Component: USB Slave (Comms: USB)

Author	Matrix Ltd.
Version	1.1 (Release)
Category	Comms: USB

USB Slave component

Component to create and communicate using a generic USB communications profile. Has the ability to allow the device to be a slave to the PC. Compatible with simulation and USB enabled microcontroller devices (PIC/dsPIC).

Examples

The PIC based ECIOs or MIAC are good targets for USB as they do not have any additional configuration setting that need to be setup to allow the firmware to run correctly. For other targets you will have to setup the configuration correctly for your hardware to allow the USB to run correctly.

Basic Embedded Example

Here is an example file which waits for incoming data and then when valid data is received it displays this as a binary value onto the PortB pins before echoing back the data. USB Slave Simple Receive

USB Drivers

The example requires a device driver to function correctly. The driver can be generated by selecting the USB Slave component on the System panel, Looking down the list of properties in the properties window, selecting the Generate Driver property and switching the setting to Yes. This will place the driver .inf file into the same directory as the Flowcode fcfx project file is located.

Here is a signed version of the USB Slave device driver using the default VID/PID properties. The .inf driver file generated by Flowcode also requires some associated files which are not auto generated, these files can also be downloaded here.

File:USBSlave Driver.zip

The final driver files can be assembled by extracting the contents of the zip archive into a folder on your computer and adding the .inf file created by your Flowcode project. Running the correct executable for your PC type should then auto install the driver for you.

When the driver is installed correctly you will get your device showing up in the Windows device manager like this.

Basic Simulations Example

Here is an example file which is designed to run in simulation to communicate with the connected embedded device. The instance property will have to match the USB instance for the embedded device to allow the communications to work correctly. USB Slave Simulation The USB Slave instance is selected by selecting the USB slave component on the panel and setting the instance property.

When editing the USB Slave examples the slave service macro needs to match the setting in the USB Slave properties as shown below.

Slave Macro Setup

Slave Properties

Example console showing the data passed between the simulation and the embedded hardware.

The MIAC USB Slave and ECIO USB Slave Components are written based on the USB Slave component so these give a good example of what is possible using the component.

Downloadable macro reference

SendString

Adds a string of bytes onto the end of the outgoing data buffer.

Parameters

<- STRING Data

Data String To Send

This parameter may be returned back to the caller

BYTE Length

Max number of bytes to try and add to the outgoing buffer.

Return value

BYTE

GetString

Retreives a string of data from the incoming data buffer starting from location 0 and incrementing up to the NumBytes parameter.

Parameters

BYTE NumBytes

Specifies the maximum number of bytes to try and read.

Return value

STRING

RunSlaveService

Stalls the microcontroller and waits for an incoming message from the USB, when a message is received the macro defined in the USB Slave properties is automatically run. While the macro is running you can choose to send data back to the PC if you wish.

Parameters

This macro has no parameters

Return value

This call does not return a value

SendByte

Adds the byte onto the end of the outgoing data buffer.

Parameters

BYTE Data

Data byte to transmit to the host

Return value

BYTE

SendByteArray

Adds an array of bytes onto the end of the outgoing data buffer.

Parameters

<- BYTE Data

Data Bytes To Send

This parameter may be returned back to the caller

BYTE Length

Max number of bytes to try and add to the outgoing buffer.

Return value

BYTE

CheckRx

Called to check if there is any incoming data waiting to be received.

Returns the number of incoming data bytes.

Only needed when not running the slave service.

Parameters

This macro has no parameters

Return value

BYTE

GetByte

Retreives the byte at location Idx from the incoming data buffer.

Parameters

BYTE Idx

Specifies the location in the incoming buffer

Return value

BYTE

StopSlaveService

Allows the microcontroller to leave the stalled slave mode and resume its normal independant functionality. Must be called from within the slave service routine to work correctly.

Parameters

This macro has no parameters

Return value

This call does not return a value

Initialise

Starts up the USB communications and attempts to enumerate.

Returns 0 for a successful startup or 255 for a enumeration timeout.

Parameters

This macro has no parameters

Return value

BYTE

Simulation macro reference

This component does not contain any simulation macros

Property reference

Vendor ID

This property is of type Signed integer and can be referenced with the variable name vendor_ID.

USB VID

Product ID

This property is of type Signed integer and can be referenced with the variable name product_ID.

USB PID

Device Name

This property is of type Line of text and can be referenced with the variable name dev_name.

USB Device Name

Manufacturer

This property is of type Line of text and can be referenced with the variable name dev_manufacturer.

USB Manufacturer

Major Version

This property is of type Signed integer and can be referenced with the variable name major_version.

USB Major Version Number

Minor Version

This property is of type Signed integer and can be referenced with the variable name minor_version.

USB Minor Version Number

Enumeration Timeout

This property is of type True or false and can be referenced with the variable name enumeration_tout.

Specifies if the enumeration (Initialise function) can timeout if taking too long.

Country Code

This property is of type Fixed list of ints and can be referenced with the variable name country_code.

Country code used by some regional based USB devices

Maximum Current (mA)

This property is of type Signed integer and can be referenced with the variable name max_current.

Maximum amount of current the USB host will provide before shutting down the USB channel.

Slave Macro

This property is of type Line of text and can be referenced with the variable name slave_macro.

Flowcode macro to call while the slave service is enabled

Macro Parameters

This property is of type Fixed list of ints and can be referenced with the variable name slave_params.

Defines the parameters for the slave service macro allowing data from the host to be automatically passed into the macro.

Driver Directory

This property is of type Line of text and can be referenced with the variable name driver_directory.

Directory to save the generated device driver .inf file

Driver Filename

This property is of type Line of text and can be referenced with the variable name driver_filename.

Filename assigned to the USB device driver .inf file when generated.

Generate Driver

This property is of type True or false and can be referenced with the variable name gen_driver.

Generates a driver file when set to Yes, Automatically jumps back to No when complete.

Instance

This property is of type Fixed list of ints and can be referenced with the variable name Instance.

Hardware instance to communicate with any connected USB slave devices.

Timeout (ms)

This property is of type Unsigned integer and can be referenced with the variable name SimTimeout.

Simulation host to slave communications timeout in milliseconds

Label

This property is of type Line of text and can be referenced with the variable name label.

Text displayed on the I/O flasher comms component.