/* Analog and Digital Input and Output Server for MATLAB */ /* Giampiero Campa, Copyright 2009 The MathWorks, Inc */ /* This file is meant to be used with the MATLAB arduino IO package, however, it can be used from the IDE environment (or any other serial terminal) by typing commands like: 0e0 : assigns digital pin #4 (e) as input 0f1 : assigns digital pin #5 (f) as output 0n1 : assigns digital pin #13 (n) as output 1c : reads digital pin #2 (c) 1e : reads digital pin #4 (e) 2n0 : sets digital pin #13 (n) low 2n1 : sets digital pin #13 (n) high 2f1 : sets digital pin #5 (f) high 2f0 : sets digital pin #5 (f) low 4j2 : sets digital pin #9 (j) to 50=ascii(2) over 255 4jz : sets digital pin #9 (j) to 122=ascii(z) over 255 3a : reads analog pin #0 (a) 3f : reads analog pin #5 (f) R0 : sets analog reference to DEFAULT R1 : sets analog reference to INTERNAL R2 : sets analog reference to EXTERNAL 99 : returns script type (1 basic, 2 motor, 3 general) */ /* define internal for the MEGA as 1.1V (as as for the 328) */ #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) #define INTERNAL INTERNAL1V1 #endif void setup() { /* Make sure all pins are put in high impedence state and that their registers are set as low before doing anything. This puts the board in a known (and harmless) state */ int i; for (i=0;i<20;i++) { pinMode(i,INPUT); digitalWrite(i,0); } /* initialize serial */ Serial.begin(115200); } void loop() { /* variables declaration and initialization */ static int s = -1; /* state */ static int pin = 13; /* generic pin number */ int val = 0; /* generic value read from serial */ int agv = 0; /* generic analog value */ int dgv = 0; /* generic digital value */ /* The following instruction constantly checks if anything is available on the serial port. Nothing gets executed in the loop if nothing is available to be read, but as soon as anything becomes available, then the part coded after the if statement (that is the real stuff) gets executed */ if (Serial.available() >0) { /* whatever is available from the serial is read here */ val = Serial.read(); /* This part basically implements a state machine that reads the serial port and makes just one transition to a new state, depending on both the previous state and the command that is read from the serial port. Some commands need additional inputs from the serial port, so they need 2 or 3 state transitions (each one happening as soon as anything new is available from the serial port) to be fully executed. After a command is fully executed the state returns to its initial value s=-1 */ switch (s) { /* s=-1 means NOTHING RECEIVED YET ******************* */ case -1: /* calculate next state */ if (val>47 && val<90) { /* the first received value indicates the mode 49 is ascii for 1, ... 90 is ascii for Z s=0 is change-pin mode s=10 is DI; s=20 is DO; s=30 is AI; s=40 is AO; s=90 is query script type (1 basic, 2 motor) s=340 is change analog reference */ s=10*(val-48); } /* the following statements are needed to handle unexpected first values coming from the serial (if the value is unrecognized then it defaults to s=-1) */ if ((s>40 && s<90) || (s>90 && s!=340)) { s=-1; } /* the break statements gets out of the switch-case, so /* we go back to line 97 and wait for new serial data */ break; /* s=-1 (initial state) taken care of */ /* s=0 or 1 means CHANGE PIN MODE */ case 0: /* the second received value indicates the pin from abs('c')=99, pin 2, to abs('t')=116, pin 19 */ if (val>98 && val<117) { pin=val-97; /* calculate pin */ s=1; /* next we will need to get 0 or 1 from serial */ } else { s=-1; /* if value is not a pin then return to -1 */ } break; /* s=0 taken care of */ case 1: /* the third received value indicates the value 0 or 1 */ if (val>47 && val<50) { /* set pin mode */ if (val==48) { pinMode(pin,INPUT); } else { pinMode(pin,OUTPUT); } } s=-1; /* we are done with CHANGE PIN so go to -1 */ break; /* s=1 taken care of */ /* s=10 means DIGITAL INPUT ************************** */ case 10: /* the second received value indicates the pin from abs('c')=99, pin 2, to abs('t')=116, pin 19 */ if (val>98 && val<117) { pin=val-97; /* calculate pin */ dgv=digitalRead(pin); /* perform Digital Input */ Serial.println(dgv); /* send value via serial */ } s=-1; /* we are done with DI so next state is -1 */ break; /* s=10 taken care of */ /* s=20 or 21 means DIGITAL OUTPUT ******************* */ case 20: /* the second received value indicates the pin from abs('c')=99, pin 2, to abs('t')=116, pin 19 */ if (val>98 && val<117) { pin=val-97; /* calculate pin */ s=21; /* next we will need to get 0 or 1 from serial */ } else { s=-1; /* if value is not a pin then return to -1 */ } break; /* s=20 taken care of */ case 21: /* the third received value indicates the value 0 or 1 */ if (val>47 && val<50) { dgv=val-48; /* calculate value */ digitalWrite(pin,dgv); /* perform Digital Output */ } s=-1; /* we are done with DO so next state is -1 */ break; /* s=21 taken care of */ /* s=30 means ANALOG INPUT *************************** */ case 30: /* the second received value indicates the pin from abs('a')=97, pin 0, to abs('f')=102, pin 6, note that these are the digital pins from 14 to 19 located in the lower right part of the board */ if (val>96 && val<103) { pin=val-97; /* calculate pin */ agv=analogRead(pin); /* perform Analog Input */ Serial.println(agv); /* send value via serial */ } s=-1; /* we are done with AI so next state is -1 */ break; /* s=30 taken care of */ /* s=40 or 41 means ANALOG OUTPUT ******************** */ case 40: /* the second received value indicates the pin from abs('c')=99, pin 2, to abs('t')=116, pin 19 */ if (val>98 && val<117) { pin=val-97; /* calculate pin */ s=41; /* next we will need to get value from serial */ } else { s=-1; /* if value is not a pin then return to -1 */ } break; /* s=40 taken care of */ case 41: /* the third received value indicates the analog value */ analogWrite(pin,val); /* perform Analog Output */ s=-1; /* we are done with AO so next state is -1 */ break; /* s=41 taken care of */ /* s=90 means Query Script Type (1 basic, 2 motor) */ case 90: if (val==57) { /* if string sent is 99 send script type via serial */ Serial.println(1); } s=-1; /* we are done with this so next state is -1 */ break; /* s=90 taken care of */ /* s=340 or 341 means ANALOG REFERENCE *************** */ case 340: /* the second received value indicates the reference, which is encoded as is 0,1,2 for DEFAULT, INTERNAL and EXTERNAL, respectively */ switch (val) { case 48: analogReference(DEFAULT); break; case 49: analogReference(INTERNAL); break; case 50: analogReference(EXTERNAL); break; default: /* unrecognized, no action */ break; } s=-1; /* we are done with this so next state is -1 */ break; /* s=341 taken care of */ /* ******* UNRECOGNIZED STATE, go back to s=-1 ******* */ default: /* we should never get here but if we do it means we are in an unexpected state so whatever is the second received value we get out of here and back to s=-1 */ s=-1; /* go back to the initial state, break unneeded */ } /* end switch on state s */ } /* end if serial available */ } /* end loop statement */