From c26f53b958548bfd63eed9920a6ab4d3d2e57803 Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Thu, 5 Jun 2025 14:59:40 +0800 Subject: Add readme. --- README.txt | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) diff --git a/README.txt b/README.txt index d7ae631..cbc8c0a 100644 --- a/README.txt +++ b/README.txt @@ -1,4 +1,24 @@ -The carrier frequency of the radio module is 433MHz. +SMART HOME + +This is a collection of projects I'm currently working on to make our home +smarter. The project is in its early stages. This project considers efficiency +and environmental friendliness as part of the problem constraints. That means +'working' solutions aren't enough. They must be efficient. + +THE DOOR LOCK + +The door lock project aims to drive my door lock using a fingerprint sensor +module (FPM). In its current version, the front of the door has FPM connected +to an ATmega328P microcontroller. The back of the door has a servo connected to +another ATmega328P. Both modules have 2.4GHz NRF24L01+ RFMs connected to them. + +When the FPM authenticates a user, the MCU establishes a secure connection with +the back of the door, exchanges a session key, and transmits a lock/unlock +command to the servo. The wireless protocol allowed me to get it working with +modifying our old Japanese door lock. I wrote all the firmware and drivers of +this project from scratch. + +Although I designed this around RFM to learn more about RFM, the architecture +can be made more power-efficient if I toss the RFMs. I'm in the midst of making +these changes to the system. -Arduino Uno without sleep: 28.5 mA draw -Arduino Uno power down: 18.4 mA draw -- cgit v1.2.3