BF533 UART communication

Hello,

I have an school project on making uart communication between two bf533, i need to send the interupt by pressing the switches (buttons) and on the otherside to make leds to glow, i tried few ways of making it but it doesnt work, if anyone has any tips or working code it would be really helpfull. i attached codes for receiver adn transmiter.trans.rarreceptie2.rar