Display char or CGRAM using uasyncio method

[nikhiledutech]

Hello,

I am using displaying data on LCD using async method given by Sir Peter Hinch. But i wanted to know have anyone use the async module, to display charachter at different position on LCD.

And is there any way to use async method to display CGRAM, like Sir Dhylands have done in LCD interfacing module ?

[pythoncoder]

I'm not sure which LCD or which of my libraries you're using. My touch GUI for the official LCD160CR display uses uasyncio and can display text (and other objects) anywhere on the screen.

[nikhiledutech]

Hi sir,
i am talking about this driver
https://github.com/peterhinch/micropyth ... er/HD44780

[pythoncoder]

The driver simply maps a fixed-length line of text onto a row of the display. To display a line with specific formatting I'd create a new string using the string format operator and re-display it. It's not very efficient but with a display of typically 2 rows of 16 columns I thought the complexity of a more fully featured driver wasn't justified, either in terms of refresh speed or RAM allocation.

If you're still concerned others have written HD44780 drivers which may be more fully featured.

[nikhiledutech]

okay, i just assigned different spaces to different variables and use string formatting.

Code: Select all

one 		= ""		
two 		= " "		
three 		= "  "		
four 		= "   "		
five 		= "    "		
six 		= "     "		
seven	 	= "      "		
eight 		= "       "		
nine 		= "        "		
ten 		= "         "		
elleven		= "          "		
twelve 		= "           "		
thirteen 	= "            "		
fourteen 	= "             "		
fifteen 	= "              "		
sixteen 	= "               "		



#Cursor position are from 0 to 15
async def ASK25_LCD_Display_Character(a):
	lcd[0] = '{}A'.format(a)
	await asyncio.sleep(1)

position = [one, two, three, four, five, six, seven, eight, nine, ten, \
elleven, twelve, thirteen, fourteen, fifteen, sixteen]



#for x in range(16):
#	loop = asyncio.get_event_loop()
#	loop.run_until_complete(ASK25_LCD_Display_Character(position[x]))


loop = asyncio.get_event_loop()

x = 0
while True:
	if (x < 16):
		loop.run_until_complete(ASK25_LCD_Display_Character(position[x]))
		pyb.delay(1)
		x+=1
		if (x == 16):
			x = 0

[pythoncoder]

You might like to consider

Code: Select all

'{:>{n}s}'.format('A', n=6)

This can be used as follows:

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>>> def print_at(st, col):
...     return '{:>{col}s}'.format(st, col=col+len(st))
... 
>>> print_at('dog', 2)
'  dog'
>>> 

This version will erase any characters after the passed string (i.e. it will always have the specified width):

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def print_at(st, col, width=16):
    return '{:>{col}s}{:{t}s}'.format(st,'', col=col+len(st), t = width-(col+len(st)))

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>>> print_at('cat', 2)
'  cat           '
>>> len(_)
16
>>> 

Further, I don't think you've grasped how to use uasyncio. I suggest you look at the tutorial in this repo. Normally you run the event loop for the duration of your program rather than starting and stopping it repeatedly.

[nikhiledutech]

okay. thanks sir for suggestion.

Actually i have uasyncio module only with lcd, so didn't go in much depth of module. But i guess i need to understand how to use uasyncio now.

[nikhiledutech]

Hey Sir,
I used method given by you, and it worked well.

Now i am using same method to display scrolling messages . i have created a function with parameter passed Data, row and Shift Direction.

I have given my code below.

Problem is that when my message gets scrolled out of LCD (i.e message = " exam", message[-1] gets scrolled out), i want that message[-1] to display at the col 1 of LCD along with message[0:2] displayed at last columns of LCD.

At present, the message will be completely scolled out of LCD, than it comes on col 1 again.

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async def Display_Character(data, row, col):
	lcd[row] = '{:>{col}s}'.format(data, col = col + len(data) )
	await asyncio.sleep_ms(500)



Right = 0
Left = 1
#Function to show scrolling message
async def ASK25_LCD_Display_Data_Shift(data, row, Shift_Direction):
	col = 0
	if (Shift_Direction == Right):					#Testing Shift Direction	
		position = Right				

	elif (Shift_Direction == Left):
		position = Left											

	while True:
		if (col < 16):	
			col+=1
		else:
			col = 0	
			
		loop.run_until_complete(Display_Character(data, row, col ))
			

loop.run_until_complete(ASK25_LCD_Display_Data_Shift('ABC', 0, Right))

[nikhiledutech]

And Sir how to use this same module for 8 bit mode.

I have changed the initstring to this INITSTRING = b'\x33\x32\x38\x0C\x06\x01' 0x38 means i have selected 8 bit mode as per my knowledge.

And in Pin list i have defined my pins : (RS, E, D0 -D8 pin)
PINLIST = ('PB1','PB5','PE8','PE9','PE10','PE11','PE12','PE13','PE14','PE15')


here goes def__init__ function .

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def __init__(self, pinlist, cols, rows = 2): # Init with pin nos for enable, rs, D4, D5, D6, D7
        self.initialising = True
        self.LCD_E = Pin(pinlist[1], Pin.OUT)    # Create and initialise the hardware pins
        self.LCD_RS = Pin(pinlist[0], Pin.OUT)
        self.datapins = [Pin(pin_name, Pin.OUT) for pin_name in pinlist[2:]]
        self.d0_pin = pinlist[2]
        self.d1_pin = pinlist[3]
        self.d2_pin = pinlist[4]
        self.d3_pin = pinlist[5]
        self.d4_pin = pinlist[6]
        self.d5_pin = pinlist[7]
        self.d6_pin = pinlist[8]
        self.d7_pin = pinlist[9]
        self.cols = cols
        self.rows = rows
        self.lines = [""] * self.rows
        self.dirty = [False] * self.rows
        for thisbyte in LCD.INITSTRING:
            self.lcd_byte(thisbyte, LCD.CMD)
            self.initialising = False           # Long delay after first byte only
        loop = asyncio.get_event_loop()
        loop.create_task(self.runlcd())

And here i tried to the code lookiong at Sir @dhylands code :

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 Writes 8 bits of data to the LCD.
     def lcd_8bits(self, value):

        self.d1_pin.value(value & 0x08)
        self.d2_pin.value(value & 0x04)
        self.d1_pin.value(value & 0x02)
        self.d0_pin.value(value & 0x01)
        self.hal_write_4bits(value >> 4)

        self.d7_pin.value(nibble & 0x08)
        self.d6_pin.value(nibble & 0x04)
        self.d5_pin.value(nibble & 0x02)
        self.d4_pin.value(nibble & 0x01)
        self.LCD_E.value(True)                  # Toggle the enable pin
        time.sleep_us(LCD.E_PULSE)
        self.LCD_E.value(False)

Is that correct way ? Or can you guide me through it ?

[pythoncoder]

Sorry, I have no experience of 8 bit mode: I see no point in using more pins than necessary.