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 = malloc(num_ports * sizeof(struct sp_port *));
27 /* The set of events we will wait for. */
28 struct sp_event_set *event_set;
30 /* Allocate the event set. */
31 check(sp_new_event_set(&event_set));
33 /* Open and configure each port, and then add its RX event
34 * to the event set. */
35 for (int i = 0; i < num_ports; i++) {
37 printf("Looking for port %s.\n", port_names[i]);
38 check(sp_get_port_by_name(port_names[i], &ports[i]));
40 printf("Opening port.\n");
41 check(sp_open(ports[i], SP_MODE_READ));
43 printf("Setting port to 9600 8N1, no flow control.\n");
44 check(sp_set_baudrate(ports[i], 9600));
45 check(sp_set_bits(ports[i], 8));
46 check(sp_set_parity(ports[i], SP_PARITY_NONE));
47 check(sp_set_stopbits(ports[i], 1));
48 check(sp_set_flowcontrol(ports[i], SP_FLOWCONTROL_NONE));
50 printf("Adding port RX event to event set.\n");
51 check(sp_add_port_events(event_set, ports[i], SP_EVENT_RX_READY));
54 /* Now we can call sp_wait() to await any event in the set.
55 * It will return when an event occurs, or the timeout elapses. */
56 printf("Waiting up to 5 seconds for RX on any port...\n");
57 check(sp_wait(event_set, 5000));
59 /* Iterate over ports to see which have data waiting. */
60 for (int i = 0; i < num_ports; i++) {
61 /* Get number of bytes waiting. */
62 int bytes_waiting = check(sp_input_waiting(ports[i]));
63 printf("Port %s: %d bytes received.\n",
64 sp_get_port_name(ports[i]), bytes_waiting);
67 /* Close ports and free resources. */
68 sp_free_event_set(event_set);
69 for (int i = 0; i < num_ports; i++) {
70 check(sp_close(ports[i]));
71 sp_free_port(ports[i]);
77 /* Helper function for error handling. */
78 int check(enum sp_return result)
80 /* For this example we'll just exit on any error by calling abort(). */
84 printf("Error: Invalid argument.\n");
87 error_message = sp_last_error_message();
88 printf("Error: Failed: %s\n", error_message);
89 sp_free_error_message(error_message);
92 printf("Error: Not supported.\n");
95 printf("Error: Couldn't allocate memory.\n");