System architecture
This article is intended for advanced users only.
The figure above shows a schematic overview of the OpsoroHAT electronics architecture. The board has the following features:
- ATmega328 microcontroller which communicates with the Raspberry Pi over SPI.
- A 16 channel servo controller (PCA9685) with beefy power traces.
- A Power MOSFET to enable or disable all servos.
- An I2S soundcard with a 5W mono class-D amplifier, to be used with a 4 ohm or 8 ohm speaker.
- A 12 channel capacitive touch controller (MPR121).
- A power connector for back-powering the Raspberry Pi. (No more cutting up USB cables!)
- Support for NeoPixel LEDs
- A I2C expansion header with signals translated to 5V logic, convenient for hooking up arduino-compatible I2C devices
- A 4-channel analog sensor input.
- HAT EEPROM.
- Protection circuitry: TVS diodes, reverse polarity protection, etc.