Bill of Materials:
-Two Channel Relay.
Step 1: Step One
Connect DC Booster to Arduino.
-Connect ground to the negative "IN" on the DC booster.
-Connect 3V to the positive "IN" on the DC booster.
Step 2: Step 2. Connect Relay to DC Booster
Connect the DC booster to the Relay.
-Connect the DC booster "OUT" positive to the Relay.
-Connect the DC booster "OUT" negative to the TENS EMS pad.
Step 3: Step 3: Connect Relay to Arduino.
Connect Relay to Arduino.
You can control the Relay with Arduino Code.
Step 4: Step 4: Connect Flex Sensors and LED's to Arduino.
Connect all sensors and LED's to code.