Face Detection¶
Face detection has a wide range of application, we will learn how to do face detection in this tutorial.
Detecting Faces¶
Load KOI Extension: https://github.com/KittenBot/pxt-koi¶
Loading Extensions¶
Blocks for face detection:
Sample Program:¶
Program Flow¶
Download the program to the Micro:bit, the pixel on the Micro:bit 把程式下載到Microbit上,可以看到Microbit的點陣隨著人臉的移動而移動。
Mapping coordinates¶
We can use the map function to map a value to a new range.
Sample Code¶
Extension Version and Updates¶
There may be updates to extensions periodically, please refer to the following link to update/downgrade your extension.
FAQ¶
1: There is no reaction after pressing the buttons on the Micro:bit.¶
· A: This is because KOI has a longer boot time than Micro:bit. When the power is turned on, Micro:bit has already ran the code for KOI initialization before KOI is ready.
· Solution: Reset your Micro:bit after KOI has been turned on. (The trick is to let KOI power on completely before initialization.)
2: Does KOI work with 3V input?¶
· A: No, KOI only works with 5V.