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RL-ARM User's Guide (MDK v4)

RL-RTX RL-FlashFS RL-TCPnet RL-CAN RL-USB RL-USB for USB Device Applications RL-USB Device Library RL-USB Device Features RL-USB Device Software Stack RL-USB Device Functions RL-USB Device Source Files RL-USB Device Configuration Audio Device (ADC) Options Communication Device (CDC) - ACM Options Human Interface Device (HID) Options Mass Storage Device (MSC) Options Create USB Device Applications Create ADC Applications Create CDC ACM Applications Create HID Applications Create MSC Applications Create Composite Applications Test USB Device Applications Compliance Tests Test HID Client Application RL-USB for USB Host Applications RL-USB Host Library RL-USB Host Features RL-USB Host Software Stack RL-USB Host Functions RL-USB Host Source Files RL-USB Host Configuration Host Controller Driver Selection Host Controller Driver Configuration Host Class Driver Selection Create USB Host Applications Create USB Host HID Applications HID_Kbd Example Create USB Host MSC Applications Create USB Host Class Driver RL-USB Host Constants and Structures Error constants Speed constants Transaction Packet Type constants Transaction Error Type constants USB Request Block structure (USBH_URB) Endpoint structure (USBH_EP) Driver Capabilites structure (USBH_HCI_CAP) Device Class Instance structure (USBH_DCI) Host Controller Instance structure (USBH_HCI) Host Controller Driver structure (USBH_HCD) USB Concepts USB Transfer Rates USB Network Basic Communication Model USB Protocol Control Transfer Interrupt Transfer Isochronous Transfer Bulk Transfer Descriptors Device Configuration Device Descriptor Configuration Descriptor Interface Descriptor Endpoint Descriptor Device Qualifier Descriptor Example Programs Library Reference Appendix

Create ADC Applications

Create ADC Applications explains the steps to program a USB Device for audio streaming using the RL-USB Library. Audio applications control speakers, microphones, or other audio devices.

Include into the project and configure the following RL-USB Device Source Files:

  1. The library that matches the device core:
    USB_CM1.lib - for Cortex-M1 devices.
    USB_CM3.lib - for Cortex-M3 devices.
    USB_ARM_L.lib - for ARM7 or ARM9 devices.
  2. usb_config.c - to configure the USB system.
  3. usbd_device family.c(.h) - to configure the device hardware layer.
  4. usbd_user_adc.c - to adapt the code to the application needs.
  5. USBD_Demo.c - to initialize and connect the USB Device from main().

Applications can be created using existing µVision audio projects. The RL-USB audio examples have a simple function that receives an audio data stream from the host and sends it to a speaker.

  1. Copy all files from any folder \ARM\Boards\Vendor\BoardName\RL\USB\Device\Audio to a new folder and open the project *.uvproj with µVision. RTX projects are using the RTX-RTOS, whereas simple Audio projects work without an RTOS. However, the USB configuration does not differ.
  2. Open the file usb_config.c and configure the USB device with the Configuration Wizard.
  3. Enable USB Device and set the device characteristics.

    Config Audio Device

  4. Enable Class Support and Audio Device (ADC) and set the characteristics.

    Config Audio Device

  5. Optionally, adapt the source files usbd_device family.c that contain hardware dependent code and must be adapted to the USB controller.
  6. Modify the file usbd_user_adc.c to adapt the code to the application needs.


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