I built a very loud alarm siren for my home automation system. Construction information is on Hackster.io with parts, code, etc.
The building blocks of my do it yourself home automation system (DIYHA) consists of nine elements:
Future posts will provide build instructions to create you own DIYHAS solution. The servers are all Raspberry Pi devices with applications written in Python 3 and the help from lots of great open source code. I’m planning to push all of my python source to github to coincide with posts.
I’ve started work on a new version of my alarm clock. I wanted to add a couple of improvements to the first version which was based on an ATMega328pu processor and NRF24 radio. This version would use an ESP-1 for both communication and standalone configuration. This became the first version of my DIY clock projects. Later versions are based on Raspberry Pis.
The OLED can be hidden and only needed at startup to determine the status of the system and to show the IP address of the device.
A simple web form is used to (a) manually set date and time; (b) set the alarm time; (c) enable the alarm clock and (d) sound a system alarm.
The video below demonstrates the basic features using the breadboard design.
The next step is to complete the software development and move everything to a protoboard and antique box.
This is a prototype of my battery powered PIR motion sensor unit that I have on my front porch. It has run for several months on 3 AA batteries. Larry gave me the idea to use the PIR output to drive a MOSFET power switch.
The ATMega328 and NRF24 radio are powered up by motion detected by the PIR sensor. In the setup() routine it determines which of the four outdoor sensor locations it has been installed in (front porch, back yard, etc.) by the 2 position DIP switch, configures the NRF24 radio (DIP determines mesh network parent and pipe addresses), sends a message to a mesh NRF24 router unit and then enters a null loop until it looses power (PIR goes low). I’ve used an Adafruit proto-board to build a more permanent version:
I’ve run this device for more than 3 months and it works great. My next prototype will use the same idea but replace the ATMega328 and NRF24 with an ESP-1 Wi-Fi client.