Night light dimmer
 

Jerry Komor 

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 Purpose of this project came about cause of couple cheep Chinese webcams that I have in one garage and one looking at the driveway randomly hanging and not responding. Its very annoying of not being able to see whats happening when I'm at work and cant get to those cameras so I figured I'll build a web controlled couple relays and either punch a port through the router or get to home LAN via VPN and reboot those devices and the simplest way would be to use NodeMCU chip.
Other part as the device would be mostly just sitting there and waiting for connections, and as I'm working in garage quite often or like to find temperature why not add couple temperature sensors and monitor temperature inside the garage and in front of the house.
For the garage decided to use DHT sensor as it gives temperature and humidity, I did not cared to much so I used DHT11 which has +/-2' variance, not a great issue but if I decide I can switch it for DHT22 which has greater accuracy. With outside temperature I decided to use LM35 sensor as I wanted to use the analog port on the NodeMCU and have extra pins free maybe for something else later on. One other thing I did add to this project was light sensor as I had been told I sometimes I leave the lights on not that I can shut it off but at least it can tell me that they are on. Simple LDR is used for that which leaves 2 digital pins free after connecting display over I2C port on 0.9 version of the NodeMCU. 1.0 version has couple extra pins not that they are necessary at the moment.  One thing in the future maybe I'll add routine to track time of how long the lights are on and watch for movement activity on PIR sensor and send me email status.

So far main code is done and working. Next thing to make is PCB with provision for 0.9 and 1.0 chips and maybe a base Node chip that I can solder onto the board.
Next update to the code I like to add large display clock and have it automatically sync with NTP server on the internet as it would be nice to have clock in garage and not worry that it gets reset cause of power failure and WiFi manager so I would not have to hard code WiFi credentials into the code which is most annoying. But for now current code is <here> will all necessary libraries <here>. You will have to remove the .txt extension form the code file and extract the library archive and install it into Arduino IDE


Hardware
Wanted to make the controller as simple as could be and to minimize on components. With the heart of the controller being NodeMCU which has all the necessary circuitry for CPU WiFi circuit and programmer interface. Additional components are hand full of passive parts and depending on drive it can vary from power transistors if so to relays. In our case we are using relays as the contacts are isolated from control circuit. We did add additional status LED to have visual indication when looking at the controller. Additional DHT11 and LM35 sensors provide temperature sensing and biased Light Dependant Resistor (LDR) resistor provides light sensing.

Software

Web interface / Software
Tried to make the web interface as simple and as possible and had divided into control and sensor status display.
Load status column is dynamic where the load channel button turns yellow when energized and goes gray when turned off. The controller is setup currently as true positive meaning that the output pin on controller is positive when energized.  Column On and Off are controlling state of the output. The code is written in a way that for all both buttons are showing all the time where as for individual load control channel On and Off buttons are alternatively shown. Thought was that there is no need to show the On button if the load is On. This can be changed in each table row output control. The IF statement controls how the load is shaded and also selects if On or Off buttons are shown. If there is no need to control shade of the load button cell nor controlling which button is shown by removing/ commenting the IF directive and un-commenting the 3 lines below it.




At the moment the display refreshes each time the load control button is clicked on or refreshed once every 15 seconds automatically. When connecting to the device, actual state of the output will be shown due to that there are status flags for each output and are used within the HTML code section.







 



 

 

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