UART implementation inside the Adafruit Python library has methods to set up and start UART channels, load an appropriate device tree and to clean up. It does not provide actual UART read/write methods as they are already part of the Python module "pyserial." There is a need for a "pyserial" Python module installation to read/write on the UART channel. Run the following command:
sudo pip install pyserial
Connect pin "P9_24" (TX pin of UART1) to "P9_11" (RX pin of UART4) using a jumper wire. Type the following two programs in Cloud9, save them as UART1.py and UART4.py. Run UART4.py first. Then run UART1.py. You should see Hello World printed on the output window of program UART4.py.
This the code for UART1.py:
#!/usr/bin/python
import Adafruit_BBIO.UART as UART
import serial
import time
port = "/dev/ttyO1"
baudrate = 9600
write_str = "Hello World\n"
UART.setup("UART1")
ser1 = serial.Serial(port, baudrate)
ser1.close()
ser1.open()
if ser1.isOpen():
print(...
