Mutantc_v3

Made by rahmanshaber / 3D Printing / Displays / Productivity / IoT

About the project

A Raspberry-pi handheld platform with a physical keyboard, Display and Expansion header for add-on baords (Like Ardinuo Shield).

Project info

Difficulty: Moderate

Platforms: Arduino, Raspberry Pi, Linux

Estimated time: 4 hours

License: MIT license (MIT)

Items used in this project

Hardware components

	Raspberry Pi 3 Model B	x 1
	3.5 inch gpio LCD	x 1
	SparkFun Pro Micro 5v/16Mhz	x 1
	LI-ION #18650 2.6AH Cell W/PCB	x 1

Software apps and online services

Arduino

Hand tools and fabrication machines

	3D printer	x 1
	PCB	x 1

Story

A Raspberry-pi handheld platform with a physical keyboard, Display and Expansion header for add-on baords (Like Ardinuo Shield).

Here we will dicusses what you need to build one. This device is very easy to make, you don't need lots of tools and parts.

No codding skill is needed. just basic stuff like uplaod a code to Ardinuo, little skill in Linux CMD line to install the driver. Little soldering skill that's all.

mutantC_V3 is successor of mutantC_V2 and with more features.

This improves big parts and brings new improvements like .

Have RTC & buzzer.
Supports all the v2 Add-ons, see all from HERE.
A track point to have mouse support with left, right buttons.
Gyro support using MPU6050 module & pressure, temp and humidity support using BME280 module.
Able to turn of modules, Display, Add-ons using keyboard button.
Full poweroff using OS and keyboard key.
12 pin docking port beside Pi USB ports with UART, I2C, Charging and GPIO.
Able to read battery voltage using Pro Micro.
2 LED's connected to Pro Micro with PWM support and 1 connected Pi.
Move the stema/Qt I2c connector bottom so it is acessible from outside.
18650 battery with charge and discharge protraction .
Improvements to Stop position for sliding mechanism.
5 row, 56 key customizable keyboard .
New 2 shoulder button for navigation.
Reduce keyboard power usage .
Have Adafruit STEMMA QT and SparkFun qwiic connector.

See the parts list for updated list of parts.

For more updates see the Gitlab project page.

Schematics, diagrams and documents

thumbstick_pcb

main_pcb

display_pcb

CAD, enclosures and custom parts

rigth_part_pi3

display_bottom

body_bottom

display_top_4.0_inch

display_top_3.5_inch

rigth_part_pi4

body_top

Code

Firmware

Use arduino to flash this code to Pro micro

// firmware V3.4
// mutantC v3

#include <Keypad.h>
/*
 * Depending on which i2c expander is used different i2c keypad library has to be used.
 *
 * For PCF8575  inlucde <Keypad_I2C.h>
 * For PCA9555D include <Keypad_I2Ca.h>
 */
#include <Keypad_I2C.h>
#include <HID-Project.h>
#include <Wire.h>

#define FIRMWARE_VERSION 3410

#define LED_BODY        6
#define LED_DISPLAY     10
#define POWER_MAIN      15
#define POWER_OFF_BTN   A0
#define BATTERY_VOLTAGE A9
#define BUZZER          A2

#define POWER_LCD     14
#define POWER_EXP     16
#define POWER_SENSORS 0

#define PI_POWEROFF_SIGNAL A3

#define DOCK_PIN 1

/* Thumbstick buttons */
#define THUMB_UP     7
#define THUMB_DOWN   A1
#define THUMB_LEFT   5
#define THUMB_RIGHT  8
#define THUMB_MIDDLE 4

// Switch Stats
static bool keymapState = 0;

// For Keypad
#define KBD_ROWS 5
#define KBD_COLS 11

#define KEYS_TILDE      KEY_TILDE|MOD_LEFT_SHIFT       /* ~ */
#define KEYS_EXCL       KEY_1|MOD_LEFT_SHIFT           /* ! */
#define KEYS_AT         KEY_2|MOD_LEFT_SHIFT           /* @ */
#define KEYS_HASH       KEY_3|MOD_LEFT_SHIFT           /* # */
#define KEYS_DOLLAR     KEY_4|MOD_LEFT_SHIFT           /* $ */
#define KEYS_PERCENT    KEY_5|MOD_LEFT_SHIFT           /* % */
#define KEYS_CARET      KEY_6|MOD_LEFT_SHIFT           /* ^ */
#define KEYS_AMP        KEY_7|MOD_LEFT_SHIFT           /* & */
#define KEYS_ASTERISK   KEY_8|MOD_LEFT_SHIFT           /* * */
#define KEYS_LRBRACKET  KEY_9|MOD_LEFT_SHIFT           /* ( */
#define KEYS_RRBRACKET  KEY_0|MOD_LEFT_SHIFT           /* ) */
#define KEYS_UNDERSCORE KEY_MINUS|MOD_LEFT_SHIFT       /* _ */
#define KEYS_PLUS       KEY_EQUAL|MOD_LEFT_SHIFT       /* + */
#define KEYS_LCBRACKET  KEY_LEFT_BRACE|MOD_LEFT_SHIFT  /* { */
#define KEYS_RCBRACKET  KEY_RIGHT_BRACE|MOD_LEFT_SHIFT /* } */
#define KEYS_VBAR       KEY_BACKSLASH|MOD_LEFT_SHIFT   /* \ */
#define KEYS_COLON      KEY_SEMICOLON|MOD_LEFT_SHIFT   /* : */
#define KEYS_DQUOTE     KEY_QUOTE|MOD_LEFT_SHIFT       /* " */
#define KEYS_LABRACKET  KEY_COMMA|MOD_LEFT_SHIFT       /* < */
#define KEYS_RABRACKET  KEY_PERIOD|MOD_LEFT_SHIFT      /* > */
#define KEYS_QMARK      KEY_SLASH|MOD_LEFT_SHIFT       /* ? */

#define KMAP_SWITCH           0xffff
#define LCD_SWITCH            0xfffe
#define KMOUSE_MIDDLE         0xffef
#define KMOUSE_RIGHT          0xfeff

static uint16_t keymapSymbols[] = {
    KMOUSE_RIGHT,   LCD_SWITCH,              'E',             'E',             'E',             'E',            'E',            'E',            'E',    KMAP_SWITCH,  KMOUSE_MIDDLE,
        KEY_ESC,    KEYS_EXCL,           KEYS_AT,       KEYS_HASH,      KEYS_DOLLAR,    KEYS_PERCENT,     KEYS_CARET,       KEYS_AMP, KEYS_LRBRACKET, KEYS_RRBRACKET,      KEY_LEFT,
        KEY_TAB,    KEYS_VBAR,            KEY_UP, KEYS_UNDERSCORE,       KEYS_TILDE,      KEYS_COLON,  KEY_SEMICOLON,    KEYS_DQUOTE,      KEY_QUOTE,      KEY_TILDE,     KEY_RIGHT,
  KEY_CAPS_LOCK,     KEY_LEFT,          KEY_DOWN,       KEY_RIGHT,   KEY_LEFT_BRACE, KEY_RIGHT_BRACE, KEYS_LCBRACKET, KEYS_RCBRACKET, KEYS_LABRACKET, KEYS_RABRACKET, KEY_BACKSPACE,
  KEY_LEFT_CTRL, KEY_LEFT_GUI,         KEYS_PLUS,       KEY_MINUS,        KEY_SLASH,   KEYS_ASTERISK,      KEY_EQUAL,      KEY_COMMA,     KEY_PERIOD,     KEYS_QMARK,     KEY_ENTER
};

static uint16_t keymapAlpha[] = {
   KMOUSE_RIGHT,   LCD_SWITCH,   KEY_PRINTSCREEN, KEY_INSERT, KEY_DELETE, KEY_HOME, KEY_END, KEY_PAGE_UP, KEY_PAGE_DOWN, KMAP_SWITCH,   KMOUSE_MIDDLE,
          KEY_1,        KEY_2,             KEY_3,      KEY_4,      KEY_5,    KEY_6,   KEY_7,       KEY_8,         KEY_9,       KEY_0,        KEY_LEFT,
          KEY_Q,        KEY_W,             KEY_E,      KEY_R,      KEY_T,    KEY_Y,   KEY_U,       KEY_I,         KEY_O,       KEY_P,       KEY_RIGHT,
  KEY_CAPS_LOCK,        KEY_A,             KEY_S,      KEY_D,      KEY_F,    KEY_G,   KEY_H,       KEY_J,         KEY_K,       KEY_L,   KEY_BACKSPACE,
  KEY_LEFT_CTRL, KEY_LEFT_GUI,             KEY_Z,      KEY_X,      KEY_C,    KEY_V,   KEY_B,       KEY_N,         KEY_M,   KEY_SPACE,       KEY_ENTER
};

static char dummyKeypad[KBD_ROWS][KBD_COLS] = {
  { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10},
  {11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21},
  {22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32},
  {33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43},
  {44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54}
};

/*
 * Pin mappings on the I2C 16bit expander for the matrix keyboard.
 */
static byte kbd_row_pins[KBD_ROWS] = {11, 15, 2, 4, 5};
static byte kbd_col_pins[KBD_COLS] = {6, 9, 8, 7, 10, 12, 13, 14, 3, 1, 0};

/*
 * Depending on which I2C expander is used different I2C keypad library has to be used.
 *
 * For PCF8575  the object is called Keypad_I2C
 * For PCA9555D the object is called Keypad_I2Ca
 *
 * The bus address is the same in both cases.
 */
#define I2C_EXP_ADDR 0x20

Keypad_I2C Dummy(makeKeymap(dummyKeypad), kbd_row_pins, kbd_col_pins, KBD_ROWS, KBD_COLS, I2C_EXP_ADDR, 2);

/*
 * Temperature sensor offset should be accordingly to the datasheet between -10 and +10.
 *
 * To callibrate the offset do following:
 *
 * - Let the device sit down powered off at a room temperature for 20 minutes
 * - Turn it on, read temperature using mutantctl
 * - Adjust this constant so that the result matches room temp
 */
#define TEMP_OFFSET -7
/* Temperature in Kelvins when to power off */
static uint16_t temp_thresh = 323;
/* Last temperature measured */
static uint16_t last_temp;

/* Voltage 5V = 10bit, set to ~2750mV */
static uint16_t bat_threshold = 563;
static uint16_t bat_voltage;

void setup(void)
{
  /*  Turn on the FET that powers on the board and RPI first */
  pinMode(POWER_MAIN, OUTPUT);
  digitalWrite(POWER_MAIN, HIGH);

  /* Slow down CPU gets the arduino power consumption to 16mA */
  noInterrupts();
  CLKPR = 0x80;  // enable change of the clock prescaler
  CLKPR = 0x03;  // divide frequency by 8
  interrupts();

  /* Set up ADC MUX to temperature sensor at start */
  adc_select_temp();

  Wire.begin();
  /*
   * The I2C clock depends on the CPU clock so if we slow down CPU we have to adjust
   * the timings. Normally TWBR is set to 72 for 16Mhz CPU clock for 100kHz I2C clock,
   * we set it to 0 which yields 125kHz on 2Mhz CPU clock (since we set prescaler to 8)
   * which is good enough for us.
   */
  TWBR=0;

  Serial.begin(9600);

  pinMode(LED_BODY, OUTPUT);
  pinMode(LED_DISPLAY, OUTPUT);
  pinMode(POWER_OFF_BTN, INPUT_PULLUP);
  pinMode(POWER_EXP, OUTPUT);
  pinMode(POWER_LCD, OUTPUT);
  pinMode(POWER_SENSORS, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(BATTERY_VOLTAGE, INPUT);
  pinMode(PI_POWEROFF_SIGNAL, INPUT);
  pinMode(THUMB_UP, INPUT_PULLUP);
  pinMode(THUMB_DOWN, INPUT_PULLUP);
  pinMode(THUMB_LEFT, INPUT_PULLUP);
  pinMode(THUMB_RIGHT, INPUT_PULLUP);
  pinMode(THUMB_MIDDLE, INPUT_PULLUP);

  digitalWrite(POWER_EXP, HIGH);
  digitalWrite(POWER_LCD, LOW);
  digitalWrite(POWER_SENSORS, HIGH);
  digitalWrite(BUZZER, LOW);

  Mouse.begin();
  Dummy.begin( );

  /* Compensate for the slow CPU */
  Dummy.setHoldTime(1);
  Dummy.setDebounceTime(0);
  Dummy.addEventListener(keypadEvent);

  /* Enable 1ms timer interrupts */
  OCR0A = 0xAF;
  TIMSK0 |= 1<<OCIE0A;
}

static void notify(void)
{
  start_buzzer(10);
  start_led();
}

static void poweroff(void)
{
  uint8_t i;

  notify();

  /* Ask RPi to powerdown */
  Keyboard.write(CONSUMER_POWER);

  /* Wait for RPi to halt OS, about 16 seconds */
  for (i = 0; i < 20; i++) {
    if (digitalRead(PI_POWEROFF_SIGNAL))
      break;

    digitalWrite(LED_DISPLAY, HIGH);
    delay(25);

    if (digitalRead(PI_POWEROFF_SIGNAL))
      break;

    digitalWrite(LED_DISPLAY, LOW);
    delay(25);
  }

  /* And finally turn off the power */
  digitalWrite(POWER_MAIN, LOW);
}

static uint8_t exp_board_power_get(void)
{
  return !digitalRead(POWER_EXP);
}

static void exp_board_power_set(uint8_t val)
{
  if (val)
    digitalWrite(POWER_EXP, LOW);
  else
    digitalWrite(POWER_EXP, HIGH);
}

static uint8_t sensors_power_get(void)
{
  return !digitalRead(POWER_SENSORS);
}

static void sensors_power_set(uint8_t val)
{
  if (val)
    digitalWrite(POWER_SENSORS, LOW);
  else
    digitalWrite(POWER_SENSORS, HIGH);
}

static void lcd_power_toggle(void)
{
  if (digitalRead(POWER_LCD))
    digitalWrite(POWER_LCD, LOW);
  else
    digitalWrite(POWER_LCD, HIGH);
}

static void lcd_power_set(uint8_t val)
{
  if (val)
    digitalWrite(POWER_LCD, LOW);
  else
    digitalWrite(POWER_LCD, HIGH);
}

static uint8_t lcd_power_get(void)
{
  return !digitalRead(POWER_LCD);
}

static void adc_start(void)
{
  ADCSRA |= 1<<ADSC;
}

static void adc_wait(void)
{
  while (bit_is_set(ADCSRA, ADSC));
}

static void adc_select_temp(void)
{
  /* Set reference to 2.56V and MUX to temp sensor */

  ADMUX = (1<<REFS1) | (1<<REFS0) | (1<<MUX2) | (1<<MUX1) | (1<<MUX0);
  ADCSRB |= 1<<MUX5;
}

static void adc_select_bat(void)
{
  /* External 5V refrence and MUX to ADC9 -> battery voltage */
  ADMUX = (1<<REFS0) | (1<<MUX2);
  ADCSRB |= 1<<MUX5;
}

static inline void read_bat_temp(void)
{
  /* Read temperature first */
  adc_start();
  adc_wait();

  last_temp = ADC + TEMP_OFFSET;

  if (last_temp > temp_thresh)
    poweroff();

  adc_select_bat();
  adc_start();
  adc_wait();

  bat_voltage = ADC;

  if (bat_voltage < bat_threshold)
    poweroff();

  /*
   * The internal temperature sensor needs some time to settle down
   * so we configure the MUX for next measurement here.
   */
   adc_select_temp();
}

/*
 * Simple UART protocol for setting and getting data.
 * The message consists of a few bytes followed by a newline.
 *
 * To setup the serial port on RPi use:
 *
 * stty -F /dev/ttyACM0 9600 raw -clocal -echo icrnl
 *
 * Then you can read results and write commands with:
 *
 * cat /dev/ttyACM0
 * cat > /dev/ttyACM0
 *
 * cmd[0]:
 * ? - get value
 * ! - set value
 *
 * cmd[1]
 * T - internal temperature in Kelvin
 * P - poweroff threshold temperature in Kelvin
 * V - mutant hardware revision
 * B - battery voltage (1024 == 5V)
 * Q - poweroff threshold battery voltage (1024 == 5V)
 * L - display led
 * M - body led
 * F - firmware version
 * Z - buzzer turn on for n ns
 *
 * l - LCD screen power
 * e - expansion board power
 * s - sensors power
 *
 * cmd[2] - cmd[4]
 *  - optional command parameter
 *
 * '\n' - message end
 */

static void write_u16_res(char type, uint16_t val)
{
  Serial.write(type);
  Serial.print(val);
  Serial.write('\n');
}

static void process_serial(void)
{
  static uint8_t cmd[6];
  static uint8_t lb = 0;;
  int b;

  while ((b = Serial.read()) > 0) {
    cmd[lb] = b;

    if (cmd[lb] == '\n')
      break;

    lb = (lb + 1) % 6;
  }

  if (cmd[lb] != '\n')
    return;

  switch (cmd[0]) {
  case '?':
    switch (cmd[1]) {
    case 'T':
      write_u16_res('T', last_temp);
    break;
    case 'P':
      write_u16_res('P', temp_thresh);
    break;
    case 'V':
      write_u16_res('V', 3);
    break;
    case 'B':
      write_u16_res('B', bat_voltage);
    break;
    case 'Q':
      write_u16_res('Q', bat_threshold);
    break;
    case 'F':
      write_u16_res('F', FIRMWARE_VERSION);
    break;
    case 'L':
      write_u16_res('L', digitalRead(LED_DISPLAY));
    break;
    case 'M':
      write_u16_res('M', digitalRead(LED_BODY));
    break;
    case 'Z':
      write_u16_res('Z', digitalRead(BUZZER));
    break;
    case 'l':
      write_u16_res('l', lcd_power_get());
    break;
    case 'e':
      write_u16_res('e', exp_board_power_get());
    break;
    case 's':
      write_u16_res('s', sensors_power_get());
    break;
    }
  break;
  case '!':
    cmd[lb] = 0;
    switch (cmd[1]) {
      case 'P':
        temp_thresh = atoi(cmd+2);
      break;
      case 'Q':
        bat_threshold = atoi(cmd+2);
      break;
      case 'L':
        if (atoi(cmd+2))
          digitalWrite(LED_DISPLAY, HIGH);
        else
          digitalWrite(LED_DISPLAY, LOW);
      break;
      case 'M':
        switch (atoi(cmd+2)) {
        case 0:
          digitalWrite(LED_BODY, LOW);
        break;
        case 1:
          digitalWrite(LED_BODY, HIGH);
        break;
        case 2:
          start_led();
        break;
        }
      break;
      case 'Z':
        start_buzzer(atoi(cmd+2));
      break;
      case 'l':
        lcd_power_set(atoi(cmd+2));
      break;
      case 'e':
        exp_board_power_set(atoi(cmd+2));
      break;
      case 's':
        sensors_power_set(atoi(cmd+2));
      break;
    }
  break;
  }

  lb = 0;
}

static void selectAlphabet(void)
{
  digitalWrite(LED_DISPLAY, LOW);
  keymapState = 0;
}

static void selectSymbols(void)
{
  digitalWrite(LED_DISPLAY, HIGH);
  keymapState = 1;
}

static void switchKeymap(void)
{
  if (keymapState)
    selectAlphabet();
  else
    selectSymbols();
}

static uint16_t mapKey(char key)
{
  if (keymapState)
    return keymapSymbols[key];

  return keymapAlpha[key];
}

static void keypadEvent(KeypadEvent key)
{
  if (Dummy.getState() != PRESSED)
    return;

  uint16_t kcode = mapKey(key);

  switch (kcode) {
  case KMAP_SWITCH:
    switchKeymap();
  break;
  case LCD_SWITCH:
    lcd_power_toggle();
  break;
  }
}

static int left_shift_ref_cnt;

static void process_keys(void)
{
  if (!Dummy.getKeys())
    return;

  int i;

  for (i = 0; i < LIST_MAX; i++) {
    if (!Dummy.key[i].stateChanged)
      continue;

    uint16_t key = mapKey(Dummy.key[i].kchar);

    if (key == KMAP_SWITCH || key == LCD_SWITCH)
      continue;

    switch (Dummy.key[i].kstate) {
    case PRESSED:
      switch (key) {
      case KMOUSE_MIDDLE:
        Mouse.press(MOUSE_MIDDLE);
      break;
      case KMOUSE_RIGHT:
        Mouse.press(MOUSE_RIGHT);
      break;
      default:
        if (key & MOD_LEFT_SHIFT) {
          if (!(left_shift_ref_cnt++))
            Keyboard.press(KEY_LEFT_SHIFT);
        }
        Keyboard.press((KeyboardKeycode)key);
      break;
      }
    break;
    case RELEASED:
      switch (key) {
      case KMOUSE_MIDDLE:
        Mouse.release(MOUSE_MIDDLE);
      break;
      case KMOUSE_RIGHT:
        Mouse.release(MOUSE_RIGHT);
      break;
      default:
        if (key & MOD_LEFT_SHIFT) {
          if (!(--left_shift_ref_cnt))
            Keyboard.release(KEY_LEFT_SHIFT);
        }
        Keyboard.release((KeyboardKeycode)key);
      break;
      }
    break;
    }
  }
}

static void thumbstick(void)
{
  static int8_t x_accel = 8;
  static int8_t y_accel = 8;
  static uint8_t btn_state = 1;

  uint8_t btn = digitalRead(THUMB_MIDDLE);

  if (btn != btn_state) {
    btn_state = btn;
    if (!btn_state)
      Mouse.press(MOUSE_LEFT);
   else
      Mouse.release(MOUSE_LEFT);
  }

  int8_t up = digitalRead(THUMB_UP);
  int8_t down = digitalRead(THUMB_DOWN);
  int8_t right = digitalRead(THUMB_RIGHT);
  int8_t left = digitalRead(THUMB_LEFT);

  int8_t x_dist = (left - right) * (x_accel/8);
  int8_t y_dist = (up - down) * (y_accel/8);

  if (x_dist) {
    if (x_accel < 80)
      x_accel++;
  } else {
    x_accel = 8;
  }

  if (y_dist) {
    if (y_accel < 80)
      y_accel++;
  } else {
    y_accel = 8;
  }

  if (x_dist || y_dist)
    Mouse.move(x_dist, y_dist, 0);
}

static uint16_t buzzer_rem_ms;

static inline void process_buzzer(void)
{
  if (!buzzer_rem_ms)
    return;

  if (--buzzer_rem_ms == 0)
    digitalWrite(BUZZER, LOW);
}

static void start_buzzer(uint16_t interval_ms)
{
  buzzer_rem_ms = interval_ms;
  digitalWrite(BUZZER, HIGH);
}

static uint16_t led_state;

static void start_led(void)
{
  led_state = 30;
}

static inline void process_led(void)
{
  if (!led_state)
    return;

  switch (led_state) {
  case 30:
    digitalWrite(LED_BODY, HIGH);
  break;
  case 20:
    digitalWrite(LED_BODY, LOW);
  break;
  case 10:
    digitalWrite(LED_BODY, HIGH);
  break;
  case 1:
    digitalWrite(LED_BODY, LOW);
  break;
  }

  led_state--;
}

SIGNAL(TIMER0_COMPA_vect)
{
  process_buzzer();
  process_led();
  thumbstick();
}

static uint16_t powered_on = 1000;

void loop(void)
{
  /* Ignore the poweroff button just after it has been pressed to turn the power on */
  if (powered_on > 0) {
    powered_on--;
  } else {
    if (!digitalRead(POWER_OFF_BTN))
      poweroff();
  }

  /* If RPi is halted beep and cut the power off */
  if (digitalRead(PI_POWEROFF_SIGNAL))
    digitalWrite(POWER_MAIN, LOW);

  process_keys();

  /* Read temperature and battery voltage every few seconds */
  static uint16_t i = 30000;
  if (i++ >= 3000) {
      read_bat_temp();
      i = 0;
  }

  process_serial();
}

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