SparkFun Pulse Oximeter and Heart Rate Monitor Hookup Guide
Elias The Sparkiest 
Hardware Hookup
MFIO and RESET.
This board is an I²C based board and so we've included a Qwiic Connector. However, it isn't a "pure" Qwiic board as it requires two additional pins to be attached in order for it to function. However, you still don't need to solder if you have some of our IC hook with pigtail and in fact that's what I'll use for the following example. First, let's plug in our Qwiic Connector cable to either of the Qwiic connectors on the SparkFun Pulse Oximeter and Heart Rate Monitor.
Next we'll take the IC hooks and plug them into Redboard Qwiic into pins 5 and 4.
We'll then attach the claw side of the the IC hooks, the first in pin 5 to MFIO and the second plugged into pin 4 to RESET.
When we get to sensing your pulse and blood oxygen levels, it's important that when you place your finger onto the sensor that you place it lightly and with consistent pressure. You can try to do this without any support, but I found that a rubber band is a good place to start.
