wiringPi to transmit over UART in subscriber callback without sudo [closed]

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Hi,

I am trying to create a ROS node in which I have a subscriber to a /cmd_vel topic, and a callback function in which I transmit the cmd_vel data to a slave MCU over UART.

I am unable to use wiringPi serialPutchar(), or run any other C executable without directly invoking sudo. I have seen the other posts on this board, and have tried all of their suggestions to no avail.

Every time I get the warning "wiringPiSetup: Must be root. (Did you forget sudo?)".

Steps I have taken: - I have edited /etc/inittab and /boot/cmdline.txt - I have executed sudo usermod -a -G dialout pi - I have executed gpio export 15 out and gpio export 16 in - I have executed sudo chmod 777 /dev/ttyAMA0 - I call wiringPiSetup() in the first line of my code

Is it impossible to control any hardware on the PI without acting as sudo? How else can you write a ROS node to send something over the Pi's hardware UART?

Also, is transmitting over UART in a subscriber's callback function a bad practice?

Best,

Brett