Tag Archives: diyha

Do It Yourself Home Automation System

06 Friday Dec 2019

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The building blocks of my do it yourself home automation system (DIYHA) consists of nine elements:

  1. Adafruit.io host for dashboards, graphs, control buttons, data storage, etc.
  2. Alexa interface through the Fauxmo server which emulates a Belkin switch
  3. Mosquitto MQTT broker/bridge server handles local messaging and the bridge to Adafruit.io
  4. Environment sensor servers measuring temperature, humidity, air pressure, gas concentration, air quality and light lux
  5. Motion sensor servers for security applications and to activate or deactivate lights
  6. Administration server to manage configurations and coordinate activities between servers
  7. Alarm servers are an integral part of the security system, e.g., intruder alerts and fire alarms
  8. Lighting control servers that are controlled by Alexa or motion sensor
  9. iOS application to provide a mobile administration tool

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.

IOT Digital Alarm Clock

23 Friday Oct 2015

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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.

IMG_1153

IOT Digital Alarm Clock Breadboard

Hardware features:

  1. ESP8266 ESP-1 Wi-Fi web server
  2. ATMega328pu 8 Mhz Real-time processor
  3. DS1307 real time clock
  4. OLED display user interface (status and controls)
  5. 7-segment LED digital time display
  6. Piezo buzzer and flashing LED for alarm
  7. Photo-resistor to measure room light
  8. I2C bus for communication
  9. 3.3 volt for all components

Software features:

  1. Sync time from NTP at power up
  2. Web form to manually set time
  3. Web form to control alarm clock settings
  4. Star Wars Imperial March alarm sound
  5. ATMega328 handles analog and digital devices

ESP-1 uses I2C to control all components

ESP-1 uses I2C to control all components

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.

ATMega328 handles all analog and digital devices.

ATMega328 handles all analog and digital devices.

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.

Simple web for served by the ESP-1

Simple web for served by the ESP-1

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.

Home Automation Motion Sensor

02 Wednesday Sep 2015

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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.

ATMega328 battery powered motion sensor

ATMega328 battery powered motion sensor

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:

ATMega328 Motion Sensor Project

ATMega328 Motion Sensor Project

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.