MicroPython Forum (Archive)

Hey,
Currently i am working on STM32F407discovery board. So i am programming USART6 ( tx pin PC6 and rx pin pc7) for asynchronous communication. So at present i am able to read values with the help of UART.read() but UNABLE to use UART.write() function.

Below is my code , kindly go through it and help me

import pyb
from pyb import Pin, UART
tx = pyb.Pin('PC6', Pin.OUT_PP, Pin.PULL_UP)
rx = pyb.Pin('PC7', Pin.OUT_PP, Pin.PULL_UP)

#UART6_9600baudrate_8data_NoPArity_1stopbit
uart = UART(6,9600,8,None,1)
buf = bytearray(20)

uart.readinto(buf)
uart.write(buf)

So in the above code i have created array of size 20. When i use uart.readinto(buf) the keys pressed on terminal2 (baudrate 9600) are stored in the buffer. But whenever, i try to print it on terminal using uart.write(buf) , it give some sort of garbage value. I have checked the baud rate of both UART6 and terminal it's same.

Also simple functions like uart.write('123') are also not working. I think their is some mistake in my steps because uart.read() is working properly. Wishing for quick response.

Thankyou

I'm not familiar with your board but in general it isn't necessary to initialise the pins to use a UART: creating the UART object does this for you. That said, I can't see why uart.write(b'123') won't work. Do you see garbage at the other end or nothing? If you have access to a scope or logic analyser it would be worth looking at the tx pin.

Yes, i was able to see garbage value. Now i have used TTL logic and its working fine. Thanks for help