Circuit Design

The electric circuit is analogous to human's neural system. The PIC32 microcontroller serves as the central nervous system of our RV ED-Splorer. The joystick, buttons, and IR sensor serve as the sensory nerve. On the other hand, the spotlight, RC servo motors, LED display matrix, and target LEDs serve as the actuators of our spotlight system.

Schematic Overview

Microcontroller: PIC32

The PIC32 MCU play as the brian of our RV Ed-Splorer. It processes input signal from hardware peripherals, make decisions, and drives control hardware peripherals to react to user interactions.

The PIC32 MCU is programmmed through SNAP Debugger and communicate with computer terminal by USB2Serial module.

LED Modules

Target LEDs

The Target LED module is composed of a 74HC138 3-8 decoder, 74HC04N inverter, and six white LEDs driven by 2N7000 MOSFETs. The decoder decodes 3 binary inputs to 8 output channels with inverted logic. The Inverter inverts the output from the decoder and drives the selected LED.

LED Display Matrix

The SPI input signal from PIC32 is fisrt amplified by 74HC244 buffer driver. Then the amplified SPI signal drives the two serial MAX7219 LED display modules.

PWM Modules

Spotlight Module

The duty cycle of SL_PWM_CMD controls the spotlight intensity. The two servo motors driven by PWM signals control the spotlight position in pitch and yaw directions.

Buzzer

The PWM signal form Buzzer_CMD pin control the frequency and amplitude of the buzzer by modulating PWM frequncy and duty cycle.

Time Indicator

The timeindicator is a simple RC servo motor driven by PWM signals.

User Input Modules

Push Buttons

When the button is pressed, this circuit drives the Brightbess UP/DN input to HIGH. The debouncing circuit ensures clean voltage transitions.

Joystick

The joystick convert the user input in X and Y directions to analog voltage signals. When the user presses the joystick, the JS_Button drives the input voltage high.