ST7789.py

import spidev
import RPi.GPIO as GPIO
import time
import numpy as np


class ST7789(object):
    """class for ST7789  240*240 1.3inch OLED displays."""

    def __init__(self,spi,rst = 27,dc = 25,bl = 24):
        self.width = 240
        self.height = 240
        #Initialize DC RST pin
        self._dc = dc
        self._rst = rst
        self._bl = bl
        GPIO.setmode(GPIO.BCM)
        GPIO.setwarnings(False)
        GPIO.setup(self._dc,GPIO.OUT)
        GPIO.setup(self._rst,GPIO.OUT)
        GPIO.setup(self._bl,GPIO.OUT)
        GPIO.output(self._bl, GPIO.HIGH)
        #Initialize SPI
        self._spi = spi
        self._spi.max_speed_hz = 40000000

    """    Write register address and data     """
    def command(self, cmd):
        GPIO.output(self._dc, GPIO.LOW)
        self._spi.writebytes([cmd])

    def data(self, val):
        GPIO.output(self._dc, GPIO.HIGH)
        self._spi.writebytes([val])

    def Init(self):
        """Initialize dispaly"""    
        self.reset()

        self.command(0x11) 
        time.sleep(1.2)
        self.command(0x36)
        self.data(0X70)

        self.command(0x3A) 
        self.data(0x05)

        self.command(0xB2)
        self.data(0x0C)
        self.data(0x0C)
        self.data(0x00)
        self.data(0x33)
        self.data(0x33) 

        self.command(0xB7) 
        self.data(0x35)  

        self.command(0xBB)
        self.data(0x37)

        self.command(0xC0)
        self.data(0x2C)

        self.command(0xC2)
        self.data(0x01)

        self.command(0xC3)
        self.data(0x12)   

        self.command(0xC4)
        self.data(0x20)  

        self.command(0xC6) 
        self.data(0x0F)    

        self.command(0xD0) 
        self.data(0xA4)
        self.data(0xA1)

        self.command(0xE0)
        self.data(0xD0)
        self.data(0x04)
        self.data(0x0D)
        self.data(0x11)
        self.data(0x13)
        self.data(0x2B)
        self.data(0x3F)
        self.data(0x54)
        self.data(0x4C)
        self.data(0x18)
        self.data(0x0D)
        self.data(0x0B)
        self.data(0x1F)
        self.data(0x23)

        self.command(0xE1)
        self.data(0xD0)
        self.data(0x04)
        self.data(0x0C)
        self.data(0x11)
        self.data(0x13)
        self.data(0x2C)
        self.data(0x3F)
        self.data(0x44)
        self.data(0x51)
        self.data(0x2F)
        self.data(0x1F)
        self.data(0x1F)
        self.data(0x20)
        self.data(0x23)

        self.command(0x21) 

        self.command(0x29)

    def reset(self):
        """Reset the display"""
        GPIO.output(self._rst,GPIO.HIGH)
        time.sleep(0.01)
        GPIO.output(self._rst,GPIO.LOW)
        time.sleep(0.01)
        GPIO.output(self._rst,GPIO.HIGH)
        time.sleep(0.01)
        
    def SetWindows(self, Xstart, Ystart, Xend, Yend):
        #set the X coordinates
        self.command(0x2A)
        self.data(0x00)               #Set the horizontal starting point to the high octet
        self.data(Xstart & 0xff)      #Set the horizontal starting point to the low octet
        self.data(0x00)               #Set the horizontal end to the high octet
        self.data((Xend - 1) & 0xff) #Set the horizontal end to the low octet 
        
        #set the Y coordinates
        self.command(0x2B)
        self.data(0x00)
        self.data((Ystart & 0xff))
        self.data(0x00)
        self.data((Yend - 1) & 0xff )

        self.command(0x2C)    
    
    def ShowImage(self,Image,Xstart,Ystart):
        """Set buffer to value of Python Imaging Library image."""
        """Write display buffer to physical display"""
        imwidth, imheight = Image.size
        if imwidth != self.width or imheight != self.height:
            raise ValueError('Image must be same dimensions as display \
                ({0}x{1}).' .format(self.width, self.height))
        img = np.asarray(Image)
        pix = np.zeros((self.width,self.height,2), dtype = np.uint8)
        pix[...,[0]] = np.add(np.bitwise_and(img[...,[0]],0xF8),np.right_shift(img[...,[1]],5))
        pix[...,[1]] = np.add(np.bitwise_and(np.left_shift(img[...,[1]],3),0xE0),np.right_shift(img[...,[2]],3))
        pix = pix.flatten().tolist()
        self.SetWindows ( 0, 0, self.width, self.height)
        GPIO.output(self._dc,GPIO.HIGH)
        for i in range(0,len(pix),4096):
            self._spi.writebytes(pix[i:i+4096])		
        
    def clear(self):
        """Clear contents of image buffer"""
        _buffer = [0xff]*(self.width * self.height * 2)
        self.SetWindows ( 0, 0, self.width, self.height)
        GPIO.output(self._dc,GPIO.HIGH)
        for i in range(0,len(_buffer),4096):
            self._spi.writebytes(_buffer[i:i+4096])