Cellular Comm Interface on UART (rm_cellular_comm_uart_aws)

Functions
CellularCommInterfaceError_t	RM_CELLULAR_COMM_UART_AWS_Open (rm_cellular_comm_uart_aws_instance_ctrl_t *p_instance_ctrl, CellularCommInterfaceReceiveCallback_t receive_callback, void *pUserData)
CellularCommInterfaceError_t	RM_CELLULAR_COMM_UART_AWS_Send (CellularCommInterfaceHandle_t commInterfaceHandle, const uint8_t *pData, uint32_t dataLength, uint32_t timeoutMilliseconds, uint32_t *pDataSentLength)
CellularCommInterfaceError_t	RM_CELLULAR_COMM_UART_AWS_Receive (CellularCommInterfaceHandle_t commInterfaceHandle, uint8_t *pBuffer, uint32_t bufferLength, uint32_t timeoutMilliseconds, uint32_t *pDataReceivedLength)
CellularCommInterfaceError_t	RM_CELLULAR_COMM_UART_AWS_Close (CellularCommInterfaceHandle_t commInterfaceHandle)
void	comm_uart_aws_callback (uart_callback_args_t *p_args)

Detailed Description

Middleware implementing the AWS Cellular Comm Interface for the FSP UART API.

Overview

See AWS documentation for how the Cellular Comm Interface works: https://www.freertos.org/Documentation/api-ref/cellular/cellular_porting.html#cellular_porting_comm_if

Configuration

Note

Using DTC with UART is recommended to reduce the number of interrupts in the system.

Build Time Configurations for rm_cellular_comm_uart_aws

The following build time configurations are defined in fsp_cfg/middleware/rm_cellular_comm_uart_aws_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	Selects if code for parameter checking is to be included in the build.
Receive Buffer	Size should be greater than zero	256	Temporary buffer for received bytes. When read function is called reamaining bytes will be read directly into buffer specified by read function argument.
Receive Transfer Size	Size should be greater than zero	512	The comm interface will break down UART reads into smaller read requests based on this number. For instance if this is set to 512 bytes then the interface will request 512 bytes at a time until the requested length is met or timeout. This is helpful for making use of DTC without having a long timeout period. AWS Cellular Interface Common->Comm Interface Receive Timeout is the timeout used for individual reads and should set accordingly based on this setting.

Configurations for Networking > Cellular Comm Interface on UART (rm_cellular_comm_uart_aws)

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_rm_cellular_comm_uart0	Module name.

Function Documentation

RM_CELLULAR_COMM_UART_AWS_Open()

CellularCommInterfaceError_t RM_CELLULAR_COMM_UART_AWS_Open	(	rm_cellular_comm_uart_aws_instance_ctrl_t *	p_instance_ctrl,
		CellularCommInterfaceReceiveCallback_t	receive_callback,
		void *	pUserData
	)

Implements open for CellularCommInterface_t

Parameters

[in]	receive_callback	Callback to call upon receiving data
[in]	pUserData	Pointer to user data to be passed through callback
[in]	p_instance_ctrl	Pointer to a rm_cellular_comm_uart_aws_instance_ctrl_t

Return values

IOT_COMM_INTERFACE_SUCCESS	Open succeeded
IOT_COMM_INTERFACE_BAD_PARAMETER	Bad parameter was passed in
IOT_COMM_INTERFACE_FAILURE	General failure
IOT_COMM_INTERFACE_DRIVER_ERROR	Lower level failure

RM_CELLULAR_COMM_UART_AWS_Send()

CellularCommInterfaceError_t RM_CELLULAR_COMM_UART_AWS_Send	(	CellularCommInterfaceHandle_t	commInterfaceHandle,
		const uint8_t *	pData,
		uint32_t	dataLength,
		uint32_t	timeoutMilliseconds,
		uint32_t *	pDataSentLength
	)

Implements send for CellularCommInterface_t. This function will block the calling thread until data is sent.

Parameters

[in]	commInterfaceHandle	CellularCommInterfaceHandle_t assigned in open
[in]	pData	Pointer to data to send
[in]	dataLength	Length of data to send
[in]	timeoutMilliseconds	Timeout in MS to wait for data to send
[in]	pDataSentLength	Actual length of data sent

Return values

IOT_COMM_INTERFACE_SUCCESS	Send succeeded
IOT_COMM_INTERFACE_BAD_PARAMETER	Bad parameter was passed in
IOT_COMM_INTERFACE_FAILURE	General failure
IOT_COMM_INTERFACE_DRIVER_ERROR	Lower level failure
IOT_COMM_INTERFACE_TIMEOUT	Send operation timed out

RM_CELLULAR_COMM_UART_AWS_Receive()

CellularCommInterfaceError_t RM_CELLULAR_COMM_UART_AWS_Receive	(	CellularCommInterfaceHandle_t	commInterfaceHandle,
		uint8_t *	pBuffer,
		uint32_t	bufferLength,
		uint32_t	timeoutMilliseconds,
		uint32_t *	pDataReceivedLength
	)

Implements receive for CellularCommInterface_t. This function will block the calling thread until data is received.

Parameters

[in]	commInterfaceHandle	CellularCommInterfaceHandle_t assigned in open
[in]	pBuffer	Pointer to buffer to receive to
[in]	bufferLength	Length of buffer
[in]	timeoutMilliseconds	Timeout in MS to wait for data reception
[in]	pDataReceivedLength	Actual length of data received

Return values

IOT_COMM_INTERFACE_SUCCESS	Receieve succeeded
IOT_COMM_INTERFACE_BAD_PARAMETER	Bad parameter was passed in
IOT_COMM_INTERFACE_FAILURE	General failure
IOT_COMM_INTERFACE_DRIVER_ERROR	Lower level failure

RM_CELLULAR_COMM_UART_AWS_Close()

CellularCommInterfaceError_t RM_CELLULAR_COMM_UART_AWS_Close

(

CellularCommInterfaceHandle_t

commInterfaceHandle

)

Implements close for CellularCommInterface_t

Parameters

[in]

commInterfaceHandle

CellularCommInterfaceHandle_t assigned in open

Return values

IOT_COMM_INTERFACE_SUCCESS	Close succeeded
IOT_COMM_INTERFACE_BAD_PARAMETER	Bad parameter was passed in
IOT_COMM_INTERFACE_FAILURE	General failure

comm_uart_aws_callback()

void comm_uart_aws_callback

(

uart_callback_args_t *

p_args

)

Callback for UART driver

Parameters

[in]

p_args

Arguments from UART RX/TX callback