Display
The display is made up of 25 LEDs arranged in a 5 × 5 grid. The LEDs are connected in a matrix, and the runtime software refreshes them very quickly so that they appear to stay on without flickering. The LED matrix can also be used to detect the surrounding light level. The software briefly switches some of the LED pins to input mode and measures how long the voltage takes to drop. This time is roughly related to the amount of light around the micro.
Sample Code
Program Link: https://makecode.microbit.org/_J0kPpyaF3LfM
Result: The micro:bit constantly checks the light level in a forever loop, displaying a heart icon if the level is less than 3 to indicate that it is dark. When you shine a flashlight on the device, the light level increases to 3 or higher, which triggers the else condition and causes the micro:bit to display a smiley face icon instead.
Specifications
| Item | details |
|---|---|
| Type | miniature surface mount red LED |
| Physical structure | 5x5 matrix |
| Electrical structure | 5x5 |
| Intensity control | Software controlled up to 255 steps |
| Sensing | ambient light estimation via software algorithm |
| Sensing Range | TBC, 10 levels from off to full on |
| Colour sensitivity | red centric, red is 700nm |