop to fill more than one character in UART's transmit FIFO buffer // Stop if buffer empty while ((esp.writeable()) && (tx_in != tx_out)) { esp.putc(tx_buffer[tx_out]); tx_out = (tx_out + 1) % buffer_size; } return; } // To make Robot Turn approximately 90 degree using IMU mag void ImuCheck() { bool rotFlag = true; IMU.readMag(); float initial_heading; float mx = -1*IMU.mx; float my = IMU.my; if(my == 0.0) initial_heading = (mx < 0.0) ? 180.0 : 0.0; else initial_heading = atan2(mx,my)*360.0/(2.0*PI); initial_heading -= DECLINATION; if(initial_heading>180.0) initial_heading = initial_heading - 360.0; else if(initial_heading<0) initial_heading += 360.0; while(rotFlag) { IMU.readMag(); float mx = -1*IMU.mx; float my = IMU.my; float heading; if (my == 0.0) heading = (mx < 0.0) ? 180.0 : 0.0; else heading = atan2(mx, my)*360.0/(2.0*PI); heading -= DECLINATION; //correct for geo location if(heading>180.0) heading = heading - 360.0; else if(heading<0.0) heading += 360.0; if(abs(heading - initial_heading) > 90) rotFlag = 1; } } // Checking for obstacles in the way while moving Fwd and Rev void ObjDetect(float currDist) { if(currDist <= 0.5f) { A.stop(0.0); B.stop(0.0); ledFwd = 0; ledRev = 0; mySpeaker = 0.5; // Play Beep sound wait(1.0); mySpeaker=0.0; // turn off audio } }