SLAA453A january   2011  – may 2023

 

  1.   1
  2. 1MSP430™ USB HID Windows API Programmer's Guide
  3. 2Introduction
  4. 3Implementation
    1. 3.1 Overview
    2. 3.2 File Organization
    3. 3.3 System Requirements
    4. 3.4 MSP430 USB API Stacks
    5. 3.5 How Windows Maps Physical USB HID Devices to the Host Application
    6. 3.6 Locating a Specific HID Device/Interface on the System and Opening It
    7. 3.7 Sending/Receiving Data
    8. 3.8 Detecting the Dynamic Connection/Disconnection of HID Devices
  5. 4Function Call Reference
    1. 4.1 Device Connection Management and Initialization Calls
      1. 4.1.1 VOID HID_Init(struct strHidDevice* pstrHidDevice)
      2. 4.1.2 DWORD HID_GetSerNums(WORD vid, WORD pid, struct strTrackSerialNumbers *serialNumList)
      3. 4.1.3 DWORD HID_GetNumOfInterfaces(WORD vid, WORD pid, DWORD numSerNums)
      4. 4.1.4 BYTE HID_Open(struct strHidDevice* pstrHidDevice, WORD vid, WORD pid, DWORD deviceIndex, char serialNumber[SERNUM_LEN], DWORD totalDevNum, DWORD totalSerNum)
      5. 4.1.5 BYTE HID_Close(struct strHidDevice* pstrHidDevice)
      6. 4.1.6 BYTE HID_GetVersionNumber(struct strHidDevice* pstrHidDevice, USHORT * VersionNumber)
    2. 4.2 Sending/Receiving Data
      1. 4.2.1 BYTE HID_WriteFile(struct strHidDevice* pstrHidDevice, BYTE* buffer, DWORD bufferSize, DWORD* bytesSent)
      2. 4.2.2 BYTE HID_ReadFile(struct strHidDevice* pStrHidDevice, BYTE* buffer, DWORD bufferSize, DWORD* bytesReturned)
    3. 4.3 Plug and Play Management
      1. 4.3.1 BYTE HID_RegisterForDeviceNotification(HWND hWnd, HDEVNOTIFY* diNotifyHandle)
      2. 4.3.2 BYTE HID_UnregisterForDeviceNotification(HDEVNOTIFY* diNotifyHandle)
      3. 4.3.3 BOOL IsDeviceAffected(struct strHidDevice* pstrHidDevice)
  6. 5Demo Application
  7. 6MSP430 USB Tool Suite
  8.   HID Interface Data Structure: strHidDevice
  9.   Format of Reports on HID-Datapipe Devices
  10.   C References
  11.   C Revision History

4.2.1 BYTE HID_WriteFile(struct strHidDevice* pstrHidDevice, BYTE* buffer, DWORD bufferSize, DWORD* bytesSent)

Description

Sends bufferSize bytes of data stored in buffer to the HID device designated by pstrHidDevice.

This function sends the data using HID reports as "packets". If any of the attempts to send a HID report times out, then the function returns HID_DEVICE_TRANSFER_TIMEOUT.

There is no inherent limit to the number of bytes that can be sent, other than the limitation imposed by bufferSize being a DWORD value. Packetization is handled automatically.

Parameters

Table 4-10 Parameters for HID_WriteFile()
strHidDevice* pstrHidDeviceThe structure containing the HID device information.
BYTE* bufferAn array of data to be sent
DWORD bufferSizeNumber of bytes to be sent, starting from address buffer.
DWORD bytesSentNumber of bytes actually sent (in the event of an error)
returnsHID_DEVICE_NOT_OPENED. The HID device failed to open.
HID_DEVICE_TRANSFER_TIMEOUT. A report request timed out.
HID_DEVICE_TRANSFER_FAILED. The transmission failed for unspecified reasons.
HID_DEVICE_SUCCESS. All the data was successfully sent.