Hi folks, hoping for some help with a project I have going. I have esp32c3 for reading temperature and submitting over WiFi to mqtt broker, using deep sleep then waking every 15 minutes to submit temperature.
Sketch below:
#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>
// Wi-Fi credentials
const char* ssid = "Our Hooseynetwork";
const char* password = "Bumhole1pwd";
// MQTT broker details
const char* mqtt_server = "192.168.1.19";
const char* mqtt_user = "fridge1";
const char* mqtt_password = "fridge1";
// Device hostname
const char* hostname = "C3-Fridge-1";
// Pin definitions
#define DS18B20_PIN 6 // GPIO6 for DS18B20
#define BATTERY_PIN 4 // GPIO4 (D4) for ADC battery monitoring
// Voltage divider resistors
#define R1 220000 // 220kΩ
#define R2 220000 // 220kΩ
// Battery voltage limits
#define BATTERY_MAX 4.2
#define BATTERY_MIN 3.0
// Deep sleep time in microseconds (15 minutes)
#define SLEEP_TIME 900000000
// DS18B20 setup
OneWire oneWire(DS18B20_PIN);
DallasTemperature sensors(&oneWire);
// Wi-Fi and MQTT clients
WiFiClient espClient;
PubSubClient client(espClient);
// Function to read battery voltage
float readBatteryVoltage() {
analogSetPinAttenuation(BATTERY_PIN, ADC_11db); // Configure ADC for 0-2.5V range
int raw = analogRead(BATTERY_PIN); // Read raw ADC value
float vOut = (raw / 4095.0) * 2.5; // Convert ADC value to voltage
float vBattery = vOut / 0.5; // Scale to battery voltage
return vBattery;
}
// Function to calculate battery percentage
int calculateBatteryPercentage(float voltage) {
float percentage = ((voltage - BATTERY_MIN) / (BATTERY_MAX - BATTERY_MIN)) * 100.0;
if (percentage > 100) percentage = 100;
if (percentage < 0) percentage = 0;
return (int)percentage;
}
// Function to connect to Wi-Fi
void connectToWiFi() {
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
WiFi.setHostname(hostname);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
}
}
// Function to connect to MQTT broker
void connectToMQTT() {
while (!client.connected()) {
if (client.connect(hostname, mqtt_user, mqtt_password)) {
// Connected
} else {
delay(5000);
}
}
}
void setup() {
sensors.begin(); // Start DS18B20
connectToWiFi();
client.setServer(mqtt_server, 1883);
connectToMQTT();
// Read temperature
sensors.requestTemperatures();
float temperature = sensors.getTempCByIndex(0);
if (temperature == DEVICE_DISCONNECTED_C) {
temperature = -127; // Error value
}
// Read battery voltage
float batteryVoltage = readBatteryVoltage();
// Calculate battery percentage
int batteryPercentage = calculateBatteryPercentage(batteryVoltage);
// Publish data
char payload[100];
snprintf(payload, sizeof(payload), "{\"hostname\":\"%s\",\"temperature\":%.2f,\"battery_percentage\":%d}", hostname, temperature, batteryPercentage);
client.publish("fridge/temperature", payload);
// Deep sleep
esp_sleep_enable_timer_wakeup(SLEEP_TIME);
delay(1000); // Ensure MQTT message is sent
esp_deep_sleep_start();
}
void loop() {
// Not used
}
I have 5 of these, all the same hardware and all the same sketch but I’ve changed the host name on each. All of them run once, 2 of them have worked perfectly every 15 minutes for days now but 3 of them hang up after submitting the message once. I can see on my network that they are just connected the whole time while the working ones are only connected for a few seconds every 15 minutes, if I manually disconnect them through my network controller (unifi) they reconnect and run the sketch but hang up again until I disconnect them again when they’ll do it again.
Is it possible my soldering skills have a part to play in this? I did put them together very quickly. Or are there firmware updates for them and that could be the difference? Or am I barking up the wrong tree entirely? Any help would be greatly appreciated. Thanks for reading.
: never assume your firewall has done what you asked…