Initial Checkin.

Only DHT (AM3202) supported at this time.

src/dht.c

@@ -0,0 +1,115 @@
+#include "mgos.h"
+
+#ifdef MGOS_HAVE_DHT
+#include "main.h"
+#include "mgos_dht.h"
+#include "mgos_config.h"
+#include "mgos_prometheus_metrics.h"
+#include "mqtt.h"
+
+#define MAX_DHT 8
+
+struct dht_sensor {
+  struct mgos_dht *dht;
+  float temp;
+  float humidity;
+  uint8_t gpio;
+  uint8_t idx;
+};
+
+static struct dht_sensor *s_dht_sensor[MAX_DHT];
+static int s_num_dht = 0;
+
+static void print_chunk(struct mg_connection *nc, char *name, char *fmt, ...) {
+  char chunk[500];
+  int chunklen=0;
+  va_list ap;
+
+  snprintf(chunk, sizeof(chunk), "%s%s", name, fmt[0]=='{' ? "" : " ");
+  va_start(ap, fmt);
+  vsnprintf(chunk+strlen(chunk), sizeof(chunk)-strlen(chunk), fmt, ap);
+  va_end(ap);
+  strncat(chunk, "\n", sizeof(chunk));
+  chunklen=strlen(chunk);
+  LOG(LL_DEBUG, ("Chunk '%s' with length %d", chunk, chunklen));
+  mg_printf(nc, "%X\r\n%s\r\n", chunklen, chunk);
+
+}
+
+static void dht_prometheus_metrics(struct mg_connection *nc, void *user_data) {
+  int i;
+
+  // BUG -- repeated HELP and TYPE makes Prometheus parser bork :(
+  mgos_prometheus_metrics_printf(nc, GAUGE,
+    "temperature", "Temperature in celcius",
+    "{sensor=\"0\",type=\"DHT\"} %f", s_dht_sensor[0]->temp);
+  mgos_prometheus_metrics_printf(nc, GAUGE,
+    "humidity", "Relative humidity percentage",
+    "{sensor=\"0\",type=\"DHT\"} %f", s_dht_sensor[0]->humidity);
+
+  for (i=1; i<s_num_dht; i++) {
+    print_chunk(nc, "temperature", "{sensor=\"%d\",type=\"DHT\"} %f", i, s_dht_sensor[i]->temp);
+    print_chunk(nc, "humidity", "{sensor=\"%d\",type=\"DHT\"} %f", i, s_dht_sensor[i]->humidity);
+  }
+
+  (void) user_data;
+}
+
+static void dht_timer_cb(void *user_data) {
+  struct dht_sensor *dht_sensor = (struct dht_sensor *)user_data;
+  double start;
+  uint32_t usecs=0;
+
+  if (!dht_sensor) return;
+
+  start=mgos_uptime();
+  dht_sensor->temp = mgos_dht_get_temp(dht_sensor->dht);
+  dht_sensor->humidity = mgos_dht_get_humidity(dht_sensor->dht);
+  usecs=1000000*(mgos_uptime()-start);
+  LOG(LL_DEBUG, ("DHT sensor=%u gpio=%u temp=%.2fC humidity=%.0f%% usecs=%u", dht_sensor->idx, dht_sensor->gpio, dht_sensor->temp, dht_sensor->humidity, usecs));
+}
+
+static bool dht_sensor_create(int pin, enum dht_type type) {
+  struct dht_sensor *dht_sensor = calloc(1, sizeof(struct dht_sensor));
+  if (s_num_dht == MAX_DHT) {
+    LOG(LL_ERROR, ("No more sensor slots available (%d added)", MAX_DHT));
+    free(dht_sensor);
+    return false;
+  }
+
+  dht_sensor->dht=mgos_dht_create(pin, type);
+  if (!dht_sensor->dht) {
+    LOG(LL_ERROR, ("Could not create DHT sensor on pin %d", pin));
+    free(dht_sensor);
+    return false;
+  }
+  dht_sensor->gpio=pin;
+  dht_sensor->idx=s_num_dht;
+  s_dht_sensor[dht_sensor->idx] = dht_sensor;
+  s_num_dht++;
+  mgos_set_timer(mgos_sys_config_get_sensors_dht_period()*1000, true, dht_timer_cb, (void*)dht_sensor);
+  return true;
+}
+
+void dht_init() {
+  char *tok;
+
+  memset(s_dht_sensor, 0, sizeof (struct mgos_dht_sensor *) * MAX_DHT);
+  tok = strtok((char *)mgos_sys_config_get_sensors_dht_gpio(), ", ");
+  while (tok) {
+    int gpio;
+    gpio = atoi(tok);
+    tok=strtok(NULL, ", ");
+    dht_sensor_create(gpio, AM2302);
+    mgos_msleep(250);
+  }
+
+  if (s_num_dht>0)
+    mgos_prometheus_metrics_add_handler(dht_prometheus_metrics, NULL);
+}
+
+#else
+void dht_init() {
+  LOG(LL_ERROR, ("DHT disabled, include library in mos.yml to enable"));
+}
+#endif

src/mgos_prometheus_sensors.c

@@ -0,0 +1,9 @@
+#include "mgos_config.h"
+#include "mgos_prometheus_sensors.h"
+
+void dht_init();
+
+bool mgos_prometheus_sensors_init(void) {
+  dht_init();
+  return true;
+}