/*
 * Arduino code for 8 pin analyzer
 * Due/Pro Micro can be Serial.begin(0); 
*/

void setup() {
  Serial.begin(0); // <-- Add required speed like 2000000
  while (!Serial) ;
  Serial.println("Connected");
}

void loop() { 
  Serial.write(PIND);
}

------------------------------------------------------------------

/*
 * Run sigrok-cli
 */
sigrok-cli -i /dev/cu.usbmodem411 -I binary -O ascii --continuous 

Can add more params like '--config samplerate=9600' <--- set the speed

------------------------------------------------------------------

Dump raw data and import it into PulseView https://sigrok.org/wiki/PulseView

dd if=/dev/cu.usbmodem411 of=./raw bs=1 count=1m

The above can be achieved by counting 0-255

Broken USB, homeless, no more testing... :( Lewisham Council making me sleep rough