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9ddf0858 ML |
1 | #include <libserialport.h> |
2 | #include <stdio.h> | |
3 | #include <stdlib.h> | |
4 | ||
5 | /* Example of how to configure a serial port. | |
6 | * | |
7 | * This example file is released to the public domain. */ | |
8 | ||
9 | /* Helper function for error handling. */ | |
10 | int check(enum sp_return result); | |
11 | ||
12 | /* Helper function to give a name for each parity mode. */ | |
13 | const char *parity_name(enum sp_parity parity); | |
14 | ||
15 | int main(int argc, char **argv) | |
16 | { | |
17 | /* Get the port name from the command line. */ | |
18 | if (argc != 2) { | |
19 | printf("Usage: %s <port name>\n", argv[0]); | |
20 | return -1; | |
21 | } | |
22 | char *port_name = argv[1]; | |
23 | ||
24 | /* A pointer to a struct sp_port, which will refer to | |
25 | * the port found. */ | |
26 | struct sp_port *port; | |
27 | ||
28 | printf("Looking for port %s.\n", port_name); | |
29 | ||
30 | /* Call sp_get_port_by_name() to find the port. The port | |
31 | * pointer will be updated to refer to the port found. */ | |
32 | check(sp_get_port_by_name(port_name, &port)); | |
33 | ||
34 | /* Display some basic information about the port. */ | |
35 | printf("Port name: %s\n", sp_get_port_name(port)); | |
36 | printf("Description: %s\n", sp_get_port_description(port)); | |
37 | ||
38 | /* The port must be open to access its configuration. */ | |
39 | printf("Opening port.\n"); | |
40 | check(sp_open(port, SP_MODE_READ_WRITE)); | |
41 | ||
42 | /* There are two ways to access a port's configuration: | |
43 | * | |
44 | * 1. You can read and write a whole configuration (all settings at | |
45 | * once) using sp_get_config() and sp_set_config(). This is handy | |
46 | * if you want to change between some preset combinations, or save | |
47 | * and restore an existing configuration. It also ensures the | |
48 | * changes are made together, via an efficient set of calls into | |
49 | * the OS - in some cases a single system call can be used. | |
50 | * | |
51 | * Use accessor functions like sp_get_config_baudrate() and | |
52 | * sp_set_config_baudrate() to get and set individual settings | |
53 | * from a configuration. | |
54 | * | |
55 | * Configurations are allocated using sp_new_config() and freed | |
56 | * with sp_free_config(). You need to manage them yourself. | |
57 | * | |
58 | * 2. As a shortcut, you can set individual settings on a port | |
59 | * directly by calling functions like sp_set_baudrate() and | |
60 | * sp_set_parity(). This saves you the work of allocating | |
61 | * a temporary config, setting it up, applying it to a port | |
62 | * and then freeing it. | |
63 | * | |
64 | * In this example we'll do a bit of both: apply some initial settings | |
65 | * to the port, read out that config and display it, then switch to a | |
66 | * different configuration and back using sp_set_config(). */ | |
67 | ||
68 | /* First let's set some initial settings directly on the port. | |
69 | * | |
70 | * You should always configure all settings before using a port. | |
71 | * There are no "default" settings applied by libserialport. | |
72 | * When you open a port it has the defaults from the OS or driver, | |
73 | * or the settings left over by the last program to use it. */ | |
74 | printf("Setting port to 115200 8N1, no flow control.\n"); | |
75 | check(sp_set_baudrate(port, 115200)); | |
76 | check(sp_set_bits(port, 8)); | |
77 | check(sp_set_parity(port, SP_PARITY_NONE)); | |
78 | check(sp_set_stopbits(port, 1)); | |
79 | check(sp_set_flowcontrol(port, SP_FLOWCONTROL_NONE)); | |
80 | ||
81 | /* A pointer to a struct sp_port_config, which we'll use for the config | |
82 | * read back from the port. The pointer will be set by sp_new_config(). */ | |
83 | struct sp_port_config *initial_config; | |
84 | ||
85 | /* Allocate a configuration for us to read the port config into. */ | |
86 | check(sp_new_config(&initial_config)); | |
87 | ||
88 | /* Read the current config from the port into that configuration. */ | |
89 | check(sp_get_config(port, initial_config)); | |
90 | ||
91 | /* Display some of the settings read back from the port. */ | |
92 | int baudrate, bits, stopbits; | |
93 | enum sp_parity parity; | |
94 | check(sp_get_config_baudrate(initial_config, &baudrate)); | |
95 | check(sp_get_config_bits(initial_config, &bits)); | |
96 | check(sp_get_config_stopbits(initial_config, &stopbits)); | |
97 | check(sp_get_config_parity(initial_config, &parity)); | |
98 | printf("Baudrate: %d, data bits: %d, parity: %s, stop bits: %d\n", | |
99 | baudrate, bits, parity_name(parity), stopbits); | |
100 | ||
101 | /* Create a different configuration to have ready for use. */ | |
102 | printf("Creating new config for 9600 7E2, XON/XOFF flow control.\n"); | |
103 | struct sp_port_config *other_config; | |
104 | check(sp_new_config(&other_config)); | |
105 | check(sp_set_config_baudrate(other_config, 9600)); | |
106 | check(sp_set_config_bits(other_config, 7)); | |
107 | check(sp_set_config_parity(other_config, SP_PARITY_EVEN)); | |
108 | check(sp_set_config_stopbits(other_config, 2)); | |
109 | check(sp_set_config_flowcontrol(other_config, SP_FLOWCONTROL_XONXOFF)); | |
110 | ||
111 | /* We can apply the new config to the port in one call. */ | |
112 | printf("Applying new configuration.\n"); | |
113 | check(sp_set_config(port, other_config)); | |
114 | ||
115 | /* And now switch back to our original config. */ | |
116 | printf("Setting port back to previous config.\n"); | |
117 | check(sp_set_config(port, initial_config)); | |
118 | ||
119 | /* Now clean up by closing the port and freeing structures. */ | |
120 | check(sp_close(port)); | |
121 | sp_free_port(port); | |
122 | sp_free_config(initial_config); | |
123 | sp_free_config(other_config); | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | /* Helper function for error handling. */ | |
129 | int check(enum sp_return result) | |
130 | { | |
131 | /* For this example we'll just exit on any error by calling abort(). */ | |
132 | char *error_message; | |
78c3db9b | 133 | |
9ddf0858 | 134 | switch (result) { |
78c3db9b UH |
135 | case SP_ERR_ARG: |
136 | printf("Error: Invalid argument.\n"); | |
137 | abort(); | |
138 | case SP_ERR_FAIL: | |
139 | error_message = sp_last_error_message(); | |
140 | printf("Error: Failed: %s\n", error_message); | |
141 | sp_free_error_message(error_message); | |
142 | abort(); | |
143 | case SP_ERR_SUPP: | |
144 | printf("Error: Not supported.\n"); | |
145 | abort(); | |
146 | case SP_ERR_MEM: | |
147 | printf("Error: Couldn't allocate memory.\n"); | |
148 | abort(); | |
149 | case SP_OK: | |
150 | default: | |
151 | return result; | |
9ddf0858 ML |
152 | } |
153 | } | |
154 | ||
155 | /* Helper function to give a name for each parity mode. */ | |
156 | const char *parity_name(enum sp_parity parity) | |
157 | { | |
158 | switch (parity) { | |
78c3db9b UH |
159 | case SP_PARITY_INVALID: |
160 | return "(Invalid)"; | |
161 | case SP_PARITY_NONE: | |
162 | return "None"; | |
163 | case SP_PARITY_ODD: | |
164 | return "Odd"; | |
165 | case SP_PARITY_EVEN: | |
166 | return "Even"; | |
167 | case SP_PARITY_MARK: | |
168 | return "Mark"; | |
169 | case SP_PARITY_SPACE: | |
170 | return "Space"; | |
171 | default: | |
172 | return NULL; | |
9ddf0858 ML |
173 | } |
174 | } |