The Imperializer: MM to Inch Conversion Box!

PLEASE READ! IMPORTANT SAFETY NOTE REGARDING LITHIUM POLYMER BATTERIES!

Click HERE to download The Imperializer Fusion 360 Solid Model CAD file!

The Imperializer!

 

Imperializer Assembly Video

 

 

Bill of Materials:

4x3 Keypad

In/MM Switch

Power Switch

Small Items

Imperializer Arduino Circuit Layout

Troubleshooting

LCD backpacks with the PCF8574AT chip use the address 0x37, while those with the PCF8574T chip use 0x27. If upon uploading the code to your nano, the LCD flashes a row of blocks on the upper row then goes dark, try the i2c address change mentioned in the comment at line 19.

Required Libraries

Only one library is not available from within the arduino IDE. Download and copy the ‘NewLiquidCrystal’ folder to program files/arduino/libraries.

Click here to download the NewLiquidCrystal library

Arduino Code

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/*

|| NYCCNC IMPERIALIZER

|| -version 1.5

|| -author Ed Rees

|| -1/15/2018

|| -Copyright Saunders Machine Works, LLC 2018

*/


// required libraries below. If necessary, search for them from the dropdown menu 'Sketch>Include Library>Libraries Manager' and install from there as prompted.

#include <Wire.h> // included with IDE.

#include <avr/sleep.h> // included with IDE. For whatever reason it doesn't turn orange like most libraries do, but it works fine.

#include <Keypad.h> // by Mark Stanley and Alexander Brevig, can be found in the libraries manager.

#include <LiquidCrystal_I2C.h> // available at https://arduino-info.wikispaces.com/LCD-Blue-I2C#v1

LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Set the LCD I2C address to "0x3F". If LCD display is blank, try changing I2C address to "0x27"

float entry = 0; // whole number value.

float a = 0;

float b = 0;

float c = 0;

float d = 0;

float decimalValue = 0; // total decimal number value.

float decimalEntry = 0; // most recent number entered while in decimal mode.

float cursBreak = 0; // breaks main loop to position cursor.

int decimalPlace = 0; // records decimal place for decimal value calculation.

int keyCount = 0; // counts key presses to prevent overflow.

int toggleState = 0; // records state of unit toggle switch.

int cursorCount = 0;

int cursorRow = 1;

int divisor = 0; // used for unit conversion math.

int sleepDelay = 15000;

int sleepTimer = sleepDelay;

int toggleLatch = 0; // current state of the button.

int lastToggleLatch = 0; // previous state of the button.

const int togglePin = 11; // declares digital pin 11 as unit toggle pin.

bool decimalMode = false; // toggles between Inch to Millimeter and Millimeter to Inch conversion.

bool decSkip = true; // used to skip cursor decimal count when entry is less than one.

bool decLatch = false; // used to avoid cursor moving undesirably when decimal button is pushed more than once per entry.

bool wakeMode = false;

bool cursorBump = true;

char customKey;

const byte ROWS = 4;

const byte COLS = 3;

char keys[ROWS][COLS] = {

{'1', '2', '3'},

{'4', '5', '6'},

{'7', '8', '9'},

{'C', '0', 'D'}

};

byte rowPins[ROWS] = {9, 4, 5, 7}; // connect to the row pinouts of the keypad

byte colPins[COLS] = {8, 10, 6}; // connect to the column pinouts of the keypad

Keypad customKeypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup()

{

pinMode(togglePin, INPUT);

pinMode(3, INPUT);

pinMode(13, OUTPUT);

digitalWrite(13, HIGH);

lcd.begin(16, 2);

lcd.clear();

lcd.print("0.0000");

lcd.setCursor(0, 1);

lcd.print("0.0000");

if (toggleState == HIGH) // determine initial unit toggle state and set cursor row accordingly.

{

cursorRow = 0;

}

else

{

cursorRow = 1;

}

}

void loop()

{

customKey = customKeypad.getKey();

toggleState = digitalRead(togglePin);

toggleLatch = digitalRead(togglePin);

a = (entry + decimalValue);

b = (a * 25.4);

c = (a / 25.4);

d = a;

if (sleepTimer <= 1) // puts device to sleep when sleep timer runs out.

{

pinMode(8, OUTPUT);

digitalWrite(8, LOW);

sleepNow();

}

if (toggleLatch != lastToggleLatch)

{

sleepTimer = sleepDelay; // reset sleep timer if unit toggle is changed

lcd.begin(16, 2);

lcd.setCursor(0, 0);

if (toggleState == HIGH)

{

cursorRow = 0;

}

else

{

cursorRow = 1;

}

lcd.clear();

cursBreak = d + .5;

}

if (cursBreak == d)

{

lcd.setCursor(cursorCount, cursorRow);

lcd.blink();

}

switch (customKey)

{

case '0' ... '9':

sleepTimer = sleepDelay; // reset sleep timer if a key is pressed.

if (decimalMode == true) // determine if in decimal entry mode:

{

if (keyCount < 7 && decimalPlace < 4) // prevents overflow.

{

keyCount++; // increment key press count by one.

cursorCount++; // increment cursor ount by one.

decimalPlace++; // increment decimal place by one.

divisor = 0.5 + pow(10, decimalPlace); // divisor is set equal to (10^decimalPlace), plus 0.5 to ensure proper rounding.

decimalEntry = (customKey - '0') / (float)divisor; // decimal entry set equal to key entered, and divided by divisor.

decimalValue = decimalValue + decimalEntry; // new decimal value set equal to previous decimal value plus last decimal entry.

}

break;

}

else

{

if (keyCount < 7 && decimalPlace < 4)

{

keyCount++;

if (entry > 0)

{

cursorCount++;

}

if (entry <= 9 && entry > 0 && cursorBump == true)

{

cursorCount++;

cursorBump = false;

}

entry = entry * 10 + (customKey - '0'); // increments digit input position. ie: 1(*10)+5 = 15.

}

break;

}

case 'D': //collects decimal keypress.

decimalMode = true;

cursBreak = (d + .5);

if (decLatch == false && entry == 0)

{

cursorCount++;

}

if (decSkip == true)

{

cursorCount++;

}

decSkip = false;

decLatch = true;

break;

case 'C': // clear- reset relevant variables to defaults and return to title screen.

if(wakeMode == false)

{

cursBreak = d;

entry -= entry;

decimalMode = false;

decimalPlace = 0;

decimalValue -= decimalValue;

decSkip = true;

decLatch = false;

keyCount -= keyCount;

cursorCount -= cursorCount;

cursorBump = true;

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("0.0000");

lcd.setCursor(0, 1);

lcd.print("0.0000");

break;

}

}

if (toggleState == HIGH && cursBreak != d) // if toggle is in inch mode:

{

lcd.setCursor(0, 0);

lcd.print(a, 4); //in

lcd.setCursor(0, 1);

lcd.print (b, 4); //mm

}

else if (cursBreak != d) //if toggle is NOT in inch mode:

{

lcd.setCursor(0, 0);

lcd.print (c, 4); //mm

lcd.setCursor(0, 1);

lcd.print(a, 4); //in

}

cursBreak = d;

sleepTimer -= 1; //counts down from sleep delay value.

if (wakeMode == true) // upon waking, reset relevant variables to defaults and return to title screen.

{

pinMode(togglePin, INPUT);

pinMode(13, OUTPUT);

digitalWrite(13, HIGH);

lcd.begin(16, 2);

if (toggleState == HIGH) // if toggle is in inch mode:

{

lcd.setCursor(0, 0);

lcd.print(a, 4); //in

lcd.setCursor(0, 1);

lcd.print (b, 4); //mm

}

else //if toggle is NOT in inch mode:

{

lcd.setCursor(0, 0);

lcd.print (c, 4); //mm

lcd.setCursor(0, 1);

lcd.print(a, 4); //in

}

wakeMode = false;

}

lastToggleLatch = toggleLatch;

}

//Sleep functions below:

void sleepNow ()

{

digitalWrite(13, LOW);

set_sleep_mode (SLEEP_MODE_PWR_DOWN);

sleep_enable (); // enables the sleep bit in the mcucr register

attachInterrupt (digitalPinToInterrupt (3), wake, LOW); // wake up on low level on D3

sleep_mode (); // here the device is actually put to sleep

detachInterrupt (digitalPinToInterrupt (3)); // stop LOW interrupt on D3

}

void wake () // interrupt service routine in sleep mode

{

sleep_disable (); // first thing after waking from sleep:

sleepTimer = sleepDelay;

pinMode(8, INPUT);

wakeMode = true;

}

HEX upload via Xloader

You may also simply upload the compiled HEX file directly to the Nano using Xloader.

Click here to download Xloader

Click here to download the HEX file

Use these settings, change the COM port to that which your Nano is connected to, and navigate to wherever you unzipped the HEX file.

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