Quasar Web Console Control Quasar Basic or Arduino Uno from the browser, over USB or Bluetooth (HC-05)

The sketch

The sketch listens to commands both on USB and on the HC-05, at 9600 baud. It works on Quasar Basic and on Arduino Uno.

/*
  Quasar Console 2.0 - Starlyware
  https://www.starlyware.com/products/quasar/console

  Lets the Quasar web console control the board over USB or over a
  Bluetooth HC-05 module. Works on Quasar Basic and on Arduino Uno
  (any ATmega328P board at 16 MHz). In the Arduino IDE choose "Arduino Uno".

  HC-05 wiring:
    HC-05 VCC -> 5V
    HC-05 GND -> GND
    HC-05 TXD -> D2 (board RX for Bluetooth)
    HC-05 RXD <- D3 through a voltage divider (1 kOhm from D3, 2 kOhm to GND):
                 the HC-05 RX pin works at 3.3 V.

  Commands (one per line, upper or lower case), pins 4-13:
    PING                 -> PONG QUASAR
    HELP                 -> list of commands
    ON 13 / OFF 13       -> digital output HIGH or LOW
    TOGGLE 13            -> invert a digital output
    PWM 9 128            -> PWM 0-255 on pins 5, 6, 9, 10, 11
    MODE 7 IN            -> pin mode: OUT, IN or PULLUP
    SERVO 9 90           -> servo angle 0-180 (SERVO 9 OFF to release it)
    READ A0 / READ D7    -> read an analog input (0-1023) or a digital pin
    STREAM 50 A0 A1      -> send the analog inputs every 50 ms (20-5000)
    STREAM OFF           -> stop the stream
    STATUS               -> state of pins 4-13 and A0-A5

  Answers use KEY=VALUE pairs: D = digital output, P = PWM, I = input,
  U = input with pull-up, S = servo angle, A = analog input, T = time in ms.
  Digital inputs report their changes automatically.

  Note: while a servo is attached, the Servo library uses Timer1 and
  PWM on pins 9 and 10 stops working.

  Serial speed: 9600 baud on both USB and Bluetooth (HC-05 default).
  If your HC-05 is configured at 38400, change BT_BAUD below.
*/

#include <SoftwareSerial.h>
#include <Servo.h>

const uint8_t BT_RX_PIN = 2;   // connected to HC-05 TXD
const uint8_t BT_TX_PIN = 3;   // connected to HC-05 RXD (through the divider)
const long USB_BAUD = 9600;
const long BT_BAUD = 9600;

const uint8_t FIRST_PIN = 4;
const uint8_t LAST_PIN = 13;
const uint8_t LINE_MAX = 40;
const uint8_t MAX_ARGS = 8;

enum QMode : uint8_t { M_OUT, M_PWM, M_IN, M_PULLUP, M_SERVO };

SoftwareSerial bt(BT_RX_PIN, BT_TX_PIN);
Servo servos[LAST_PIN - FIRST_PIN + 1];   // one per pin 4-13 (10 of the 12 available)

uint8_t pinModeOf[LAST_PIN + 1];
int pinValue[LAST_PIN + 1];                // output value, PWM value, input level or servo angle
Stream *lastOut = &Serial;                 // where spontaneous messages go

uint8_t streamMask = 0;                    // bit n = stream analog input An
unsigned long streamInterval = 0;
unsigned long lastStream = 0;
unsigned long lastInputPoll = 0;

char usbLine[LINE_MAX];
uint8_t usbLen = 0;
char btLine[LINE_MAX];
uint8_t btLen = 0;

bool isPwmPin(int p) {
  return p == 5 || p == 6 || p == 9 || p == 10 || p == 11;
}

// Accepts "13" or "D13". Returns -1 if not a usable pin.
int parseDigital(const char *t) {
  if (!t) return -1;
  if (*t == 'D') t++;
  if (*t < '0' || *t > '9') return -1;
  int p = atoi(t);
  return (p >= FIRST_PIN && p <= LAST_PIN) ? p : -1;
}

// Accepts "A0".."A5". Returns -1 if not valid.
int parseAnalog(const char *t) {
  if (!t || t[0] != 'A' || t[1] < '0' || t[1] > '5' || t[2] != 0) return -1;
  return t[1] - '0';
}

char modeLetter(uint8_t m) {
  switch (m) {
    case M_PWM: return 'P';
    case M_IN: return 'I';
    case M_PULLUP: return 'U';
    case M_SERVO: return 'S';
    default: return 'D';
  }
}

void printPin(Stream &out, int p) {
  out.print(modeLetter(pinModeOf[p]));
  out.print(p);
  out.print('=');
  out.print(pinValue[p]);
}

void releaseServo(int p) {
  if (pinModeOf[p] == M_SERVO) servos[p - FIRST_PIN].detach();
}

void makeOutput(int p) {
  releaseServo(p);
  if (pinModeOf[p] == M_IN || pinModeOf[p] == M_PULLUP || pinModeOf[p] == M_SERVO) {
    pinMode(p, OUTPUT);
    digitalWrite(p, LOW);
    pinValue[p] = 0;
  }
  pinModeOf[p] = M_OUT;
}

void printStatus(Stream &out) {
  for (int p = FIRST_PIN; p <= LAST_PIN; p++) {
    printPin(out, p);
    out.print(' ');
  }
  for (int a = 0; a <= 5; a++) {
    out.print('A'); out.print(a); out.print('='); out.print(analogRead(A0 + a));
    if (a < 5) out.print(' ');
  }
  out.println();
}

void handle(char *line, Stream &out) {
  lastOut = &out;
  for (char *c = line; *c; c++) *c = toupper(*c);
  char *arg[MAX_ARGS];
  uint8_t n = 0;
  for (char *t = strtok(line, " "); t && n < MAX_ARGS; t = strtok(NULL, " ")) arg[n++] = t;
  if (n == 0) return;
  const char *cmd = arg[0];

  if (!strcmp(cmd, "PING")) {
    out.println(F("PONG QUASAR"));

  } else if (!strcmp(cmd, "HELP")) {
    out.println(F("OK PING HELP ON OFF TOGGLE PWM MODE SERVO READ STREAM STATUS"));

  } else if (!strcmp(cmd, "STATUS")) {
    out.print(F("STATUS "));
    printStatus(out);

  } else if (!strcmp(cmd, "ON") || !strcmp(cmd, "OFF") || !strcmp(cmd, "TOGGLE")) {
    int p = parseDigital(n > 1 ? arg[1] : NULL);
    if (p < 0) { out.println(F("ERR PIN 4-13")); return; }
    bool wasOn = pinModeOf[p] == M_OUT || pinModeOf[p] == M_PWM ? pinValue[p] > 0 : false;
    makeOutput(p);
    int v = !strcmp(cmd, "ON") ? 1 : !strcmp(cmd, "OFF") ? 0 : (wasOn ? 0 : 1);
    digitalWrite(p, v ? HIGH : LOW);
    pinValue[p] = v;
    out.print(F("OK ")); printPin(out, p); out.println();

  } else if (!strcmp(cmd, "PWM")) {
    int p = parseDigital(n > 1 ? arg[1] : NULL);
    if (p < 0 || !isPwmPin(p)) { out.println(F("ERR PWM PIN 5 6 9 10 11")); return; }
    if (n < 3) { out.println(F("ERR VALUE 0-255")); return; }
    makeOutput(p);
    int v = constrain(atoi(arg[2]), 0, 255);
    analogWrite(p, v);
    pinValue[p] = v;
    pinModeOf[p] = M_PWM;
    out.print(F("OK ")); printPin(out, p); out.println();

  } else if (!strcmp(cmd, "MODE")) {
    int p = parseDigital(n > 1 ? arg[1] : NULL);
    if (p < 0 || n < 3) { out.println(F("ERR MODE PIN OUT|IN|PULLUP")); return; }
    if (!strcmp(arg[2], "OUT")) {
      makeOutput(p);
      digitalWrite(p, LOW);
      pinValue[p] = 0;
    } else if (!strcmp(arg[2], "IN") || !strcmp(arg[2], "PULLUP")) {
      releaseServo(p);
      bool pullup = !strcmp(arg[2], "PULLUP");
      pinMode(p, pullup ? INPUT_PULLUP : INPUT);
      pinModeOf[p] = pullup ? M_PULLUP : M_IN;
      pinValue[p] = digitalRead(p);
    } else {
      out.println(F("ERR MODE OUT|IN|PULLUP")); return;
    }
    out.print(F("OK ")); printPin(out, p); out.println();

  } else if (!strcmp(cmd, "SERVO")) {
    int p = parseDigital(n > 1 ? arg[1] : NULL);
    if (p < 0 || n < 3) { out.println(F("ERR SERVO PIN 0-180|OFF")); return; }
    if (!strcmp(arg[2], "OFF")) {
      makeOutput(p);
      out.print(F("OK ")); printPin(out, p); out.println();
      return;
    }
    int angle = constrain(atoi(arg[2]), 0, 180);
    if (pinModeOf[p] != M_SERVO) {
      servos[p - FIRST_PIN].attach(p);
      pinModeOf[p] = M_SERVO;
    }
    servos[p - FIRST_PIN].write(angle);
    pinValue[p] = angle;
    out.print(F("OK ")); printPin(out, p); out.println();

  } else if (!strcmp(cmd, "READ")) {
    int a = parseAnalog(n > 1 ? arg[1] : NULL);
    if (a >= 0) {
      out.print('A'); out.print(a); out.print('='); out.println(analogRead(A0 + a));
      return;
    }
    int p = parseDigital(n > 1 ? arg[1] : NULL);
    if (p < 0) { out.println(F("ERR READ A0-A5|D4-D13")); return; }
    if (pinModeOf[p] == M_IN || pinModeOf[p] == M_PULLUP) pinValue[p] = digitalRead(p);
    printPin(out, p); out.println();

  } else if (!strcmp(cmd, "STREAM")) {
    if (n > 1 && !strcmp(arg[1], "OFF")) {
      streamMask = 0;
      out.println(F("OK STREAM OFF"));
      return;
    }
    long ms = n > 1 ? atol(arg[1]) : 0;
    uint8_t mask = 0;
    for (uint8_t i = 2; i < n; i++) {
      int a = parseAnalog(arg[i]);
      if (a >= 0) mask |= (1 << a);
    }
    if (ms < 20 || ms > 5000 || mask == 0) { out.println(F("ERR STREAM 20-5000 A0..A5")); return; }
    streamInterval = ms;
    streamMask = mask;
    lastStream = 0;
    out.println(F("OK STREAM ON"));

  } else {
    out.println(F("ERR UNKNOWN COMMAND"));
  }
}

// Collects characters until a newline, then runs the command.
void readLine(Stream &in, char *buf, uint8_t &len) {
  while (in.available()) {
    char c = in.read();
    if (c == '\r') continue;
    if (c == '\n') {
      buf[len] = 0;
      if (len > 0) handle(buf, in);
      len = 0;
    } else if (len < LINE_MAX - 1) {
      buf[len++] = c;
    }
  }
}

// Reports the inputs that changed since the last check.
void pollInputs() {
  for (int p = FIRST_PIN; p <= LAST_PIN; p++) {
    if (pinModeOf[p] != M_IN && pinModeOf[p] != M_PULLUP) continue;
    int v = digitalRead(p);
    if (v != pinValue[p]) {
      pinValue[p] = v;
      printPin(*lastOut, p);
      lastOut->println();
    }
  }
}

void sendStream() {
  lastOut->print(F("STREAM T="));
  lastOut->print(millis());
  for (uint8_t a = 0; a <= 5; a++) {
    if (!(streamMask & (1 << a))) continue;
    lastOut->print(F(" A")); lastOut->print(a); lastOut->print('=');
    lastOut->print(analogRead(A0 + a));
  }
  lastOut->println();
}

void setup() {
  for (int p = FIRST_PIN; p <= LAST_PIN; p++) {
    pinMode(p, OUTPUT);
    digitalWrite(p, LOW);
    pinModeOf[p] = M_OUT;
    pinValue[p] = 0;
  }
  Serial.begin(USB_BAUD);
  bt.begin(BT_BAUD);
  Serial.println(F("READY QUASAR CONSOLE 2"));
  bt.println(F("READY QUASAR CONSOLE 2"));
}

void loop() {
  readLine(Serial, usbLine, usbLen);
  readLine(bt, btLine, btLen);

  unsigned long now = millis();
  if (now - lastInputPoll >= 20) {
    lastInputPoll = now;
    pollInputs();
  }
  if (streamMask && now - lastStream >= streamInterval) {
    lastStream = now;
    sendStream();
  }
}