#!/usr/bin/python
########################################################################
#
# A Python script for controlling the Adafruit 1.8" TFT LCD module
# from a Raspbery Pi.
#
# Author : Bruce E. Hall, W8BH <bhall66@gmail.com>
# Date : 27 Apr 2013
#
# This module uses the ST7735 controller and SPI data interface
#
#
# For more information, see w8bh.net
#
########################################################################
import RPi.GPIO as GPIO
import time
#TFT to RPi connections
# PIN TFT RPi
# 1 backlight 3v3
# 2 MISO <none>
# 3 CLK GPIO 24
# 4 MOSI GPIO 23
# 5 CS-TFT GND
# 6 CS-CARD <none>
# 7 D/C GPIO 25
# 8 RESET <none>
# 9 VCC 3V3
# 10 GND GND
SCLK = 24
SDAT = 23
DC = 25
pins = [SCLK,SDAT,DC]
#RGB888 Color constants
BLACK = 0x000000
RED = 0xFF0000
GREEN = 0x00FF00
BLUE = 0x0000FF
WHITE = 0xFFFFFF
COLORSET = [RED,GREEN,BLUE,WHITE]
#ST7735 commands
SWRESET = 0x01 #software reset
SLPOUT = 0x11 #sleep out
DISPON = 0x29 #display on
CASET = 0x2A #column address set
RASET = 0x2B #row address set
RAMWR = 0x2C #RAM write
MADCTL = 0x36 #axis control
COLMOD = 0x3A #color mode########################################################################
#
# Low-level routines
# These routines access GPIO directly
#
def SetPin(pinNumber,value):
 #sets the GPIO pin to desired value (1=on,0=off)
 GPIO.output(pinNumber,value)
def InitIO():
 GPIO.setmode(GPIO.BCM)
 GPIO.setwarnings(False)
 for pin in pins:
 GPIO.setup(pin,GPIO.OUT)
 GPIO.output(SCLK,0) #start with clock line low


########################################################################
#
# Bit-Banging (software) SPI routines:
#
#
def PulseClock():
#pulses the serial clock line HIGH
SetPin(SCLK,1) #bit clocked on low-high transition
SetPin(SCLK,0) #no delay since python is slow
def WriteByte(value, data=True):
"sends byte to display using software SPI"
mask = 0x80 #start with bit7 (msb)
SetPin(DC,data) #low = command; high = data
for b in range(8): #loop for 8 bits, msb to lsb
SetPin(SDAT,value & mask) #put bit on serial data line
PulseClock() #clock in the bit
mask >>= 1 #go to next bit
def WriteCmd(value):
"Send command byte to display"
WriteByte(value,False) #set D/C line to 0 = command
def WriteWord (value):
"sends a 16-bit word to the display as data"
WriteByte(value >> 8) #write upper 8 bits
WriteByte(value & 0xFF) #write lower 8 bits
def WriteList (byteList):
"Send list of bytes to display, as data"
for byte in byteList: #grab each byte in list
WriteByte(byte) #and send it
def Write888(value,reps=1):
"sends a 24-bit RGB pixel data to display, with optional repeat"
red = value>>16 #red = upper 8 bits
green = (value>>8) & 0xFF #green = middle 8 bits
blue = value & 0xFF #blue = lower 8 bits
RGB = [red,green,blue] #assemble RGB as 3 byte list
for a in range(reps): #send RGB x optional repeat
WriteList(RGB)########################################################################
#
# ST7735 driver routines:
#
#
def InitDisplay():
"Resets & prepares display for active use."
WriteCmd (SWRESET) #software reset, puts display into sleep
time.sleep(0.2) #wait 200mS for controller register init
WriteCmd (SLPOUT) #sleep out
time.sleep(0.2) #wait 200mS for TFT driver circuits
WriteCmd (DISPON) #display on!
def SetAddrWindow(x0,y0,x1,y1):
"sets a rectangular display window into which pixel data is placed"
WriteCmd(CASET) #set column range (x0,x1)
WriteWord(x0)
WriteWord(x1)
WriteCmd(RASET) #set row range (y0,y1)
WriteWord(y0)
WriteWord(y1)
def DrawPixel(x,y,color):
"draws a pixel on the TFT display"
SetAddrWindow(x,y,x,y)
WriteCmd(RAMWR)
Write888(color)
def FillRect(x0,y0,x1,y1,color):
"fills rectangle with given color"
width = x1-x0+1
height = y1-y0+1
SetAddrWindow(x0,y0,x1,y1)
WriteCmd(RAMWR)
Write888(color,width*height)
def FillScreen(color):
"Fills entire screen with given color"
FillRect(0,0,127,159,color)
def ClearScreen():
"Fills entire screen with black"
FillRect(0,0,127,159,BLACK)
########################################################################
#
# Testing routines:
#
#
def TimeDisplay():
"Measures time required to fill display twice"
startTime=time.time()
print " Now painting screen GREEN"
FillScreen(GREEN)
print " Now clearing screen"
ClearScreen()
elapsedTime=time.time()-startTime
print " Elapsed time %0.1f seconds" % (elapsedTime)########################################################################
#
# Main Program
#
print "Adafruit 1.8 TFT display demo"
InitIO()
InitDisplay()
TimeDisplay()
print "Done."
# END ###############################################################