Project Overview

We wanted to use the skills we learned in schematic, layout design, and part selection to implement computation, sensing , and power components. Ultimately, we came up with the Wearable Health Monitor which has all three functionalities and more! 

We would love to highlight the computation which is done with the ESP32-C3-MINI-1-N4 controlling the I2C communication to our display among other components. The user's heart rate is measured with the MAX 30102 Health sensor. This is all powered via a single 2000 mAh Lipo pouch cell that is protected with a battery management IC and recharged with a charger IC.  Lastly, the dual PCB design allows for compartmentalization of the circuit components. The top pcb contains all of the power components and the display, while the bottom pcb contains the computation and sensing components. 

We learned a lot about hardware integration and the troubles of actually designing your own PCB. We gained some extremeley useful hands-on skills as well as managing a project.

Bill of Materials

We reduced the cost significantly. <$50 for all components per board which would reduce with greater quantities.

Top PCB

(Top left):

Schematic of the battery management IC and required passives and circuitry which protects the Lipo pouch cell from overcurrenting.

(Top right):

Schematic of the USB-C connector to supply power to the charger IC. Additionally, there is a voltage regulator IC that steps down the voltage of the battery from 3.7V to 3.3V.

(Bottom left):

Full schematic view. There is a 6 pin connector which shares the same bus and power for the bottom pcb.

(Bottom right):

Schematic of the I2C display and necessary passives. The display tells the user their heart rate.

Bottom PCB

(Top left):

Schematic of the MAX 30102 Health sensor and required passives which does the heart rate sensing.

(Top right):

Schematic of the ESP32-C3-MINI-1-N4 along with the necessary passives to complete the circuitry that does the computing for the device as well as I2C. There is a voltage regulator IC and the necessary passives which steps down the 3.3V to 1.8V for the sensor. There are the boot and restart switches for the ESP32 as well as 2 MX style switches that are used by the user to controll the display. 

(Bottom left):

Full schematic view. There is a 6 pin connector which shares the same bus and power for the top pcb.

(Bottom right):

Schematic of the USB-C connector which we use to connect to the ESP32 for setting up the I2C communication. There is also an on/off switch.

Bring up and Progress