1 #include <libserialport.h>
5 /* Example of how to wait for events on multiple ports.
7 * This example file is released to the public domain. */
9 /* Helper function for error handling. */
10 int check(enum sp_return result);
12 int main(int argc, char **argv)
14 /* Get the port names from the command line. */
16 printf("Usage: %s <port name>...\n", argv[0]);
19 int num_ports = argc - 1;
20 char **port_names = argv + 1;
22 /* The ports we will use. */
23 struct sp_port *ports[num_ports];
25 /* The set of events we will wait for. */
26 struct sp_event_set *event_set;
28 /* Allocate the event set. */
29 check(sp_new_event_set(&event_set));
31 /* Open and configure each port, and then add its RX event
32 * to the event set. */
33 for (int i = 0; i < num_ports; i++) {
35 printf("Looking for port %s.\n", port_names[i]);
36 check(sp_get_port_by_name(port_names[i], &ports[i]));
38 printf("Opening port.\n");
39 check(sp_open(ports[i], SP_MODE_READ));
41 printf("Setting port to 9600 8N1, no flow control.\n");
42 check(sp_set_baudrate(ports[i], 9600));
43 check(sp_set_bits(ports[i], 8));
44 check(sp_set_parity(ports[i], SP_PARITY_NONE));
45 check(sp_set_stopbits(ports[i], 1));
46 check(sp_set_flowcontrol(ports[i], SP_FLOWCONTROL_NONE));
48 printf("Adding port RX event to event set.\n");
49 check(sp_add_port_events(event_set, ports[i], SP_EVENT_RX_READY));
52 /* Now we can call sp_wait() to await any event in the set.
53 * It will return when an event occurs, or the timeout elapses. */
54 printf("Waiting up to 5 seconds for RX on any port...\n");
55 check(sp_wait(event_set, 5000));
57 /* Iterate over ports to see which have data waiting. */
58 for (int i = 0; i < num_ports; i++) {
59 /* Get number of bytes waiting. */
60 int bytes_waiting = check(sp_input_waiting(ports[i]));
61 printf("Port %s: %d bytes received.\n",
62 sp_get_port_name(ports[i]), bytes_waiting);
65 /* Close ports and free resources. */
66 sp_free_event_set(event_set);
67 for (int i = 0; i < num_ports; i++) {
68 check(sp_close(ports[i]));
69 sp_free_port(ports[i]);
75 /* Helper function for error handling. */
76 int check(enum sp_return result)
78 /* For this example we'll just exit on any error by calling abort(). */
82 printf("Error: Invalid argument.\n");
85 error_message = sp_last_error_message();
86 printf("Error: Failed: %s\n", error_message);
87 sp_free_error_message(error_message);
90 printf("Error: Not supported.\n");
93 printf("Error: Couldn't allocate memory.\n");