和这篇也算是姊妹篇，只是一个侧重SPI协议，一个侧重显示驱动。
总线学习3--SPI-CSDN博客
驱动来自：https://github.com/boochow/MicroPython-ST7735
所以这里主要还是学习。
代码Init
def __init__( self, spi, aDC, aReset, aCS) :
"""aLoc SPI pin location is either 1 for 'X' or 2 for 'Y'.
aDC is the DC pin and aReset is the reset pin."""
self._size = ScreenSize
self._offset = bytearray([0,0])
self.rotate = 0 #Vertical with top toward pins.
self._rgb = True #color order of rgb.
self.tfa = 0 #top fixed area
self.bfa = 0 #bottom fixed area
self.dc = machine.Pin(aDC, machine.Pin.OUT, machine.Pin.PULL_DOWN)
self.reset = machine.Pin(aReset, machine.Pin.OUT, machine.Pin.PULL_DOWN)
self.cs = machine.Pin(aCS, machine.Pin.OUT, machine.Pin.PULL_DOWN)
self.cs(1)
self.spi = spi
self.colorData = bytearray(2)
self.windowLocData = bytearray(4)很多PIN口设置，比较特别的是offset，colorData，windowsLocData。
屏幕初始化
def initr( self ) :
'''Initialize a red tab version.'''
self._reset()
self._writecommand(TFT.SWRESET) #Software reset.
time.sleep_us(150)
self._writecommand(TFT.SLPOUT) #out of sleep mode.
time.sleep_us(500)
data3 = bytearray([0x01, 0x2C, 0x2D]) #fastest refresh, 6 lines front, 3 lines back.
self._writecommand(TFT.FRMCTR1) #Frame rate control.
self._writedata(data3)
self._writecommand(TFT.FRMCTR2) #Frame rate control.
self._writedata(data3)
data6 = bytearray([0x01, 0x2c, 0x2d, 0x01, 0x2c, 0x2d])
self._writecommand(TFT.FRMCTR3) #Frame rate control.
self._writedata(data6)
time.sleep_us(10)
data1 = bytearray(1)
self._writecommand(TFT.INVCTR) #Display inversion control
data1[0] = 0x07 #Line inversion.
self._writedata(data1)
self._writecommand(TFT.PWCTR1) #Power control
data3[0] = 0xA2
data3[1] = 0x02
data3[2] = 0x84
self._writedata(data3)
self._writecommand(TFT.PWCTR2) #Power control
data1[0] = 0xC5 #VGH = 14.7V, VGL = -7.35V
self._writedata(data1)
data2 = bytearray(2)
self._writecommand(TFT.PWCTR3) #Power control
data2[0] = 0x0A #Opamp current small
data2[1] = 0x00 #Boost frequency
self._writedata(data2)
self._writecommand(TFT.PWCTR4) #Power control
data2[0] = 0x8A #Opamp current small
data2[1] = 0x2A #Boost frequency
self._writedata(data2)
self._writecommand(TFT.PWCTR5) #Power control
data2[0] = 0x8A #Opamp current small
data2[1] = 0xEE #Boost frequency
self._writedata(data2)
self._writecommand(TFT.VMCTR1) #Power control
data1[0] = 0x0E
self._writedata(data1)
self._writecommand(TFT.INVOFF)
self._writecommand(TFT.MADCTL) #Power control
data1[0] = 0xC8
self._writedata(data1)
self._writecommand(TFT.COLMOD)
data1[0] = 0x05
self._writedata(data1)
self._writecommand(TFT.CASET) #Column address set.
self.windowLocData[0] = 0x00
self.windowLocData[1] = 0x00
self.windowLocData[2] = 0x00
self.windowLocData[3] = self._size[0] - 1
self._writedata(self.windowLocData)
self._writecommand(TFT.RASET) #Row address set.
self.windowLocData[3] = self._size[1] - 1
self._writedata(self.windowLocData)
dataGMCTRP = bytearray([0x0f, 0x1a, 0x0f, 0x18, 0x2f, 0x28, 0x20, 0x22, 0x1f,
0x1b, 0x23, 0x37, 0x00, 0x07, 0x02, 0x10])
self._writecommand(TFT.GMCTRP1)
self._writedata(dataGMCTRP)
dataGMCTRN = bytearray([0x0f, 0x1b, 0x0f, 0x17, 0x33, 0x2c, 0x29, 0x2e, 0x30,
0x30, 0x39, 0x3f, 0x00, 0x07, 0x03, 0x10])
self._writecommand(TFT.GMCTRN1)
self._writedata(dataGMCTRN)
time.sleep_us(10)
self._writecommand(TFT.DISPON)
time.sleep_us(100)
self._writecommand(TFT.NORON) #Normal display on.
time.sleep_us(10)
self.cs(1)这个就是一系列SPI命令的组合。这部分一般是来自厂家或者自己去数据手册翻。。
初始完屏幕之后，就可以做各种操作了。
待续。。。
