Milestone 2.3

2.3: Concept Selection

Display Selection:

  • Our current selection for the display is a 1.3 inch OLED display panel.

  • It should fit perfectly in the provided space without causing the case to become too bulky.

  • It uses more energy than the E-Ink display would, but the quality of the display should help make the product seem more appealing to customers.

Battery Selection:

  • Our current selection for the battery is the 3.7 volt 2000 milliamp hour battery.

  • The capacity of the battery is fair, allowing phone charging of about 30-40% of the phone's battery. This shouldn't be too much of an issue as it's meant just to store some extra energy when the phone doesn't need it but the solar panel is in the conditions to supply it, and power some of the electronics such as the display.

  • We may need a voltage regulator to get the voltage from 3.7 to 5 volts to support USB protocol. We aren't positive if the charging chip does this, but are pretty sure it does.

  • Battery might be a little bulky when combined with the rest of the parts. We will keep this in mind when testing the first prototype, seeing how the case feels to be handled.

Chip Selection:

  • Our current selection for the chips are the Arduino ESP32 Nano and possibly the Lipo Rider Plus in addition to it.

  • The ESP32 Nano would be the main chip, being capable of running the display, optimizing charging, and has the capability to do even more as it has bluetooth and Wi-Fi.

  • The ESP32 Nano is also very small and thin, making it ideal for our product so we can keep the case fairly thin and light.

  • The ESP32 can only output 3.3 volts, but USB needs 5 volts, so either a voltage regulator is needed or possibly the Lipo Rider Plus chip could handle that, which is also small and would keep our case thin and light

GREEN CASE