Gy 521 Schematic Repack

If unused, these pins are left floating.

Pins 24 (XDA) and 23 (XCL) are broken out on some GY-521 versions (look for pads labeled SDA_AUX, SCL_AUX). These can connect an external magnetometer like the HMC5883L or a pressure sensor. In the standard schematic: gy 521 schematic