Pan-Tilt HAT User Manual
Version: V1.0.0; Date: 2019.03.16
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HARDWARE
CONTROLLER
The PWN driver is PCA9685, an I2C-bus controlled 26-channel LED controller, 12-bit
resolution PWM output. Pan-Tilt HAT integrate TSL2581 on board. TSL2581 is a light
sensor, can be used to detect light and work with camera. TSL2581 use I2C interface as
well.
COMMUNICATION PROTOCOL
I2C-bus has one data line(SDA) and one clock line(SCL). When communicating, three
kinds of signals are product: Start signal, Stop signal and Answer signal.
Start signal:
SCL is High, SDA changes from High to Low, start to transmit data
Stop signal:
SCL is High, SDA changes from Low to High, stop transmitting
Answer signal:
The receiver will answer a Low plus to sender after receiving 8-Bit data
as ACK.
I2C WRITE DATA
