i2c.cpp

00001 /* University of York Robotics Laboratory PsiSwarm Library: I2C Source File
00002  *
00003  * File: i2c.cpp
00004  *
00005  * (C) Dept. Electronics & Computer Science, University of York
00006  * James Hilder, Alan Millard, Homero Elizondo, Jon Timmis
00007  *
00008  * PsiSwarm Library Version: 0.3
00009  *
00010  * October 2015
00011  *
00012  */
00013 
00014 #include "psiswarm.h"
00015 
00016 char gpio_byte0;
00017 char gpio_byte1;
00018 char user_id_set = 0;
00019 char wheel_enc_set = 0;
00020 char switch_set = 0;
00021 
00022 char emitter_byte = 0x00;
00023 
00024 Timeout update_timeout;
00025 
00026 char test;
00027 
00028 char get_dc_status()
00029 {
00030     IF_read_aux_ic_data();
00031     return status_dc_in;
00032 }
00033 
00034 void IF_set_IR_emitter_output(char emitter, char state)
00035 {
00036     if(emitter <3) {
00037         if(state == 0) {
00038             char shift = 1 << emitter;
00039             emitter_byte &= (0xFF - shift);
00040         }
00041         if(state == 1) {
00042             char shift = 1 << emitter;
00043             emitter_byte |= shift;
00044         }
00045         char data[2];
00046         data [0] = 0x0A;  //Write to OLAT register
00047         data [1] = emitter_byte;  //GP0-3 are outputs on aux expansion IC
00048         //pc.printf("%c\n", emitter_byte);
00049         primary_i2c.write(AUX_IC_ADDRESS,data,2,false);
00050     }
00051 }
00052 
00053 void IF_set_base_LED(char state)
00054 {
00055     if(state == 0) {
00056         emitter_byte &= 0xF7;
00057     } else emitter_byte |= 0x08;
00058     char data[2];
00059     data [0] = 0x0A;  //Write to OLAT register
00060     data [1] = emitter_byte;  //GP0-3 are outputs on aux expansion IC
00061     primary_i2c.write(AUX_IC_ADDRESS,data,2,false);
00062 
00063 }
00064 
00065 unsigned short IF_read_IR_adc_value(char adc, char index)
00066 {
00067     char address = ADC1_ADDRESS;
00068     if(adc == 2) address=ADC2_ADDRESS;
00069     // Returns the raw sensor value for the IR sensor defined by index (range 0-7).
00070     short value = 0;
00071     // Read a single value from the ADC
00072     if(index<8) {
00073         char apb[1];
00074         char data[2];
00075         switch(index) {
00076             case 0:
00077                 apb[0]=0x80;
00078                 break;
00079             case 1:
00080                 apb[0]=0x90;
00081                 break;
00082             case 2:
00083                 apb[0]=0xA0;
00084                 break;
00085             case 3:
00086                 apb[0]=0xB0;
00087                 break;
00088             case 4:
00089                 apb[0]=0xC0;
00090                 break;
00091             case 5:
00092                 apb[0]=0xD0;
00093                 break;
00094             case 6:
00095                 apb[0]=0xE0;
00096                 break;
00097             case 7:
00098                 apb[0]=0xF0;
00099                 break;
00100         }
00101         primary_i2c.write(address,apb,1,false);
00102         primary_i2c.read(address,data,2,false);
00103         value=((data[0] % 16)<<8)+data[1];
00104         if(value > 4096) value=4096;
00105         value=4096-value;
00106     }
00107     return value;
00108 }
00109 
00110 char IF_setup_led_expansion_ic(void)
00111 {
00112     //LED expansion IC is PCA9555
00113     //Address is 0100 001x (0x42) {defined by LED_IC_ADDRESS}
00114     //All 16 entries are outputs as they drive LEDs; the relevant registers are 2&3 (output port registers) and 6&7 (config. registers: a 0=output)
00115     //Message structure: {Address-RW}{Command}{Port 0}{Port 1}
00116     //Command bytes: 00000010 (0x02) = Write to output port
00117     //Command bytes: 00000110 (0x06) = Write to config registers
00118     //Note that for the LEDs, 0 = on, 1 = off
00119     //Port 0 = LED 1:4 Red:Green
00120     //Port 1 = LED 5:8 Red:Green
00121     char data [3];
00122     data [0] = 0x06;    //Write config registers
00123     data [1] = 0x00;    //All 8 pins in port 0 are outputs (0)
00124     data [2] = 0x00;    //All 8 pins in port 1 are outputs (0)
00125     primary_i2c.write(LED_IC_ADDRESS,data,3,false);
00126 
00127     //Turn all LEDs on
00128     data [0] = 0x02;    //Write to output port
00129     data [1] = 0x00;    //Enable LED1-4 (both colours)
00130     data [2] = 0x00;    //Enable LED5-8 (both colours)
00131     primary_i2c.write(LED_IC_ADDRESS,data,3,false);
00132 
00133     wait(0.05);
00134     //Turn all LEDs off
00135     data [0] = 0x02;    //Write to output port
00136     data [1] = 0xFF;    //Enable LED1-4 (both colours)
00137     data [2] = 0xFF;    //Enable LED5-8 (both colours)
00138     return primary_i2c.write(LED_IC_ADDRESS,data,3,false);
00139 }
00140 
00141 //Returns 0 if successful, 1 if test mode button pressed
00142 void IF_setup_gpio_expansion_ic(void)
00143 {
00144     //Main GPIO expansion IC is PCA9555
00145     //Address is 0100 000x (0x40) {defined by GPIO_IC_ADDRESS}
00146     //All 16 entries are inputs; the relevant registers are 0&1 (input port registers), 4&5 (polarity inv. registers) and 6&7 (config. registers: a 0=output)
00147     //Message structure: {Address-RW}{Command}{Port 0}{Port 1}
00148     //Command bytes: 00000010 (0x02) = Write to output port
00149     //Command bytes: 00000110 (0x06) = Write to config registers
00150     //Note that for the LEDs, 0 = on, 1 = off
00151     //Port 0 = PGDL; PGDR; PGDIR; UP; DOWN; LEFT; RIGHT; CENTER
00152     //Port 1 = ENC_LA; ENC_LB; ENC_RA; ENC_RB; ID0; ID1; ID2; ID3
00153     char data [3];
00154     char okay = 1;
00155     data [0] = 0x06;    //Write config registers
00156     data [1] = 0xFF;    //All 8 pins in port 0 are inputs (1)
00157     data [2] = 0xFF;    //All 8 pins in port 1 are inputs (1)
00158     if(primary_i2c.write(GPIO_IC_ADDRESS,data,3,false) != 0) {
00159         system_warnings += 2;
00160         okay = 0;
00161         debug("- WARNING: No I2C acknowledge for main GPIO IC\n");
00162         if(HALT_ON_GPIO_ERROR){
00163             debug("- PROGRAM HALTED.  Check that robot is switched on!\n");
00164             while(1){
00165                mbed_led1=1;
00166                mbed_led2=1;
00167                mbed_led3=0;
00168                mbed_led4=0;
00169                wait(0.25); 
00170                mbed_led1=0;
00171                mbed_led2=0;
00172                mbed_led3=1;
00173                mbed_led4=1;
00174                wait(0.25);   
00175             }   
00176         }
00177     }
00178     //Set all inputs to polarity-inverted (so a logic low = 1)
00179     data [0] = 0x04;    //Write to polarity inversion ports
00180     data [1] = 0xF8;    //Invert polarity of all switch input bits in input port 0 [but not power-good inputs]
00181     data [2] = 0xFF;    //Invert polarity of all bits in input port 1
00182     primary_i2c.write(GPIO_IC_ADDRESS,data,3,false);
00183 
00184     wait(0.01);
00185 
00186     //Read data
00187     char read_data[2];
00188     char command[1]; //Command to read from input port 0
00189     command[0]=0;
00190     primary_i2c.write(GPIO_IC_ADDRESS,command,1,false);
00191     primary_i2c.read(GPIO_IC_ADDRESS,read_data,2,false);
00192     gpio_byte0 = read_data[0];
00193     //char ret_val = (gpio_byte0 & 0xF8) >> 3;  //Returns a >0 value if a button is being pushed
00194     gpio_byte1 = read_data[1];
00195     if(okay && testing_voltage_regulators_flag)debug("- Checking 3.3V voltage regulators\n");
00196     IF_parse_gpio_byte0(gpio_byte0);
00197     IF_parse_gpio_byte1(gpio_byte1);
00198     testing_voltage_regulators_flag = 0;
00199     //Setup interrupt handler for GPIO interrupts
00200     gpio_interrupt.mode(PullUp);
00201     gpio_interrupt.rise(&IF_handle_gpio_interrupt);
00202     //pc.printf("%c %c",gpio_byte0,gpio_byte1);
00203 
00204     //Secondary GPIO expansion IC is MCP23009
00205     //Address is 0100 111 (0x4E) {defined by AUX_IC_ADDRESS}
00206     //GP0,1,2,3 are outputs for driving infrared emitters and the base LED
00207     //IODIR register wants to be 0xF0 (1=input, 0=output)
00208     data [0] = 0x00;  //Write to IODIR register
00209     data [1] = 0xF0;  //Set GP0-3 as outputs
00210     primary_i2c.write(AUX_IC_ADDRESS,data,2,false);
00211 
00212     if(primary_i2c.write(AUX_IC_ADDRESS,data,2,false) != 0) {
00213         system_warnings += 4;
00214         debug("- WARNING: No I2C acknowledge for aux GPIO IC\n");
00215     }
00216     data [0] = 0x06;  //Write to GPPU register
00217     data [1] = 0x3F;  //Set GP0-3 as active pull-up outputs and P4,P5 as pull-up inputs
00218     primary_i2c.write(AUX_IC_ADDRESS,data,2,false);
00219 
00220     //My interrupt is not so reliable: poll with a 50ms timeout in case interrupts aren't handled
00221     update_timeout.attach_us(&IF_update_gpio_inputs,50000);
00222     //return ret_val;
00223 }
00224 
00225 void IF_read_aux_ic_data()
00226 {
00227     //Read the values of the input pins on the auxilliary GPIO expander
00228     char write_data [1];
00229     char read_data [1];
00230     write_data[0] = 0x09;
00231     primary_i2c.write(AUX_IC_ADDRESS,write_data,1,false);
00232     primary_i2c.read(AUX_IC_ADDRESS,read_data,1,false);
00233     char old_charging_state = status_dc_in;
00234     status_dc_in = 1-((read_data[0] & 0x10) >> 4);
00235     if(status_dc_in!=old_charging_state){
00236         if(status_dc_in == 0)debug("No DC input\n");
00237         else debug("DC input to charge pins\n");
00238     }
00239     //pc.printf("Aux IC Data:%X Charge:%d\n",read_data[0],charge_in);
00240 }
00241 
00242 void IF_parse_gpio_byte0(char byte)
00243 {
00244     gpio_byte0 = byte;
00245     //GPIO byte zero contains the power line traces and the switch states
00246     char current_switch = ((gpio_byte0 & 0xF8) >> 3);
00247     if(switch_set == 1) {
00248         if(current_switch != switch_byte) {
00249             previous_switch_byte = switch_byte;
00250             switch_byte = current_switch;
00251             event++;
00252             switch_event = 1;
00253         }
00254     } else {
00255         switch_byte = current_switch;
00256         switch_set = 1;
00257     }
00258     if(((gpio_byte0 & 0x01)) != power_good_motor_left){
00259         power_good_motor_left = (gpio_byte0 & 0x01);
00260         if(!power_good_motor_left){
00261             if(testing_voltage_regulators_flag || SHOW_VR_WARNINGS)debug("- WARNING: Voltage regulator left motor low\n");    
00262         }
00263         else if(testing_voltage_regulators_flag)debug("- Power good left motor v.reg\n");
00264     } 
00265     if(((gpio_byte0 & 0x02) >> 1) != power_good_motor_right){
00266         power_good_motor_right = (gpio_byte0 & 0x02) >> 1;
00267         if(!power_good_motor_right){
00268             if(testing_voltage_regulators_flag || SHOW_VR_WARNINGS)debug("- WARNING: Voltage regulator right motor low\n");
00269         }
00270         else if(testing_voltage_regulators_flag)debug("- Power good right motor v.reg\n");
00271     } 
00272     if(((gpio_byte0 & 0x04) >> 2) != power_good_infrared){
00273         power_good_infrared = (gpio_byte0 & 0x04) >> 2;
00274         if(!power_good_infrared){
00275             if(testing_voltage_regulators_flag || SHOW_VR_WARNINGS)debug("- WARNING: Voltage regulator infrared low\n");
00276         }
00277         else if(testing_voltage_regulators_flag)debug("- Power good infrared and aux v.reg\n");
00278     } 
00279     if(USE_LED4_FOR_VR_WARNINGS){
00280          mbed_led4 = (!power_good_motor_left || !power_good_motor_right || !power_good_infrared);
00281     }
00282     //Halt the system if settings flag is set and all v-regs are bad [usually this means robot is switched off!]
00283     if(HALT_ON_ALL_VREGS_LOW && !power_good_motor_left && !power_good_motor_right && !power_good_infrared){
00284         debug("- PROGRAM HALTED.  Check that robot is switched on!\n");
00285         while(1){
00286              mbed_led1=1;
00287              mbed_led2=0;
00288              mbed_led3=1;
00289              mbed_led4=0;
00290              wait(0.25); 
00291              mbed_led1=0;
00292              mbed_led2=1;
00293              mbed_led3=0;
00294              mbed_led4=1;
00295              wait(0.25); 
00296         }
00297     }
00298 }
00299 
00300 void IF_parse_gpio_byte1(char byte)
00301 {
00302     gpio_byte1 = byte;
00303     //GPIO byte one contains the wheel encoders and the ID switch
00304     char current_id = ((gpio_byte1 & 0xF0)>> 4);
00305     if(user_id_set == 1) {
00306         if(robot_id != current_id) {
00307             previous_robot_id = robot_id;
00308             robot_id = current_id;
00309             event++;
00310             change_id_event = 1;
00311         }
00312     } else {
00313         robot_id = current_id;
00314         user_id_set = 1;
00315     }
00316     char current_encoder = (gpio_byte1 & 0x0F);
00317     if(wheel_enc_set == 1) {
00318         if(wheel_encoder_byte != current_encoder) {
00319             previous_wheel_encoder_byte = wheel_encoder_byte;
00320             wheel_encoder_byte = current_encoder;
00321             event++;
00322             encoder_event = 1;
00323         }
00324     } else {
00325         wheel_encoder_byte = current_encoder;
00326         wheel_enc_set = 1;
00327     }
00328 }
00329 
00330 void IF_handle_gpio_interrupt()
00331 {
00332     test = 1-test;
00333     if(USE_LED3_FOR_INTERRUPTS) mbed_led3 = test;
00334     IF_update_gpio_inputs();
00335 }
00336 
00337 char IF_is_switch_pressed()
00338 {
00339     //Read data
00340     char data[1];
00341     char command[1] = {0}; //Command to read from input port 0
00342     primary_i2c.write(GPIO_IC_ADDRESS,command,1,false);
00343     primary_i2c.read(GPIO_IC_ADDRESS,data,1,false);
00344     return (data[0] & 0x80);  //Returns a 1 if the center button is being pushed
00345 }
00346 
00347 
00348 char IF_get_switch_state()
00349 {
00350     //Read data
00351     char data[1];
00352     char command[1] = {0}; //Command to read from input port 0
00353     primary_i2c.write(GPIO_IC_ADDRESS,command,1,false);
00354     primary_i2c.read(GPIO_IC_ADDRESS,data,1,false);
00355     return (data[0] & 0xF8) >> 3;  //Returns the current switch state
00356 }
00357 
00358 void IF_update_gpio_inputs()
00359 {
00360     update_timeout.detach();
00361     //Read data
00362     char data[2];
00363     char command[1] = {0}; //Command to read from input port 0
00364     primary_i2c.write(GPIO_IC_ADDRESS,command,1,false);
00365     primary_i2c.read(GPIO_IC_ADDRESS,data,2,false);
00366     if(data[0]!=gpio_byte0) {
00367         IF_parse_gpio_byte0(data[0]);
00368     }
00369     if(data[1]!=gpio_byte1) {
00370         IF_parse_gpio_byte1(data[1]);
00371     }
00372     update_timeout.attach_us(&IF_update_gpio_inputs,50000);
00373 }
00374 
00375 
00376 void IF_write_to_led_ic(char byte_0, char byte_1)
00377 {
00378     //Set LEDs
00379     char data[3];
00380     data [0] = 0x02;    //Write to output port
00381     data [1] = byte_0;
00382     data [2] = byte_1;
00383     primary_i2c.write(LED_IC_ADDRESS,data,3,false);
00384 }
00385 
00386 
00387 void IF_setup_temperature_sensor()
00388 {
00389     char data[3];
00390     data[0] = 0x04; //Set critical temp limit
00391     data[1] = TEMPERATURE_CRITICAL_HI;
00392     data[2] = TEMPEARTURE_CRITICAL_LO;
00393     primary_i2c.write(TEMPERATURE_ADDRESS,data,3,false);
00394     data[0] = 0x02; //Set high temp limit
00395     data[1] = TEMPERATURE_HIGH_HI;
00396     data[2] = TEMPEARTURE_HIGH_LO;
00397     primary_i2c.write(TEMPERATURE_ADDRESS,data,3,false);
00398     data[0] = 0x03; //Set low temp limit
00399     data[1] = TEMPERATURE_LOW_HI;
00400     data[2] = TEMPEARTURE_LOW_LO;
00401     primary_i2c.write(TEMPERATURE_ADDRESS,data,3,false);
00402 }
00403 
00404 float IF_read_from_temperature_sensor()
00405 {
00406     char command[1] = {0x05};  //Write to Ta Register
00407     char data[3];
00408     signed int temp;
00409     float temperature;
00410     primary_i2c.write(TEMPERATURE_ADDRESS,command,1,false);
00411     primary_i2c.read(TEMPERATURE_ADDRESS,data,2,false);
00412 
00413     //Convert the temperature data
00414     //First Check flag bits
00415     char UpperByte = data[0];
00416     char LowerByte = data[1];
00417     if ((UpperByte & 0x80) == 0x80) {
00418         debug("- WARNING: Temperature sensor reports critical temperature\n");
00419     }
00420     if ((UpperByte & 0x40) == 0x40) {
00421         debug("- WARNING: Temperature sensor reports above upper limit\n");
00422     }
00423     if ((UpperByte & 0x20) == 0x20) {
00424         debug("- WARNING: Temperature sensor reports below lower limit\n");
00425     }
00426     UpperByte = UpperByte & 0x1F;       //Clear flag bits
00427     if ((UpperByte & 0x10) == 0x10) {
00428         UpperByte = UpperByte & 0x0F;   //Clear SIGN
00429         temp = (UpperByte * 256) + LowerByte;
00430         temperature = - (temp / 16.0f);
00431     } else   {
00432         temp = (UpperByte * 256) + LowerByte;
00433         temperature = (temp / 16.0f);
00434     }
00435     return temperature;
00436 }