Component: RF ISM (EB063, MRF49XA) (Wireless)

Author	Matrix Ltd.
Version	1.1 (Release)
Category	Wireless

RF ISM (EB063, MRF49XA) component

A simple RF-ISM communications module based on the Microchip Alpha MRF49XA device. Also available in the form of the EB063 RF E-block.

Examples

The example attempts to send and receive data from a remote board. You will need two RF modules to allow the communications to work.

The example can be used to drive both ends of the RF communications as it will send out data but also print out any data received onto the LCD. Pins RA0 and RA1 can be used for diagnostics on the program. RF Example

Downloadable macro reference

SetSyncPattern

Allows the sync pattern to be modified during runtime to allow for switching between several different RF connections.

Parameters

BYTE Mode

Switches on or off the extended sync functionality

BYTE Pattern

The bit pattern used for the standard sync mode

Return value

This call does not return a value

ReceiveByte

Puts the RF module in data mode and attempts to receive a single byte from the RF connection. Only packets containing a single data byte will be accepted.

Parameters

BYTE Timeout

Specifies how many milliseconds to wait for valid data before returning.

Return value

BYTE

SendString

Puts the RF module in data mode and transmits a packet containing the data string through the RF connection.

A packet consists of Sync information, Data and Checksum.

Parameters

STRING Data

Return value

This call does not return a value

TXTune

Used to specify and adjust the RF transmitter properties during runtime.

Parameters

BYTE Deviation

Specifies the transmit FSK frequency deviation - Range 0 - 15

BYTE Power

Specifies the transmitter power - Range 0 - 7

Return value

This call does not return a value

RXTune

Used to specify and adjust the RF receiver properties during runtime.

Parameters

BYTE Bandwidth

Specifies the Rx bandwidth - Range 1- 6

BYTE Gain

Specifies the Rx gain - Range 0 - 3

BYTE Threshold

Specifies the Rx signal to noise threshold - Range 0 - 5

Return value

This call does not return a value

SetBufferData

Allows a value to be loaded into the transmit buffer,

Parameters

BYTE Index

The current location in the transmit buffer starting from 0

BYTE Data

The data value to pass

Return value

This call does not return a value

UpdateCenterFrequency

Allows the RF center frequency to be adjusted during runtime to allow multiple RF channels to be scanned or multiplexed.

Parameters

UINT Frequency

Specifies the new center frequency value - Range 96 - 3903

Return value

This call does not return a value

FSKWrite

Writes to the FSK (frequency shift key) data pin.

Parameters

BYTE State

Return value

This call does not return a value

GetDataCount

Returns the number of bytes in the received data buffer.

Parameters

This macro has no parameters

Return value

BYTE

SendBuffer

Sends the contents of the transmit buffer.

Parameters

BYTE Count

Specifies how many bytes to transfer from the transmit buffer

Return value

This call does not return a value

SendByte

Puts the RF module in data mode and transmits a packet containing a single data byte through the RF connection.

A packet consists of Sync information, Data and Checksum.

Parameters

BYTE Data

Return value

This call does not return a value

ActivateTXMode

Enables the transmitter interface, allowing data to be sent.

The receiver interface is automatically disabled.

Parameters

This macro has no parameters

Return value

This call does not return a value

SetDataRate

Allows the RF data rate to be adjusted during runtime.

Parameters

BYTE Rate

Specifies the new data rate

Return value

This call does not return a value

ActivateRXMode

Enables the receiver interface, allowing data to be received.

The transmitter interface is automatically disabled.

Parameters

This macro has no parameters

Return value

This call does not return a value

FSKRead

Reads the FSK (frequency shift key) data pin.

Parameters

This macro has no parameters

Return value

BYTE

ReadRXSignalStrength

Returns the current received signal strength.

Parameters

This macro has no parameters

Return value

BYTE

Uninitialise

Powers down the RF module. The module must be re-initialised before it can be used again.

Parameters

This macro has no parameters

Return value

This call does not return a value

CheckBuffer

Checks for incoming data for a specific period of time.

Returns a value greater then 250 to indicate a failure.

Returns the length of the incoming data buffer to indicate success.

Parameters

BYTE Timeout

Time to wait before returning no data available

Return value

BYTE

GetBufferData

Returns a value from the incoming receive data buffer.

Parameters

BYTE Index

Specifies which position in the buffer to read data from

Return value

BYTE

ReceiveString

Puts the RF module in data mode and attempts to receive a string of bytes from the RF connection.

Parameters

BYTE Length

Specifies the maximum number of bytes to try and receive

BYTE Timeout

Specifies how many milliseconds to wait for valid data before returning.

Return value

STRING

Initialise

Starts up and configures the RF module ready for use.

The macro will return a value greater then 0 if the module has been started correctly, otherwise the macro will return a 0.

Parameters

This macro has no parameters

Return value

UINT

Simulation macro reference

This component does not contain any simulation macros

Property reference

Module Frequency

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

Module frequency - must be matched with the specific RF transciever being used.

Center Frequency (96-3903)

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

Specifies the default RF center frequency

Center Frequency (MHz)

This property is of type Floating point and can be referenced with the variable name cent_freq_cal.

Calculation to work out the approx actual frequency

Data Mode

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

Specifies if the module will send data packets (Byte) or FSK bits (Bit)

Data Buffer Size (Max)

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

Maximum number of bytes that can be loaded into a single data packet

Rate Divider 1

This property is of type Fixed list of ints and can be referenced with the variable name data_div1.

Data rate prescaler 1 - Coarse control

Rate Divider 2 (0-127)

This property is of type Signed integer and can be referenced with the variable name data_div2.

Data rate prescaler 2 - Fine control

Max Throughput (Kb/s)

This property is of type Floating point and can be referenced with the variable name baud_rate.

Calculated max data throughput if the data is 100% active

Data Rate Value

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

Actual default value passed to the data rate control

Sync Pattern

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

Default sync pattern used by the standard sync in byte data mode.

Extended Sync

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

Selects if an additional fixed sync byte is to be used.

Bandwidth

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

Controls the receiver bandwidth, the higher the value the bigger the datarate that can be acheived but the fewer channels that can co-exist

Gain

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

Controls the receiver gain - the amount to amplify the incoming signal before processing

Threshold

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

The signal to noise threshold used to control the sensitivity

Bandwidth

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

Controls the transmitter bandwidth, i.e. the frequency either side of the center frequency to use for the RF communications

Power

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

The amount of power to use when transmitting

SPI Channel

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

SPI peripheral used to talk to the RF module.

FSEL Pin

This property is of type Single digital pin and can be referenced with the variable name fsel_pin.

RF Mode selection pin

MOSI Pin

This property is of type Single digital pin and can be referenced with the variable name mosi_pin.

SPI Data Out pin - Master Out Slave In

MISO Pin

This property is of type Single digital pin and can be referenced with the variable name miso_pin.

SPI Data In pin - Master In Slave Out

SCK Pin

This property is of type Single digital pin and can be referenced with the variable name sck_pin.

Serial clock pin

CS Pin

This property is of type Single digital pin and can be referenced with the variable name cs_pin.

Chip select pin

Label

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

Label used to help identify the component on the panel.