I am working on a project with arduino uno. I have to connect an spo2 sensor to it, but i am not sure which pins to use. http://learn.parallax.com/spo2-sensor-propeller-spin-demo shows the connections for the sensors. It's not the same one, but it has the same connection pairings. I have read that some people used the TX and RX pins, but I'm not too sure what to connect to what yet. Thank you for any help and advice.