How to Use 96Boards Consumer Edition - Low Speed Expansion: Examples, Pinouts, and Specs

The 96Boards Consumer Edition - Low Speed Expansion board is a versatile add-on designed for 96Boards-compliant systems. It provides additional GPIO, I2C, SPI, and UART interfaces, enabling users to connect a wide range of peripherals and sensors. This expansion board is ideal for prototyping, IoT applications, robotics, and other projects requiring extended connectivity.

Common applications include:

• Connecting sensors (e.g., temperature, humidity, motion sensors)
• Driving actuators (e.g., motors, relays)
• Enabling communication with external devices via UART, SPI, or I2C
• Building IoT systems and smart devices

The 96Boards Consumer Edition - Low Speed Expansion board adheres to the 96Boards specification, ensuring compatibility with compliant systems. Below are the key technical details:

The Low Speed Expansion board features a 40-pin connector. Below is the pinout and description:

Note: The full pinout can be found in the official 96Boards documentation.

1. Connect the Expansion Board: Attach the Low Speed Expansion board to a 96Boards-compliant system via the 40-pin low-speed connector.
2. Power the System: Ensure the 96Boards system is powered via its standard power supply.
3. Connect Peripherals: Use the GPIO, I2C, SPI, or UART pins to connect sensors, actuators, or other peripherals.
4. Configure Voltage Levels: By default, the board operates at 1.8V logic levels. If your peripherals require 3.3V, use a level shifter or configure the board (if supported).

• Voltage Compatibility: Ensure all connected peripherals are compatible with the board's voltage levels (1.8V or 3.3V).
• Pin Multiplexing: Some pins may serve multiple functions (e.g., GPIO or UART). Refer to the 96Boards documentation to configure the desired functionality.
• Avoid Overloading: Do not exceed the current limits of the GPIO pins to prevent damage.
• Use Pull-Up Resistors: For I2C communication, ensure appropriate pull-up resistors are in place.

To connect an I2C sensor to the Low Speed Expansion board and read data using an Arduino UNO, follow these steps:

1. Connect the I2C sensor's SCL and SDA pins to the I2C0_SCL and I2C0_SDA pins on the expansion board.
2. Power the sensor using the 5V and GND pins on the expansion board.
3. Use the following Arduino code to read data from the sensor:

#include <Wire.h> // Include the Wire library for I2C communication

#define SENSOR_ADDRESS 0x40 // Replace with your sensor's I2C address

void setup() {
  Wire.begin(); // Initialize I2C communication
  Serial.begin(9600); // Start serial communication for debugging
}

void loop() {
  Wire.beginTransmission(SENSOR_ADDRESS); // Start communication with sensor
  Wire.write(0x00); // Replace with the register address to read from
  Wire.endTransmission();

  Wire.requestFrom(SENSOR_ADDRESS, 2); // Request 2 bytes of data
  if (Wire.available() == 2) {
    int data = Wire.read() << 8 | Wire.read(); // Combine two bytes into one value
    Serial.print("Sensor Data: ");
    Serial.println(data); // Print the sensor data to the serial monitor
  }

  delay(1000); // Wait for 1 second before the next reading
}

Note: Replace SENSOR_ADDRESS and register values with those specific to your sensor.

1. No Communication with Peripherals

   • Cause: Incorrect voltage levels or wiring.
   • Solution: Verify the voltage levels and ensure proper connections.

2. I2C Devices Not Detected

   • Cause: Missing pull-up resistors on the I2C lines.
   • Solution: Add 4.7kΩ pull-up resistors to the SCL and SDA lines.

3. GPIO Pins Not Responding

   • Cause: Incorrect pin configuration or multiplexing settings.
   • Solution: Check the pin multiplexing settings in the 96Boards documentation.

4. Overheating

   • Cause: Excessive current draw from peripherals.
   • Solution: Ensure connected devices do not exceed the current limits of the board.

Q: Can I use 5V logic peripherals with this board?
A: No, the board operates at 1.8V or 3.3V logic levels. Use a level shifter for 5V peripherals.

Q: How do I switch between UART and GPIO functionality?
A: Refer to the 96Boards documentation for instructions on configuring pin multiplexing.

Q: Is the board compatible with all 96Boards systems?
A: Yes, the Low Speed Expansion board is designed to be compatible with all 96Boards-compliant systems.

Q: Can I power external devices using the 5V pin?
A: Yes, but ensure the total current draw does not exceed the power supply's capacity.

For additional support, consult the official 96Boards documentation or community forums.