Stability is the enemy of IMUs. The MPU-6050 is an analog-heavy device measuring tiny changes in capacitance (accelerometer) and Coriolis force (gyroscope). Power supply noise can easily translate into data noise.
The second most crucial aspect of the GY-521 schematic is the communication interface. The MPU-6050 communicates via I2C (Inter-Integrated Circuit), a protocol that requires the bus lines to be held high (idle state) via pull-up resistors. gy 521 schematic
Examining the schematic reveals several limitations: Stability is the enemy of IMUs
Some compact GY-521 boards omit XDA, XCL, ADO, and INT, exposing only VCC, GND, SCL, SDA. exposing only VCC