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USB API

Overview​

The USB API provides functions for interacting with USB devices. The API includes functions for checking if a USB device is connected, sending and receiving data over USB CDC, and more.

The header file for this API is part of os/MatrixOS.h and the implementation is in os/system/USB/.

Namespace: USB​

The USB namespace contains general USB functions.

MatrixOS::USB::Connected​

bool USB::Connected(void);

Checks if a USB device is connected.

Returns:

  • bool: true if a USB device is connected; false otherwise.

CDC​

The USB::CDC namespace provides functions for communication over USB as a virtual serial port (CDC). In the future this will likely migrate into a MatrixOS::Serial namespace with cross port support between USB, UART, BLE, etc.

MatrixOS::USB::CDC::Connected​

bool USB::CDC::Connected(void);

Checks if the USB CDC is connected.

Returns:

  • bool: true if the USB CDC is connected; false otherwise.

MatrixOS::USB::CDC::Available​

uint32_t USB::CDC::Available(void);

Returns the number of bytes available for reading.

Returns:

  • uint32_t: Number of bytes available.

MatrixOS::USB::CDC::Poll​

void USB::CDC::Poll(void);

Processes incoming and outgoing USB CDC data. This function should be called periodically.

MatrixOS::USB::CDC::Print​

void USB::CDC::Print(string str);

Sends a string over USB CDC without a newline.

Parameters:

  • str (string): The string to send.

MatrixOS::USB::CDC::Println​

void USB::CDC::Println(string str);

Sends a string over USB CDC with a newline appended.

Parameters:

  • str (string): The string to send.

MatrixOS::USB::CDC::Printf​

void USB::CDC::Printf(string format, ...);

Sends a formatted string over USB CDC.

Parameters:

  • format (string): The format string.
  • ...: Additional arguments for formatting.

MatrixOS::USB::CDC::VPrintf​

void USB::CDC::VPrintf(string format, va_list valst);

Sends a formatted string over USB CDC using a va_list.

Parameters:

  • format (string): The format string.
  • valst (va_list): A list of arguments for formatting.

MatrixOS::USB::CDC::Flush​

void USB::CDC::Flush(void);

Flushes the USB CDC output buffer.

MatrixOS::USB::CDC::Read​

int8_t USB::CDC::Read(void);

Reads a single byte from the USB CDC input buffer.

Returns:

  • int8_t: The byte read, or a negative value if no data is available.

MatrixOS::USB::CDC::ReadBytes​

uint32_t USB::CDC::ReadBytes(void* buffer, uint32_t length);

Reads multiple bytes from the USB CDC input buffer into the provided buffer.

Parameters:

  • buffer (void*): The buffer to store the read data.
  • length (uint32_t): The maximum number of bytes to read.

Returns:

  • uint32_t: The number of bytes actually read.

MatrixOS::USB::CDC::ReadString​

string USB::CDC::ReadString(void);

Reads a string from the USB CDC input buffer.

Returns:

  • string: The string read from the buffer.

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