Palm

🌴 Outdoor BLE-connected UV sensor keychain 🗝

power LiPO
wireless BLE
sensor UV Index
mcu nRF52
battery life 5 days
bom items 13
bom cost USD $50.47
vendors 4
completed July 2019

Mechanical sizes

Item Height Width Depth Weight
Adafruit Bluefruit nRF52 Feather 51 mm 23 mm 8 mm 5.7 g
Adafruit UV Sensor VEML6075 17.0 mm 15.3 mm 2.9 mm 0.8 g
LiPo battery 380mAh at 3.7V 37 mm 19 mm 8 mm

User Stories

User


As a user, I want to power ON the device so that it can measure the UV Index periodically.

As a user, I want to power OFF the device so that it can power down completely to save battery consumption.

As a user, I want to switch ON the wireless BLE so that it can transmit the data to another BLE device.

As a user, I want to switch OFF the wireless BLE so that it can stop transmitting the data to another BLE device.

As a user, I want to view the changing colors of the on-board RGB LED so that I know the current range of UV Index.

As a user, I want to view the numerical values of the UV Index and battery level data on another BLE device so that I know those values accurately.

As a user, I want to hang the entire keychain through the M6 drill hole so that I can be hands-free when outdoors.

State Machine

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State Machine