我有一个问题 在我的 RPi 上使用 4x16 LCD 显示器。我连接了显示器并使用本教程对其进行了测试
现在我想通过 USB 从我的 arduino 接收数据。这个简单的教程在这里向我展示了如何做到这一点
我的问题：我怎样才能在我的显示器上获得数据？它应该更新所有的时间。我尝试了一段时间 1: 循环，但出现多个错误。
有人能帮我吗？有没有更简单的方法？还是图书馆之类的东西？
谢谢
到目前为止我的代码（几乎所有内容都来自 LCD 教程）：
#import
import RPi.GPIO as GPIO
import time
import serial
ser = serial.Serial('/dev/ttyACM0', 9600)
# Define GPIO to LCD mapping
LCD_RS = 7
LCD_E = 8
LCD_D4 = 25
LCD_D5 = 24
LCD_D6 = 23
LCD_D7 = 18
LED_ON = 15
# Define some device constants
LCD_WIDTH = 20 # Maximum characters per line
LCD_CHR = True
LCD_CMD = False
LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line
LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line
# Timing constants
E_PULSE = 0.00005
E_DELAY = 0.00005
def main():
# Main program block
GPIO.setmode(GPIO.BCM) # Use BCM GPIO numbers
GPIO.setup(LCD_E, GPIO.OUT) # E
GPIO.setup(LCD_RS, GPIO.OUT) # RS
GPIO.setup(LCD_D4, GPIO.OUT) # DB4
GPIO.setup(LCD_D5, GPIO.OUT) # DB5
GPIO.setup(LCD_D6, GPIO.OUT) # DB6
GPIO.setup(LCD_D7, GPIO.OUT) # DB7
GPIO.setup(LED_ON, GPIO.OUT) # Backlight enable
# Initialise display
lcd_init()
# Toggle backlight off-on
GPIO.output(LED_ON, False)
time.sleep(1)
GPIO.output(LED_ON, True)
time.sleep(1)
# Send some centred test
lcd_byte(LCD_LINE_1, LCD_CMD)
lcd_string("--------------------",2)
lcd_byte(LCD_LINE_2, LCD_CMD)
lcd_string("Rasbperry Pi",2)
lcd_byte(LCD_LINE_3, LCD_CMD)
lcd_string("Model B",2)
lcd_byte(LCD_LINE_4, LCD_CMD)
lcd_string("--------------------",2)
time.sleep(3) # 3 second delay
string = ser.readline() // Here i added the code for the Serial connection
lcd_byte(LCD_LINE_1, LCD_CMD)
lcd_string(string,3) // lcd should display 'string'
lcd_byte(LCD_LINE_2, LCD_CMD)
lcd_string(".co.uk",3)
lcd_byte(LCD_LINE_3, LCD_CMD)
lcd_string("",2)
lcd_byte(LCD_LINE_4, LCD_CMD)
lcd_string("20x4 LCD Module Test",2)
time.sleep(20) # 20 second delay
# Blank display
lcd_byte(LCD_LINE_1, LCD_CMD)
lcd_string("",3)
lcd_byte(LCD_LINE_2, LCD_CMD)
lcd_string("",3)
lcd_byte(LCD_LINE_3, LCD_CMD)
lcd_string("",2)
lcd_byte(LCD_LINE_4, LCD_CMD)
lcd_string("",2)
time.sleep(3) # 3 second delay
# Turn off backlight
GPIO.output(LED_ON, False)
def lcd_init():
# Initialise display
lcd_byte(0x33,LCD_CMD)
lcd_byte(0x32,LCD_CMD)
lcd_byte(0x28,LCD_CMD)
lcd_byte(0x0C,LCD_CMD)
lcd_byte(0x06,LCD_CMD)
lcd_byte(0x01,LCD_CMD)
def lcd_string(message,style):
# Send string to display
# style=1 Left justified
# style=2 Centred
# style=3 Right justified
if style==1:
message = message.ljust(LCD_WIDTH," ")
elif style==2:
message = message.center(LCD_WIDTH," ")
elif style==3:
message = message.rjust(LCD_WIDTH," ")
for i in range(LCD_WIDTH):
lcd_byte(ord(message[i]),LCD_CHR)
def lcd_byte(bits, mode):
# Send byte to data pins
# bits = data
# mode = True for character
# False for command
GPIO.output(LCD_RS, mode) # RS
# High bits
GPIO.output(LCD_D4, False)
GPIO.output(LCD_D5, False)
GPIO.output(LCD_D6, False)
GPIO.output(LCD_D7, False)
if bits&0x10==0x10:
GPIO.output(LCD_D4, True)
if bits&0x20==0x20:
GPIO.output(LCD_D5, True)
if bits&0x40==0x40:
GPIO.output(LCD_D6, True)
if bits&0x80==0x80:
GPIO.output(LCD_D7, True)
# Toggle 'Enable' pin
time.sleep(E_DELAY)
GPIO.output(LCD_E, True)
time.sleep(E_PULSE)
GPIO.output(LCD_E, False)
time.sleep(E_DELAY)
# Low bits
GPIO.output(LCD_D4, False)
GPIO.output(LCD_D5, False)
GPIO.output(LCD_D6, False)
GPIO.output(LCD_D7, False)
if bits&0x01==0x01:
GPIO.output(LCD_D4, True)
if bits&0x02==0x02:
GPIO.output(LCD_D5, True)
if bits&0x04==0x04:
GPIO.output(LCD_D6, True)
if bits&0x08==0x08:
GPIO.output(LCD_D7, True)
# Toggle 'Enable' pin
time.sleep(E_DELAY)
GPIO.output(LCD_E, True)
time.sleep(E_PULSE)
GPIO.output(LCD_E, False)
time.sleep(E_DELAY)
if __name__ == '__main__':
main()
在这段代码中，我没有使用任何 while 循环。有了这个解决方案，它就可以工作了。但我希望我的 arduino 中的数据应该一直在显示器上更新。