What do you do when you want to have an IoT LED strip but most of the world is in lockdown? You find spare hardware and DYI.
I present you the Poor man's IoT LED strip. Use it as an ambient light or whatever you want, really.
This is a quick and dirty implementation of a remote-controlled LED strip, using:
- Puck.js as a BLE button to toggle between LED effects (other Espruino devices may also work).
- Raspberry Pi Zero W as the receiver of the commands (other Raspberry Pi models with BLE capabilities may also work). The RPi runs the hyperion (ambilight software) to control the LED strip.
- WS2801 LED strip connected to the Rpi Zero W to display the effects (any LEDs supported by hyperion will work).
Communication occurs using BLE Advertising.
When the he Puck.js program starts, it sets its Bluetooth module to sleep. As soon as the button is pressed, the Bluetooth module is woken and will be put to sleep after a reasonable time of inactivity (15 seconds) - this is done to save battery. As soon as the Bluetooth module is awake, the code goes into 'Editing' mode (which will revert to 'Idle' mode after a 5 seconds of inactivity). Once 'Editing' mode is activated, every button press will advertise a 'button press' event using BLE capabilities, including the value of the current number of button presses, and will also increase that counter by 1.
The various LEDs indicate the different states of the button:
- The blue LED will be turned on for as long as the Bluetooth module is kept awake, as soon as it turns off, it means that the Bluetooth module is put to sleep.
- The green LED will be turned on when the button goes into 'Editing' mode, and it'll turn off as soon as the button goes back to 'Idle' mode.
- The red LED will be turned on when a button press is registered.
When the RPi receiver is started, it connects to the Hyperion server (the address and port can be configured), and will also start listening for BLE advertising events. When an event is received, it checks if the UUID matches the Puck.js one, and if so, it checks to see if the payload includes the count of button presses, if that's found, it uses the hyperion-client package to display the next effect using the LED strip.
By default, the LEDs will iterate through a list of hyperion effects, then a list of colors, and then it'll turn off (changes on every button press).
To run the button, use your computer to run the Espruino Web IDE and flash the code located in peripheral-button/button.js to your Puck.JS device.
To run the receiver, ensure the hyperion server is ran on system startup as a service. Then navigate to remote-receiver and run sudo npm start (sudo because otherwise you won't be able to use Bluetooth), and voilà.
This assumes hyperion is correctly installed and configured in the Raspberry Pi Zero W. This assumes node.js and npm is correctly installed in the Raspberry Pi Zero W. This also assumes a recent version of the Puck.js firmware is installed in the Puck.js device.