Reference firmware for PixArt's PAT9130EW sensor and evaluation board. "Hello World" and "Library" contain the exact same files. Please import just one of the two into your mBed compiler as a new program and not as a library.

Revision:
0:5a34a4387fb0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Fri Apr 20 22:33:08 2018 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#569159b784f70feaa32ce226aaca896fb83452f7