Oak

🌳 An outdoor LoRa-GPS tracker with an E-Ink display 🔑

power 18650

wireless LoRa,

sensor GPS, E-Ink

mcu SAMD21G18

bom items 82

bom cost USD $78.93

vendors 6

completed July 2022

Why "Oak"?

Reflecting the strength and dependability of the mighty oak, ideal for a robust outdoor tracking device.

Sub-system

Mechanical sizes

Item	Height	Width	Depth	Weight
Waveshare 1.54inch E-Ink display module display	`48.0 mm`	`33.0 mm`	`mm`	`24 g`
HopeRF RFM95 LoRa module LoRa	`16 mm`	`16 mm`	`1.8 mm`	`2 g`
CDTop PA1010D GPS module LoRa	`10 mm`	`10 mm`	`6.8 mm`	`2.75 g`

Terminologies

Device - Oak, the entire electronics with embedded firmware and associated software
Local node - Current node that the user is holding, which is setup as a current node for LoRa peer-to-peer communication
Peer node - Peer node, another node that the device is setup as a destination for LoRa peer-to-peer communication
Haversine distance - Distance between the 2 nodes that has a GPS fix within 5 seconds of each other

User Stories

First-time user

As a first-time user, I want to configure the 2 nodes with addresses 0xAA and 0xBB so that they can communicate with each other via LoRa.

User

As a user, I want to know my current node does not have any GPS fix yet so that I know I need to wait for a possible GPS fix.

As a user, I want to see the current latitude-longitude so that I know my current location.

As a user, I want to see my latitude-longitude with a relative time ago so that I know my last GPS fix time.

As a user, I want to see the Haversine distance with the peer node so that I know how far away is the peer node.

As a user, I want to see the Haversine distance with a relative time ago so that I know how far away was the peer node when both nodes had a GPS fix.