modem.c File Reference

Implements functions for connecting to the cellular network, and sending/receiving packets. More...

#include <device.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "modem.h"
#include "strlib.h"
#include "extern.h"

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Functions
	CY_ISR_PROTO (Telit_isr_rx)
void	uart_string_reset ()
	Reset modem_received_buffer, clear RX buffer, and reset string index. More...
uint8	modem_startup (int *conn_attempts)
	Startup sequence to power on the modem, start modem components and prepare for sending/receiving messages over the network. More...
uint8	modem_shutdown ()
	Shutdown sequence to stop/power down modem components. More...
void	modem_start ()
	Initialize modem.
void	modem_stop ()
	Deinitialize modem.
uint8	at_write_command (char *uart_string, char *expected_response, uint32 uart_timeout)
	Write AT command to cell module. More...
uint8	modem_power_on ()
	Powers on the modem. More...
uint8	modem_power_off ()
	Powers off the modem. More...
uint8	modem_reset ()
	Resets the modem. More...
uint8	modem_setup ()
	Initialize configurations for the modem. More...
uint8	modem_connect ()
	Establish modem connection with internet. More...
uint8	modem_disconnect ()
	Close modem connection to network. More...
uint8	modem_check_network ()
	Network Registration Report. Function wrapper for AT+CREG command. More...
uint8	modem_get_meid (char *meid)
	Mobile Equipment Identifier. Function wrapper for AT::MEID command. More...
uint8	modem_check_signal_quality (int *rssi, int *fer)
	Signal Quality Check. Function wrapper for AT+CSQ command. More...
int	modem_get_socket_status ()
	Socket Status. Function wrapper for AT::SS command. More...
uint8	modem_set_flow_control (uint8 param)
	Set Flow Control. Set command controls the RS232 flow control behaviour. More...
uint8	modem_set_error_reports (uint8 param)
	Report Mobile Equipment Error. Set command enables/disables the report of result code. More...
uint8	modem_pdp_context_toggle (uint8 activate_pdp)
	Context Activation. Execution command is used to activate or deactivate the specified PDP context. More...
uint8	modem_socket_dial (char *socket_dial_str, char *endpoint, int port, int construct_new, int ssl_enabled)
	Opens a remote connection via socket. More...
uint8	modem_socket_close (int ssl_enabled)
	Closes the socket on the modem. More...
void	construct_generic_request (char *send_str, char *body, char *host, char *route, int port, char *method, char *connection_type, char *extra_headers, int extra_len, char *http_protocol)
	Constructs a generic HTTP request. More...
int	send_chunked_request (char *send_str, char *chunk, int chunk_len, char *send_cmd, char *ring_cmd, char *term_char)
	Breaks request string into packets and sends them. More...
int	read_response (char message[], char *recv_cmd, char *ring_cmd, uint8 get_response, int max_loops, int max_message_size)
	Reads a HTTP response with a chunked of fixed-length transfer encoding over multiple modem buffers. More...
uint8	modem_send_recv (char *send_str, char *response, uint8 get_response, int ssl_enabled)
	TODO. More...
	CY_ISR (Telit_isr_rx)

Variables
int	iter = 0
uint8	modem_state
uint8	lock_acquired = 0u
uint8	ready = 0u
uint16	uart_string_index = 0u
uint32	feed_id
char	modem_received_buffer [MODEM_BUFFER_LENGTH] = {'\0'}
char	request_chunk [CHUNK_SIZE] = {'\0'}
char *	modem_apn = "epc.tmobile.com"

Detailed Description

Implements functions for connecting to the cellular network, and sending/receiving packets.

Author

Brandon Wong, Matt Bartos and Ivan Mondragon

Version

TODO

Date

2017-06-01

Function Documentation

uint8 at_write_command	(	char *	uart_string,
		char *	expected_response,
		uint32	uart_timeout
	)

Write AT command to cell module.

Parameters

uart_string	AT command to write to buffer
expected_response	Substring that is expected in the response
uart_timeout	Timeout in milliseconds

Returns

1u if expected response is found; 0u otherwise.

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void construct_generic_request	(	char *	send_str,
		char *	body,
		char *	host,
		char *	route,
		int	port,
		char *	method,
		char *	connection_type,
		char *	extra_headers,
		int	extra_len,
		char *	http_protocol
	)

Constructs a generic HTTP request.

Parameters

send_str	Buffer to store generated HTTP request.
body	HTTP Body.
host	Host.
route	Route.
port	Port.
method	HTTP Method.
connection_type	HTTP Connection.
extra_headers	Any extra HTTP headers.
extra_len	Length of the extra headers.
http_protocol	HTTP protocol.

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uint8 modem_check_network

(

)

Network Registration Report. Function wrapper for AT+CREG command.

Returns

1u on success, 0u otherwise.

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uint8 modem_check_signal_quality	(	int *	rssi,
		int *	fer
	)

Signal Quality Check. Function wrapper for AT+CSQ command.

Parameters

rssi	An int* where rssi is to be stored.
fer	An int* where fer is to be stored.

Returns

1u on success, 0u otherwise.

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uint8 modem_connect

(

)

Establish modem connection with internet.

Returns

Modem state. {OFF, IDLE, READY}

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uint8 modem_disconnect

(

)

Close modem connection to network.

Returns

1u on success, 0u otherwise.

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uint8 modem_get_meid

(

char *

meid

)

Mobile Equipment Identifier. Function wrapper for AT::MEID command.

Parameters

meid	String of size large enough to store an meid of 14 characters. In other words, sizeof(meid) > 14.

Returns

1u on success, 0u otherwise.

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int modem_get_socket_status

(

)

Socket Status. Function wrapper for AT::SS command.

Returns

Socket status on success. 0 or -1 on failure, where 0 means failure to parse the uart received string.

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uint8 modem_pdp_context_toggle

(

uint8

activate_pdp

)

Context Activation. Execution command is used to activate or deactivate the specified PDP context.

Parameters

activate_pdp

enable flag: 0 = deactivate the context 1 = activate the context

Returns

1u on successful toggle, 0u otherwise

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uint8 modem_power_off

(

)

Powers off the modem.

Returns

1u on success.

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uint8 modem_power_on

(

)

Powers on the modem.

Returns

Modem state {OFF, IDLE, READY} or 0u on failure to power on.

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uint8 modem_reset

(

)

Resets the modem.

Returns

Modem state. {OFF, IDLE, READY}

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uint8 modem_send_recv	(	char *	send_str,
		char *	response,
		uint8	get_response,
		int	ssl_enabled
	)

TODO.

Parameters

send_str
response
get_response
ssl_enabled

Returns

1u on success, 0u otherwise.

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uint8 modem_set_error_reports

(

uint8

param

)

Report Mobile Equipment Error. Set command enables/disables the report of result code.

Parameters

param

enable flag: 0 : disable +CME ERROR:<err> reports, use only ERROR report. 1 : enable +CME ERROR:<err> reports, with <err> in numeric format 2 : enable +CME ERROR: <err> reports, with <err> in verbose format

Returns

1u on success, 0u otherwise.

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uint8 modem_set_flow_control

(

uint8

param

)

Set Flow Control. Set command controls the RS232 flow control behaviour.

Parameters

param

One of the following ints: 0 = no flow control 1 = hardware mono-directional flow control (only CTS active) 2 = software mono-directional flow control (XON/XOFF) 3 = hardware bi-directional flow control (both RTS/CTS active) (factory default) 4 = software bi-directional with filtering (XON/XOFF) 5 = pass through: software bi-directional without filtering (XON/XOF

Returns

1u on success, 0u otherwise.

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uint8 modem_setup

(

)

Initialize configurations for the modem.

Returns

1u on success, 0u otherwise.

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uint8 modem_shutdown

(

)

Shutdown sequence to stop/power down modem components.

Returns

1u on success, 0u otherwise.

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uint8 modem_socket_close

(

int

ssl_enabled

)

Closes the socket on the modem.

Parameters

ssl_enabled

Needs to know if ssl is enabled to close the socket properly.

Returns

1u on success, 0u otherwise.

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uint8 modem_socket_dial	(	char *	socket_dial_str,
		char *	endpoint,
		int	port,
		int	construct_new,
		int	ssl_enabled
	)

Opens a remote connection via socket.

Parameters

socket_dial_str
endpoint	Endpoint
port	Port
construct_new	Contruct new socket dial string flag
ssl_enabled	SSL enabled flag

Returns

1u on success, 0u otherwise.

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uint8 modem_startup

(

int *

conn_attempts

)

Startup sequence to power on the modem, start modem components and prepare for sending/receiving messages over the network.

Parameters

conn_attempts

Buffer to store the number of attempted connections

Returns

Modem status.

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int read_response	(	char	message[],
		char *	recv_cmd,
		char *	ring_cmd,
		uint8	get_response,
		int	max_loops,
		int	max_message_size
	)

Reads a HTTP response with a chunked of fixed-length transfer encoding over multiple modem buffers.

Parameters

message	The message buffer to write to
recv_cmd	The Telit receive command to use: AT::SRECV=1,<BYTES> or AT::SSLRECV=1,<BYTES>
ring_cmd	The Telit ring URC to seek: SRING: 1 or SSLRING: 1
get_response	1u if the response is to be downloaded to the response buffer; 0u otherwise
max_loops	The maximum number of times to loop; used as a safeguard
max_message_size	The maximum size of the message

Returns

1u on success, 0u otherwise.

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int send_chunked_request	(	char *	send_str,
		char *	chunk,
		int	chunk_len,
		char *	send_cmd,
		char *	ring_cmd,
		char *	term_char
	)

Breaks request string into packets and sends them.

Parameters

send_str	The request string to be sent
chunk	Empty buffer for holding string chunks
chenk_len	The size of the chunks to send
send_cmd	The AT command used to send data: SSEND, SSENDEXT or SSLSEND
ring_cmd	The ring command to look for: SRING or SSLRING
term_char	The termination character to use: '\032' for Telit

Returns

1u on success, 0u otherwise.

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void uart_string_reset

(

)

Reset modem_received_buffer, clear RX buffer, and reset string index.

Returns

NULL

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