Introduction
This board can be a cool clock, a timer, a Lucky Turntable Game, a wearable ornament, and an interactive colored pendant. With a micro:bit main board, this 24 RGB LEDs circular expansion board changes to an exquisite creator's piece. You can turn it into a tomato timer via the onboard buzzer, and turn it into a colorful music spectrometer through the onboard microphone; There are two external ports P0, P1 in reserve, so you can get more ways to play by connecting a large number of boson and gravity sensors. With different paper-cuts and acrylics, you can put on a variety of new clothes for the expansion board. For example, put on red Chinese knot for it in Chinese New Year, put on the cartoon face for it at Children's Day, put on the snow or Christmas tree for it at Christmas......
Features
- Support USB interface power supply and direct use of power-bank power supply or USB computer power supply.
- Support PH2.0 interface power supply and the battery box or lithium battery power supply are both OK.
- 24 RGB single-line lights, 16 million colors free mixing
- Makecode graphical programming
- Onboard microphone and buzzer
- Leaded out P0 and P1 interfaces, and distribute with the connection line, support the boson expansion modules.
- Ultra-thin volume,more suitable for wearable and strap applications.
Specification
- Supply Voltage:3.5~5V
- WS2812 Single-line RGB LEDs x 24
- Onboard buzzer x 1
- Onboard microphone x 1
- Number of interfaces: IO expansion board(P0,P1)x2, PH2.0 Power Interface x1, USB power Interface x1
Board Overview
Note: After uploading the micro: bit program you need to connect the USB cable to the expansion board for power, You can also use 3.5-5.0 V power supply to power from the expansion board battery!
Tutorial
Makecode Tutorial Examples
- Click and enter the graphic programming: https://makecode.microbit.org/
- Preparation work, add the neopixel software package, in other words, loading the lamp ring library; the steps are as follows.
Rotated Circular Light
Click and enter the graphic programming:The Graphic Programming of Rotated Circular Light
'''Effect:''' The 9 RGB LEDs display 9 colors (gradients), and then on the lamp ring the nine RGB LEDs display the 9 colors in a continuous loop just like a waterfall light.
Light up 9 LEDs from the No. 0 LED
Modify to solid color rotation effect
Click and enter the graphic programming：Yellow Rotating Circular Light 
Modify the color behind the show color to get other solid color rotation effects.
Sound Control Circular Light
Click and enter the graphic programming: The Graphical Programming of Voice Control Circular Light
'''Effect:''' Light up 24 RGB LEDs in sequence according to the size of the detected sound, forming a gradual pulsating light ring.
By modifying the "Map" to change the relationship between sound intensity and the number of alight leds. 0300 represents the range of sound; 023 represents 24 RGB LEDs.
Control the Circular Light via Key A, B
Click and enter the graphic programming: Control the Annular Light via Key A, B
'''Effect:''' Turn on the power, then 24 RGB LEDs display some colors randomly in the beginning. When key A is pressed, executing the waterfall light mode once; When B is pressed, the circular light refreshes the color in every 20ms, and there are 7 colors at all.
RGB LEDs display color randomly when power on.
When key A is pressed, two-way waterfall light is started, that is, forward, reverse simultaneously.
When key B is pressed, the circular light is refreshed in every 20 ms.
Breathing Light
Click and enter the graphic programming:Breathing Light
'''Effect:''' 24 RGB LEDs light up red at the same time, the brightness changes from weak to strong in loop, like breathing.
Tomato Timer
The Pomodoro technique is a simple time management method. Essentially, it is to set a 25-minute work period and do only one thing in this period. So this is a 25 mins timer.
Click and enter the graphic programming:Tomato Timer
'''Effect:''' Press key A to start the program and light a LED on the main board in every minute. When all LEDs are on, the buzzer beeps; When key B is pressed, stops the buzzer and stops timing. The circular light refreshes the color in every second.
Execution Process: Firstly, define some variables. Such as "X", "Y", "pressed", "minutes". Where "X" and "Y" are the LED dot matrix coordinates of the micro:bit board.
Turn on the leds
Set Time Minutes<25;minutes 1; When minutes=25, the buzzer rings;
Set the effect of circular light When key A is pressed, start the circular light program; refresh the color in every second.
Calculation formula for the time interval between each RGB LED: 6000ms (1min) / 24 (24 RGB LEDs) / 60 (repeat 60 times) ≈41ms.
FAQ
Q: Why sometimes the light is partially lighted/ the brightness is low when the sample code is uploaded? A: The light ring requires a high power supply. So you need to connect the USB cable or the external battery to power port(USB/ external battery) of the expansion board.