Understanding The Echo

The Echo is designed to be a versatile and powerful platform for robotics and embedded projects. This section provides an overview of its key features and important operational considerations.

Layout

Key Features

The Echo boasts a comprehensive set of tools tailored for robotics applications, including:

• 6 DC Motor Drivers: For controlling a variety of brushed DC motors.

• 10 6V Servo Ports: Dedicated ports for precise control of up to ten 6V servos (driver I2C address: 0x40).

• 6 Degrees of Freedom (DoF) IMU: An integrated Inertial Measurement Unit for orientation and motion sensing.

• 14 Configurable GPIO Pins + 1 SDA & SCL Pin: Versatile General Purpose Input/Output pins for connecting sensors, actuators, and other peripherals.

• WiFi: For network communication and remote control.

• Bluetooth Low Energy (BLE): For energy-efficient short-range communication.

• ESP-NOW: For fast, connectionless communication between ESP devices.

Operational Limits

Like any electronic board, the Echo has specific operational limits that must be respected to prevent damage and ensure reliable performance. Adhering to these guidelines will help you maximize the Echo's capabilities within its intended design.

Motors

• Current and Voltage: Motor drivers are limited to a maximum current draw of 4.0A and a voltage range of 9-12V DC.

• PWM Channels: The Echo utilizes all of the ESP32-S3's built-in MCPWM (Motor Control PWM) drivers. This means that, unless explicitly reconfigured in your code, no additional MCPWM channels are available.

• VIN to Motor Drivers: The voltage supplied to the Echo's VIN (Voltage Input) terminal will directly power the motor drivers.

Servos

• Maximum Capacity: The Echo can power up to 10 servos concurrently, provided the total current draw does not exceed 10A.

• Fixed Voltage Output: The voltage supplied to the servo ports is a constant 6V and cannot be adjusted.

• Correct Connection: Always ensure servos are plugged in with the correct polarity and orientation to avoid damage.

IO (Input/Output)

• 5V Rail Current: The 5V rails on the I/O pins are limited to a maximum current draw of 1A.

• I2C Channels: The Echo utilizes one of the ESP32's two typical I2C channels for the integrated servo driver and IMU. The SDA and SCL pins found on the IO link to the same I2C bus.

VIN (Voltage Input)

• Operating Range: The Echo requires a minimum input voltage of 9V and a maximum of 12V to operate.

• Recommended Voltage: For general use, especially when concurrently operating motors, servos, and sensors, we highly recommend keeping the VIN between 9V and 12V. This range provides stability and helps mitigate the effects of voltage drops during high-current operations.

LEDs (Status Indicators)

The Echo features two helpful status LEDs, both conveniently located next to the VIN terminal:

• USB Power Indicator: When the Echo is powered via USB, one LED should immediately illuminate. This indicates that the board is receiving at least 3.3V of power, confirming it is ON and ready for programming.

• Full Power Indicator: When a battery or external power source greater than 9V is connected, the second LED will light up. This signifies that the Echo has sufficient power to operate all its components.

Important Notes:

• When the Echo is powered solely via USB, only the ESP32 and 3.3V logic devices should be used. Other components requiring higher power, such as motors and servos, should only be engaged when an adequate external power source is connected.

• Ensure all external devices are plugged in properly. Cross-wiring external devices such as sensors on the power lines can lead to catastrophic failures and possibly permanent damage.