Joy-it LCD Display 16x2 with Buttons User guide

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LCD Display 16x2 with Buttons

Ausgabe 10.11.2017 Copyright by Joy-IT 1

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Index

1. Connecng the Display

2. Installing the System

3. Usage & Example-Code

4. Support

LCD Display 16x2 with Buttons

Ausgabe 10.11.2017 Copyright by Joy-IT 2

LCD Display 16x2 with Buttons

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Dear customer

thank you for purchasing our product.

Please nd our instrucons below.

1. Connecting the Display

Plug the display onto the pin header of your Raspberry Pi so that the display is placed over your
Raspberry Pi.
As soon as you power your Raspberry Pi, the displays backlight should start to light.

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LCD Display 16x2 with Buttons

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2. Installing the System

You can skip this step, if you are already running the latest Raspbian soware on your Raspberry Pi,
and connue with the next step.
If not, please follow the instrucons.

Install the latest Raspbian-System-Image to your SD-Card.
You can download the image here.
Transfer the image with a suitable program (e.g. Etcher).
You can insert the SD-Card to your Raspberry Pi and start the system when the transfer progress is
complete.

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LCD Display 16x2 with Buttons

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3. Usage & Example-Code

Your display is ready to use.
No further installaons are required.
It may appear that you manually need to adjust the contrast before you are able to read anything on
the display.

Adjust the contrast by rotang the screw with a small screw-driver unl the contrast is ne.

To use the display, you can either download the example-code or create a new le and insert the
code.

To create a new le, enter the following command:

sudo nano lcd16x2.py

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import time
import RPi.GPIO as GPIO

# PIN-Configuration

LCD_RS = 7 #GPIO7 = Pi pin 26
LCD_E = 8 #GPIO8 = Pi pin 24
LCD_D4 = 17 #GPIO17 = Pi pin 11
LCD_D5 = 18 #GPIO18 = Pi pin 12
LCD_D6 = 27 #GPIO21 = Pi pin 13
LCD_D7 = 22 #GPIO22 = Pi pin 15
OUTPUTS = [LCD_RS,LCD_E,LCD_D4,LCD_D5,LCD_D6,LCD_D7]

#Button-PINs

SW1 = 4 #GPIO4 = Pi pin 7
SW2 = 23 #GPIO16 = Pi pin 16
SW3 = 10 #GPIO10 = Pi pin 19
SW4 = 9 #GPIO9 = Pi pin 21
INPUTS = [SW1,SW2,SW3,SW4]

#HD44780 Controller Commands

CLEARDISPLAY = 0x01
SETCURSOR = 0x80

#Line Addresses. (Pick one. Comment out whichever doesn't apply)
#LINE = [0x00,0x40,0x14,0x54] #for 20x4 display

LINE = [0x00,0x40] #for 16x2 display

########################################################################

def InitIO():

#Sets GPIO pins to input & output, as required by LCD board
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
for lcdLine in OUTPUTS:
GPIO.setup(lcdLine, GPIO.OUT)
for switch in INPUTS:
GPIO.setup(switch, GPIO.IN, pull_up_down=GPIO.PUD_UP)

def CheckSwitches():

#Check status of all four switches on the LCD board
val1 = not GPIO.input(SW1)
val2 = not GPIO.input(SW2)
val3 = not GPIO.input(SW3)
val4 = not GPIO.input(SW4)
return (val4,val1,val2,val3)

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def PulseEnableLine():

#Pulse the LCD Enable line; used for clocking in data
mSec = 0.0005 #use half-millisecond delay
time.sleep(mSec) #give time for inputs to settle
GPIO.output(LCD_E, GPIO.HIGH) #pulse E high
time.sleep(mSec)
GPIO.output(LCD_E, GPIO.LOW) #return E low
time.sleep(mSec) #wait before doing anything else

def SendNibble(data):

#sends upper 4 bits of data byte to LCD data pins D4-D7
GPIO.output(LCD_D4, bool(data & 0x10))
GPIO.output(LCD_D5, bool(data & 0x20))
GPIO.output(LCD_D6, bool(data & 0x40))
GPIO.output(LCD_D7, bool(data & 0x80))

def SendByte(data,charMode=False):

#send one byte to LCD controller
GPIO.output(LCD_RS,charMode) #set mode: command vs. char
SendNibble(data) #send upper bits first
PulseEnableLine() #pulse the enable line
data = (data & 0x0F)<< 4 #shift 4 bits to left
SendNibble(data) #send lower bits now
PulseEnableLine() #pulse the enable line

def InitLCD():

#initialize the LCD controller & clear display
SendByte(0x33) #initialize
SendByte(0x32) #set to 4-bit mode
SendByte(0x28) #2 line, 5x7 matrix
SendByte(0x0C) #turn cursor off (0x0E to enable)
SendByte(0x06) #shift cursor right
SendByte(CLEARDISPLAY) #remove any stray characters on display

########################################################################

def SendChar(ch):

SendByte(ord(ch),True)

def ShowMessage(string):

#Send string of characters to display at current cursor position
for character in string:
SendChar(character)

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def GotoLine(row):

#Moves cursor to the given row
#Expects row values 0-1 for 16x2 display; 0-3 for 20x4 display
addr = LINE[row]
SendByte(SETCURSOR+addr)

########################################################################
# Main Program

print "LCD program starting. Press CTRL+C to stop."

InitIO()
InitLCD()
ShowMessage('Press a button!')

while (True):

GotoLine(1)
switchValues = CheckSwitches()
decimalResult = " %d %d %d %d" % switchValues
ShowMessage(decimalResult)

# time.sleep(0.2)

You can save the le by pressing CTRL+O and leave the editor by pressing CTRL+X.
You can start the program with the following command:

sudo python lcd16x2.py

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4. Support

We also support you aer your purchase.
If there are any quesons le or if you encounter any problems, please feel free to contact us by mail,
phone or by our cket-supportsystem on our website.

E-Mail: [e-mail]

Ticket-System: hp://support.joy-it.net

Phone: [phone] – 66 (11- 18 Uhr)

Please visit our website for more informaons:

www.joy-it.net

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