import time
time.sleep(0.1) # Wait for USB to become ready

print("Hello, Pi Pico W!")
# Using a Matrix Keypad
# Waveshare 0.96inch OLED Module via SPI (SSD1315)
# Matrix Keypad 4x4 or 4x3
# Tony Goodhew 21th Aug 2023 - for thepihut.com

from machine import Pin, SPI
import time

# ============ Set up the display ==========
# Connect Red to 3.3V and Black to GND
import ssd1306

# Uses SPI port 0
spi_port = 0
MOSI = 19     # blue
CLK = 18      # yellow
CS = 17       # orange
RST = 16      # white   #NB MISO not used
DC = 20       # green

WIDTH = 128
HEIGHT = 64

spi = SPI(
    spi_port,
    baudrate=40000000,
    mosi=Pin(MOSI),
    sck=Pin(CLK))

oled = ssd1306.SSD1306_SPI(WIDTH,HEIGHT,
    spi,
    dc=Pin(DC),
    res=Pin(RST),
    cs=Pin(CS),
    external_vcc=False
    )

oled.fill(0) # Clear display
oled.show()

def block(x,y,w,h,c): # Filled rectangle
    for yy in range(h):
        oled.hline(x,y+yy,w,c)
# ========= Display set up =========
# === MAIN PROGRAM ===
# Map characters to keys
# These are lists of lists!
#    A 2 dimensional array

#         C0   C1   C2   C3
keys = [['1', '2', '3', 'A'], # R0
        ['4', '5', '6', 'B'], # R1
        ['7', '8', '9', 'C'], # R2
        ['*', '0', '#', 'D']] # R3
        # Pin connections left to right
row_pins = [13, 12, 11, 10]
col_pins = [9, 8, 7, 6]

cols = []  # Creat empty lists
rows = []

# Set up rows and columns
# Rows are OUTPUTS / Cols are INPUTS
for x in range(0,4):
    # Rows are OUTPUTs which we set HIGH or LOW
    rows.append(Pin(row_pins[x], Pin.OUT))
    rows[x].value(0) # Set LOW = 0V
    
    # Columns are INPUTS with internal PULL_DOWNS
    cols.append(Pin(col_pins[x], Pin.IN, Pin.PULL_DOWN))
    # Setup LED to indicate key pressed
led = Pin(25, Pin.OUT)     # Pi Pico    Comment out one of these
#led = Pin("LED", Pin.OUT) # Pi Pico W

# Short flash of LED to indicate program running
led.value(1)
time.sleep(0.5)
led.value(0)
if cols[col].value() == 1: # KEY PRESSED!
# Function to scan for a key press  - Returns the character pressed  
def scan():
    scanning = True
    while scanning:     # Until key pressed - blocking!
        for row in range(4):
            for col in range(4): 
                rows[row].high()     # Equivalent to .value(1)   
                if cols[col].value() == 1:
                    scanning = False # Terminate looping
                    k = keys[row][col] # Read character from grid
                    time.sleep(0.3) # Debounce                   
            rows[row].low()          # Equivalent to .value(0) 
    led.value(1)        # Flash LED to indicate key pressed
    time.sleep(0.1)
    led.value(0)
    return k            # Supply values to calling code
def get_value(xx,yy): # INPUT a float - includes e-format
    ns =""            # Needs 4 column keypad for full functionality
    while True:
        key = scan()           # Get a chacter from the keypad
        if key == '#':         # ENTER/RETURN       
            break              # Break out of loop
        elif (key == "*") :
            if len(ns) == 0:
                ns = ns + "-"  # Minus character (for 3 column displays)
            else:
                ns = ns[0:-1]  # Backspace
        elif key == "C":
            pass               # Not valid
        elif key == "A":
            ns = ns + "-"      # 'Minus' character
        elif key == "D":       # Decimal point
            ns = ns + "."
        elif key == "B":
            ns = ns +"e"       # Allow scientific notation values
        else:
            ns = ns + key      # Add character to string
        print(ns)              # Current string to Shell window
        block(xx,yy,128,10,0)  # Remove outdated number from display
        oled.text(ns,xx,yy,1)  # Display updated number
        oled.show()

    if len(ns) == 0:
        return 0
    if (ns.find(".") > 0) or (ns.find("e") > 0): # This is a FLOAT:
        # It contains an "." OR an "e"
        return float(ns)
    else:
        # Integer
        return int(ns)
# ======= Main Loop =========

while True:
    oled.text("N:",0,10) # Prompt
    oled.show()
    n = get_value(16,10)
    oled.text(str(n),5,25,1)
    oled.text(str(type(n)),5,35,1)
    oled.show()
    print("\n", n)
    tp = str(type(n))
    print(tp)
    time.sleep(2)
    oled.fill(0)
    if n == 0:  # HALT if zero
        break 

# Tidy up
oled.fill(0)
oled.show()