Electronics and pricing

A project log for Minder

An open source smart watch built for anxiety and panic disorder.

Austin MarandosAustin Marandos 04/22/2018 at 01:100 Comments

The electronics used for the minder smart watch were sourced from various different suppliers.

1. OLED screen:  I choose a large 128X128 pixel OLED screen from the Australian electronics company Freetronics. I had used this screen in a previous smart watch project and it proved to be very versatile and reliable. (

2. RTC module: for the RTC I decided on using the DS3231. This is mainly due to the fact that the arduino that I used for the project was rated at 3.3 volts. (

3. Processor: For the main arduino board I used the Qduino mini V2 from Sparkfun. This board has a built in charging capability and also is very small allowing me to easily fit it into the 3D printed case.  (
4. Battery: I used a 3.7V 500 mah Lipo battery from Adafruit to power the entire watch. (

5.Heart rate sensor: For the heart rate sensor I used Sparkfun's MAX30105 board. This board also comes with other features other than the heart rate monitor such as; distance, particle detection and more. (

5.Vibrating motor: To alert the user of a panic attack and for haptic feedback I used a small vibrating motor from Polulo (

Image result for pololu vibrating motor

The overall price of the electronics:

ComponentPrice ($USD)Quantity
Qduino $29.951
Micro tactile buttons$0.504
Freetronics OLED screen$38.371
MAX30105 Sensor$12.951
Micro vibrating motor$3.491
Enameled copper wire$2.401
Micro SD card (for OLED)$111