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(0x36)
        self.data(0x70)                 #self.data(0x00)

        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(0x19)

        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(0x11)

        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])