hid_write method

int hid_write(Pointer<hid_device> dev, Pointer<UnsignedChar> data, int length)

@brief Write an Output report to a HID device.

The first byte of @p data[] must contain the Report ID. For devices which only support a single report, this must be set to 0x0. The remaining bytes contain the report data. Since the Report ID is mandatory, calls to hid_write() will always contain one more byte than the report contains. For example, if a hid report is 16 bytes long, 17 bytes must be passed to hid_write(), the Report ID (or 0x0, for devices with a single report), followed by the report data (16 bytes). In this example, the length passed in would be 17.

hid_write() will send the data on the first OUT endpoint, if one exists. If it does not, it will send the data through the Control Endpoint (Endpoint 0).

@ingroup API @param dev A device handle returned from hid_open(). @param data The data to send, including the report number as the first byte. @param length The length in bytes of the data to send.

@returns This function returns the actual number of bytes written and -1 on error. Call hid_error(dev) to get the failure reason.

Implementation

int hid_write(
  ffi.Pointer<hid_device> dev,
  ffi.Pointer<ffi.UnsignedChar> data,
  int length,
) {
  return _hid_write(
    dev,
    data,
    length,
  );
}