int incomingByte = 0; // for incoming serial data

void setup() {
  // put your setup code here, to run once:
  Serial.begin(300); // opens serial port, sets data rate to 300 bps
  pinMode(13, OUTPUT);
}

void loop() {
    // read the incoming byte:
    if(Serial.available()){
    // // say what you got:
    incomingByte = Serial.read();
    Serial.print(char(incomingByte));
    }


}
300
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
UART Debug
Bit 7
Idle Bit
Idle Bit
Idle Bit
SW7: Load | TX
SW8: Output Enable
TX
Output Enable
Idle Bit
OUTPUT
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Newline
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Start Bit
Idle Bit
Idle Bit
Idle Bit
Idle Bit
Bit 7
Idle Bit
Idle Bit
Idle Bit
Idle Bit
OUTPUT
Idle Bit
Idle Bit
Idle Bit
Idle Bit