Palm

🌴 A BLE-connected outdoor 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

Downloads

Demo Code Schematic Layout ECAD KiCad files Gerber files Bill of Materials

Features

Read UV Index with the on-board sensor VEML6075 and the battery level
Display the UV Index color code with the on-board RGB LED
Power on/off the entire device with the on-board power switch
Start or stop BLE advertising with the on-board BLE switch
Connect via the USB cable to flash the firmware or charge the LiPo
Hang it like as keychain using the M6 drill hole
Display UV Index and Battery level as a GATT service and characteristic on a BLE client such as the iPhone or Web BLE on Chrome browser

Getting Started

Step 1

Wire up the hardware components with nRF52 Adafruit feather board, VEML6075 sensor board and LiPo battery. Turn on the switch for power and BLE.

Step 2

Flash the firmware onto the nRF52 board to display UV Index and battery level.

Step 3

See the UV and battery level values on the nRF Connect iPhone app

Maintenance

Flashing firmware: Plug in the USB cable into the USB connector
Charging the LiPo: Plug in the USB cable into the USB connector. Charging will have the yellow LED on.