A lamp connected over the internet flashes colors based on notifications on a user’s phone (android). Hardware used: Raspberry Pi 3 Model B. Cloud service used: Ubidots.
The root directory contains an android studio project /android_LampNot and a python script /raspberry_pi/rasp_pi.py for Raspberry Pi. APK file is also available in the root directory.
The project was implemented using a Raspberry Pi 3 Model B. To flash colors, RGB LEDs were controlled using software PWM. Ubidots cloud service is used for message communication. Since Ubidots supports the MQTT protocol, the Raspberry Pi script uses the same to subscribe to the Ubidots broker.
The Ubidots cloud service allows for the creation of Devices and Variables. Variables are entities that hold data in a particular Device. To control colors being flashed, the android app updates values of these variables as and when notifications are received/cleared. Since the Raspberry Pi script subscribes to the Ubidots broker, changes in these variables are detected as and when they are published by the broker. Thus obviating the need to repeatedly use GET requests to detect changes in variable values.
The following fields need to be modified in the Raspberry Pi python Script:
pinRed = 7
pinGreen = 11
pinBlue = 13
These fields indicate the physical pins of the Raspberry Pi to which the RGB LEB terminals are connected
DEVICE_NAME = 'lamp_not'
VARIABLE_NAME = 'lamp'
TOKEN = 'A1E-vL7sdanfs7NyRyNZ2COokUvxsWqIJkGE2Nb0wVqABJ1N'
To get the above three fields:
- Sign-in to Ubidots
- Create a Device
- Create a Variable in the device you just created
For Example, consider a Device named lamp_not and a variable lamp in it as shown in the screenshots below:
The Token can be found by clicking your username in the upper-right corner and selecting API Credentials option.
Similarly, authentication details need to be entered in the android app too.
Notification access needs to be enabled for proper functioning. Select the ENABLE / DISABLE option in the main screen to do this.