Wireless M-Bus Support#

sl_rail_sdk_wmbus_phy_software#

uint16_t sl_rail_sdk_wmbus_phy_software (uint8_t * buffer, uint8_t length, uint16_t buffer_length)

Runs the required software based phy processes on the buffer, depending on the mode.

The buffer must be big enough to hold the processed data. Currently, only T mode's Meter to Other requires software based crc and 3of6 encoding. For that, the buffer should be at 436B long for the longest packet. All other modes passes through this call without modifications sl_rail_sdk_wmbus_set_mode should be called before using this function.

Returns

• The length of the processed packet, that can be passed to the hardware, or 0 on error

sl_rail_sdk_wmbus_get_accessibility#

sl_rail_sdk_wmbus_accessibility_t sl_rail_sdk_wmbus_get_accessibility (void )

Get the current Wireless M-Bus accessibility settings.

Returns

• the current value

sl_rail_sdk_wmbus_set_accessibility#

void sl_rail_sdk_wmbus_set_accessibility (sl_rail_sdk_wmbus_accessibility_t new_wmbus_accessibility)

Set the current Wireless M-Bus accessibility settings.

sl_rail_sdk_wmbus_init#

void sl_rail_sdk_wmbus_init (void )

Initializes the MBUS and its mode.

sl_rail_sdk_wmbus_set_mode#

void sl_rail_sdk_wmbus_set_mode (sl_rail_sdk_wmbus_mode_t mode)

Sets the MBUS mode to use.

Currently only used to init and enable GPCRC for T mode Tx, and it also changes the time returned by sl_rail_sdk_wmbus_get_meter_limited_acc_rx_start().

sl_rail_sdk_wmbus_get_selected_mode#

sl_rail_sdk_wmbus_mode_t sl_rail_sdk_wmbus_get_selected_mode (void )

Gets the selected Wireless M-Bus mode.

Returns

• The selected mode of the Wireless M-Bus

sl_rail_sdk_wmbus_get_meter_limited_acc_rx_start#

uint32_t sl_rail_sdk_wmbus_get_meter_limited_acc_rx_start (bool slowMode)

Returns the delay after TX when RX should start in limited accessibility sl_rail_sdk_wmbus_set_mode should be called before using this function.

Returns

• The delay in microseconds

sl_rail_sdk_wmbus_get_meter_limited_acc_rx_stop#

uint32_t sl_rail_sdk_wmbus_get_meter_limited_acc_rx_stop (bool slowMode)

Returns the delay after TX when RX should stop in limited accessibility sl_rail_sdk_wmbus_set_mode should be called before using this function.

Returns

• The delay in microseconds

sl_rail_sdk_wmbus_frame_add_payload_int8#

uint8_t sl_rail_sdk_wmbus_frame_add_payload_int8 (uint8_t * buffer, sl_rail_sdk_wmbus_frame_dib_function_t dibFunction, uint8_t vib, int8_t value)

Helper function for building the payload of a Wireless M-Bus frame.

Adds an 8 bit integer (binary) data block to a buffer. Returns

• the number of bytes written into buffer

sl_rail_sdk_wmbus_frame_add_payload_int16#

uint8_t sl_rail_sdk_wmbus_frame_add_payload_int16 (uint8_t * buffer, sl_rail_sdk_wmbus_frame_dib_function_t dibFunction, uint8_t vib, int16_t value)

Helper function for building the payload of a Wireless M-Bus frame.

Adds a 16 bit integer (binary) data block to a buffer. Returns

• the number of bytes written into buffer

sl_rail_sdk_wmbus_frame_add_payload_int32#

uint8_t sl_rail_sdk_wmbus_frame_add_payload_int32 (uint8_t * buffer, sl_rail_sdk_wmbus_frame_dib_function_t dibFunction, uint8_t vib, int32_t value)

Helper function for building the payload of a Wireless M-Bus frame.

Adds a 32 bit integer (binary) data block to a buffer. Returns

• the number of bytes written into buffer

sl_rail_sdk_wmbus_frame_add_idle_filler#

uint16_t sl_rail_sdk_wmbus_frame_add_idle_filler (uint8_t * buffer, uint16_t fillerLength)

Helper function for building the payload of a Wireless M-Bus frame.

Adds filler bytes required before encryption Returns

• the number of bytes written into buffer

sl_rail_sdk_wmbus_frame_chars_to_mfield#

uint16_t sl_rail_sdk_wmbus_frame_chars_to_mfield (const char * manuf)

Helper function for converting uppercase ASCII letters to 2B manufacturer ID.

Returns

• the manufacturer id (or M-field) for M-Bus addressing

sl_rail_sdk_wmbus_frame_mfield_to_chars#

void sl_rail_sdk_wmbus_frame_mfield_to_chars (const uint16_t mfield, char * manuf)

Helper function for converting 2B manufacturer ID to 3 uppercase ASCII letter.

sl_rail_sdk_wmbus_frame_crypto5_init#

void sl_rail_sdk_wmbus_frame_crypto5_init (void )

Initializes crypto engine.

sl_rail_sdk_wmbus_frame_crypto5_set_key#

void sl_rail_sdk_wmbus_frame_crypto5_set_key (const uint8_t * newKey)

Sets key for mode5 encryption/decryption (AES-CBC)

sl_rail_sdk_wmbus_frame_crypto5_get_key#

void sl_rail_sdk_wmbus_frame_crypto5_get_key (uint8_t * key)

Returns key for mode5 encryption/decryption (AES-CBC)

sl_rail_sdk_wmbus_frame_crypto5_encrypt#

uint8_t sl_rail_sdk_wmbus_frame_crypto5_encrypt (uint8_t * input, uint8_t * output, uint8_t * iv, uint16_t length, uint8_t encryptedBlocks)

Encrypts blocks using mode5 (AES-CBC) encryption.

Also adds padding if needed, but the payload should include the 2B AES check (0x2f2f) in the beginning of the payload

Returns

• the number of blocks encoded. Output length is 16 times this value.

sl_rail_sdk_wmbus_frame_crypto5_decrypt#

void sl_rail_sdk_wmbus_frame_crypto5_decrypt (uint8_t * input, uint8_t * output, uint8_t * iv, uint16_t length)

Decrypts blocks using mode5 (AES-CBC) encryption.

sl_rail_sdk_wmbus_setup_frame#

uint16_t sl_rail_sdk_wmbus_setup_frame (uint8_t * buffer, uint8_t access_number, sl_rail_sdk_wmbus_accessibility_t accessibility, sl_rail_sdk_wmbus_device_type_t new_device_type, sl_rail_sdk_wmbus_sensor_data_t * sensors_data, bool periodic, bool encrypt)

Sets up a Wireless M-Bus frame.

Sets up a Wireless M-Bus frame by populating the provided buffer with the necessary information.

Returns

• The length of the assembled frame.