STM32 RS485 modbus通讯源程序，亲测有效

这个程序可以让stm32f103zet6和带485的触摸屏通讯吗，要不要改什么东西

Build target 'Target 1'
compiling main.c...
compiling stm32f10x_it.c...
assembling startup_stm32f10x_hd.s...
compiling stm32f10x_gpio.c...
compiling stm32f10x_rcc.c...
compiling misc.c...
compiling stm32f10x_exti.c...
compiling stm32f10x_tim.c...
compiling stm32f10x_usart.c...
compiling stm32f10x_iwdg.c...
compiling stm32f10x_wwdg.c...
compiling stm32f10x_bkp.c...
compiling stm32f10x_pwr.c...
compiling stm32f10x_adc.c...
compiling stm32f10x_dac.c...
compiling stm32f10x_dma.c...
compiling stm32f10x_rtc.c...
compiling system_stm32f10x.c...
compiling core_cm3.c...
compiling led.c...
compiling rs485.c...
APP\rs485\rs485.c(127): warning:  #940-D: missing return statement at end of non-void function "rs485_UartWrite"
  }
APP\rs485\rs485.c: 1 warning, 0 errors
compiling crc16.c...
compiling system.c...
compiling SysTick.c...
linking...
Program Size: Code=3340 RO-data=848 RW-data=36 ZI-data=1148  
FromELF: creating hex file...
".\Obj\Template.axf" - 0 Error(s), 1 Warning(s).
Build Time Elapsed:  00:00:11

这个怎么解决