Wednesday, October 5, 2022

[SOLVED] Contents of Chip 2 in JHD128x64E (KS0108 controller based GLCD) is not getting cleared

Issue

The below shown code only clears page_1 data where main displays some text on chip 1 i.e., page_1(in code) but after set cursor col to 63+ text is written in chip 2 i.e., page_2 (in code) but then the data in it are not getting cleared while contents of page_1 does in any condition

import time
import RPi.GPIO as GPIO

# timing constants 
E_PULSE = 0.0000001  
E_DELAY = 0.0000005  

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(4, GPIO.OUT)  # rs
GPIO.setup(7, GPIO.OUT)  # rw
GPIO.setup(8, GPIO.OUT)  # en
GPIO.setup(9, GPIO.OUT)  # d0
GPIO.setup(10, GPIO.OUT)  # d1
GPIO.setup(11, GPIO.OUT)  # d2
GPIO.setup(14, GPIO.OUT)  # d3
GPIO.setup(15, GPIO.OUT)  # d4
GPIO.setup(17, GPIO.OUT)  # d5
GPIO.setup(18, GPIO.OUT)  # d6
GPIO.setup(22, GPIO.OUT)  # cs1
GPIO.setup(23, GPIO.OUT)  # cs2
GPIO.setup(24, GPIO.OUT)  # rst

# Set pins to low
GPIO.output(4, 0)  # rs
GPIO.output(7, 0)  # rw
GPIO.output(8, 0)  # en
GPIO.output(22, 0)  # cs1
GPIO.output(23, 0)  # cs2
GPIO.output(24, 0)  # rst


def data_write(value, mode):
    GPIO.setup(25, GPIO.OUT)  # d7 as o/p
    GPIO.output(7, 0)
    GPIO.output(4, mode)
    GPIO.output(9, value & 0x01)
    GPIO.output(10, value & 0x02)
    GPIO.output(11, value & 0x04)
    GPIO.output(14, value & 0x08)
    GPIO.output(15, value & 0x10)
    GPIO.output(17, value & 0x20)
    GPIO.output(18, value & 0x40)
    GPIO.output(25, value & 0x80)

    # Toggle E
    time.sleep(E_DELAY)
    GPIO.output(8, True)
    time.sleep(E_PULSE)
    GPIO.output(8, False)
    time.sleep(E_DELAY)


# Waiting write operation complete by listening BUSY signal
def busy_chk():
    GPIO.setup(25, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

    GPIO.output(7, 1)
    GPIO.output(4, 0)

    time.sleep(E_DELAY)
    GPIO.output(8, True)
    time.sleep(E_PULSE)
    GPIO.output(8, False)
    time.sleep(E_DELAY)

    # Wait until BUSY(d7) is off
    while GPIO.input(25):
        pass

    GPIO.setup(25, GPIO.OUT)  # set d7 back to Output


def page_1():
    GPIO.output(22, 1)  # Select left controller
    GPIO.output(23, 0)  # Select right controller


def page_2():
    GPIO.output(22, 0)  # Select left controller
    GPIO.output(23, 1)  # Select right controller


def init_disp():
    GPIO.output(24, 1)  # Reset the display
    page_1()
    data_write(0x3F, 0)  # command to turn ON LCD
    page_2()
    data_write(0x3F, 0)  # command to turn ON LCD

    page_1()
    data_write(0xC0, 0)  # start line command
    page_2()
    data_write(0xC0, 0)  # start line command


def clr_disp():
    page_1()
    for y in range(8):
        set_cursor(0, y)
        for i in range(64):
            data_write(0x00, 1)

    page_2()
    for y in range(8):
        set_cursor(0, y)
        for i in range(64):
            data_write(0x00, 1)


def set_cursor(col, row):
    if row >= 8:
        raise ValueError('Invalid Input')
    pass
    data_write((row | 0xB8) & 0xBF, 0)
    if col < 63:
        page_1()  # Enable left controller
        data_write((col | 0x40) & 0x7F, 0)
    else:
        page_2()  # Enable right controller
        data_write(((col - 64) | 0x40) & 0x7F, 0)


def main():
    init_disp()
    busy_chk()
    clr_disp()
    set_cursor(0, 0)
    data_write(0x02, 1)
    data_write(0x02, 1)
    data_write(0xFE, 1)
    data_write(0x02, 1)


if __name__ == "__main__":
    main()

this code below is supposed to clear dots of page_2

def clr_disp():
    page_1()
    for y in range(8):
        set_cursor(0, y)
        for i in range(64):
            data_write(0x00, 1)

    page_2()
    for y in range(8):
        set_cursor(0, y)
        for i in range(64):
            data_write(0x00, 1)

some please tell me where I'm going wrong, i'm not very good at coding

thank you


Solution

In function clr_disp() you first call page_2() but then in for loop you call set_cursor(0, y) and because you pass 0 as col we get into first if condition which resets the cursor back to page1.

You can test this if you comment the first part of your clear display, you should see that your second part also clears the page1.

You should clear your display like this:

def clr_disp():
    for y in range(8):
        set_cursor(0, y)
        for i in range(64):
            data_write(0x00, 1)

    for y in range(8):
        set_cursor(64, y)
        for i in range(64):
            data_write(0x00, 1)


Answered By - Grekkq
Answer Checked By - Mildred Charles (WPSolving Admin)
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