mongoose/tutorials/zephyr/mqtt-aws-client/src/main.c
2025-02-27 10:57:08 -03:00

127 lines
4.4 KiB
C

// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved
#include "certs.h"
#include "mongoose.h"
#include <zephyr/net/net_mgmt.h>
struct mg_mgr mgr;
static time_t s_boot_timestamp = 0;
static struct mg_connection *s_sntp_conn = NULL;
static const char *s_url = "mqtts://a3nkain3cvvy7l-ats.iot.us-east-1.amazonaws.com";
static const char *s_rx_topic = "d/rx";
static const char *s_tx_topic = "d/tx";
static int s_qos = 1;
static int s_connected = 0;
static void fn(struct mg_connection *c, int ev, void *ev_data) {
if (ev == MG_EV_OPEN) {
// c->is_hexdumping = 1;
} else if (ev == MG_EV_ERROR) {
// On error, log error message
MG_ERROR(("%p %s", c->fd, (char *) ev_data));
} else if (ev == MG_EV_CONNECT) {
// Set up 2-way TLS that is required by AWS IoT
struct mg_tls_opts opts = {.ca = (char *) s_ca, .cert = (char *) s_cert, .key = (char *) s_key};
mg_tls_init(c, &opts);
} else if (ev == MG_EV_MQTT_OPEN) {
// MQTT connect is successful
struct mg_str topic = mg_str(s_rx_topic);
MG_INFO(("Connected to %s", s_url));
MG_INFO(("Subscribing to %s", s_rx_topic));
struct mg_mqtt_opts sub_opts;
memset(&sub_opts, 0, sizeof(sub_opts));
sub_opts.topic = topic;
sub_opts.qos = s_qos;
mg_mqtt_sub(c, &sub_opts);
c->data[0] = 'X'; // Set a label that we're logged in
} else if (ev == MG_EV_MQTT_MSG) {
// When we receive MQTT message, print it
struct mg_mqtt_message *mm = (struct mg_mqtt_message *) ev_data;
MG_INFO(("Received on %.*s : %.*s", mm->topic.len, mm->topic.buf,
mm->data.len, mm->data.buf));
} else if (ev == MG_EV_POLL && c->data[0] == 'X') {
static unsigned long prev_second;
unsigned long now_second = (*(unsigned long *) ev_data) / 1000;
if (now_second != prev_second) {
struct mg_str topic = mg_str(s_tx_topic), data = mg_str("{\"a\":123}");
MG_INFO(("Publishing to %s", s_tx_topic));
struct mg_mqtt_opts pub_opts;
memset(&pub_opts, 0, sizeof(pub_opts));
pub_opts.topic = topic;
pub_opts.message = data;
pub_opts.qos = s_qos, pub_opts.retain = false;
mg_mqtt_pub(c, &pub_opts);
prev_second = now_second;
}
}
}
// example system time()-like function
time_t ourtime(time_t *tp) {
time_t t = s_boot_timestamp + mg_millis() / 1000;
if (tp != NULL) *tp = t;
return t;
}
// SNTP callback. Modifies s_boot_timestamp, to make ourtime() correct
static void sfn(struct mg_connection *c, int ev, void *ev_data) {
if (ev == MG_EV_SNTP_TIME) {
int64_t t = *(int64_t *) ev_data;
MG_INFO(("Got SNTP time: %lld ms from epoch", t));
s_boot_timestamp = (time_t) ((t - mg_millis()) / 1000);
// We need correct time in order to get HTTPs working, therefore,
// making https request from SMTP callback
if (!s_connected) {
MG_INFO(("Connecting to : [%s]", s_url));
struct mg_mqtt_opts opts = {.clean = true};
mg_mqtt_connect(&mgr, s_url, &opts, fn,
NULL); // Create client connection
s_connected = 1;
}
} else if (ev == MG_EV_CLOSE) {
s_sntp_conn = NULL;
}
}
// Periodic timer syncs time via SNTP
static void timer_fn(void *arg) {
struct mg_mgr *mgr = (struct mg_mgr *) arg;
if (s_sntp_conn == NULL) s_sntp_conn = mg_sntp_connect(mgr, NULL, sfn, NULL);
if (s_boot_timestamp < 9999) mg_sntp_request(s_sntp_conn);
}
// Zephyr: Define a semaphore and network management callback to be able to wait
// until our IP address is ready. The main function will start and block on this
// semaphore until this event handler releases it when the network is ready
K_SEM_DEFINE(run, 0, 1);
static void zeh(struct net_mgmt_event_callback *cb, uint32_t mgmt_event,
struct net_if *iface) {
if (mgmt_event == NET_EVENT_L4_CONNECTED) k_sem_give(&run);
}
int main(int argc, char *argv[]) {
// Zephyr: Register the network management callback and block on the semaphore
struct net_mgmt_event_callback ncb;
net_mgmt_init_event_callback(&ncb, zeh, NET_EVENT_L4_CONNECTED);
net_mgmt_add_event_callback(&ncb);
k_sem_take(&run, K_FOREVER);
mg_log_set(MG_LL_DEBUG);
mg_mgr_init(&mgr);
mg_timer_add(&mgr, 5000, MG_TIMER_REPEAT | MG_TIMER_RUN_NOW, timer_fn, &mgr);
// Start infinite event loop
MG_INFO(("Mongoose version : v%s", MG_VERSION));
mg_http_connect(&mgr, s_url, fn, NULL); // Create client connection
for (;;) mg_mgr_poll(&mgr, 1000);
mg_mgr_free(&mgr);
return 0;
}