I use the official Debian 9 desktop image. I can send data on uart4 with pyserial, but I can’t receive data. I have modified hw_intfc.conf
intfc:pwm0=off
intfc:pwm1=off
intfc:uart2=off
intfc:uart4=on
intfc:spi1=off
intfc:spi2=off
intfc:i2c2=off
intfc:i2c6=off
intfc:i2c7=off
Does anyone know the cause of this problem? I doubt it has something to do with some settings.