from pyb import UART
import uos
uos.dupterm(None, 0) #slot 1 should be usb-vcp
# pyb.usb_mode('VCP+VCP+MSC')
uart = UART(4, 115200)
uart.init(115200, bits=8, parity=None, stop=1, timeout=2)
buf = bytearray(10)
nread = 99
def irq_fun(tmp):
nread = uart.readinto(buf,3)
print("Received {}: {}\n".format(nread, int(buf[0])))
uart.write(buf)
uartIRQ = uart.irq(trigger = UART.IRQ_RXIDLE, handler = irq_fun)
