Presence Light
Project Reason:
I have thought of this project, because coworkers walk 100 meters shaking the whole building just to see that the guy(coworker) behind me is not in his seat.
So i thought: "Why not make something, where he(guy behind me) can signal his presence.
I will create the project in parts or sub-projects:
LoRa Sender and Receiver with Dormant and RTC Alarm (RP2040)
This project focuses on the DORMANT mode of the RP2040. Furthermore the SX1278 is used to establish an encrypted communication between a sender and a receiver device. While saving energy through the DORMANT mode is the essential topic here, the GPIO-Wakeup(sender) and the RTC-Wakeup(receiver) are the key to save power but also be able to communicate.
Status:
Done
12.02.2025
Using Low Power E-Ink Display on Sender and Receiver to indicate the presence
To minimize the drawn current during the standby phases, instead of LED´s E-INK displays are used for indicating the current state. This sub-project takes the previous code from the first sub-project and adds the libraries and code for the E-INK display. Moreover the hardware got more compact with minor additions to make it work and prepare it for printed housing later on.
Status:
Done
12.07.2025
Powering everything through a battery
The device should be able to be charged and also indicate low battery voltage. For that reason, I designed a simple charging management board with a power path for a Lithium-Ion battery. Furthermore there will be an over- and undervoltage protection as well as an overcurrent protection to ensure a long battery life.
Status:
Done
05.01.2026
Printing a housing for the complete device and function tests
This part will talk about the design of the 3d-printed housing for the presence light as well as the whole assembled device. I will conclude this project with a some tests and finalize it with my thoughts.
Status:
In Progress
03.02.2026
