- /* Load the next byte from the USART transmit buffer into the USART */
- if (!(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
+ /* Load the next byte from the USART transmit buffer into the USART if transmit buffer space is available */
+ if (Serial_IsSendReady() && !(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))