Weather Station based on HC12 transceiver
Weather Station powered by 18650 Li-ion battery, charged by solar panel. 433MHz HC-12 module is used to send data formatted in JSON. The project is a part of bigger IOT system, and is related to my other projects:
- Various sensors - temperature, humidity, pressure, light intensity, UV index, PM2.5, PM10
- Battery and solar panel voltage measurements
- Possibility to add more sensors (e.g. by I2C)
- Deep sleep to save power
- Debug mode
Main components:
| Device | Description | Price |
|---|---|---|
| Arduino Nano V3 | Main IC (clone) | $2.50 |
| BME280 | Temperature, humidity, pressure sensor | $2.10 |
| MCP9808 | High accuracy temperature sensor | $0.75 |
| BH1750 | Light sensor | $1.00 |
| SI1145 | UV index sensor | $3.70 |
| PMS3003 | Dust sensor | $13.40 |
| HC12 | 433MHz transceiver | $1.95 |
| J5019 | Battery charger with DC-DC converter | $0.69 |
| 2000mAh Li-Ion | 18650 Battery | $2.20 |
| 18650 holder | 18650 Battery holder | $0.35 |
| PC,B | Custom PCB | |
| Housing | Custom housing (3D printed) |
## 4. Libraries
- ArduinoJson
- Adafruit MCP9808
- Adafruit BME280
- Adafruit Sensor
- Adafruit SI1145
- BH1750 by Claws
- PMserial by Alvaro Valdebenito
To run Weather Station, user should change some settings:
Node ID - used to identify device by receiver
#define NODE_ID 103 // Device ID, for internal purpose
Sleep time - how often device will wake up and send measurements
#define SLEEP_TIME 37 // x * 8s = sleep time
Calibration factors - booth should be 1.0 at the beginning, later can be adjusted to fit measured voltages to real values
#define BAT_FACTOR 0.979981 // a = y/x, calibration factor
#define PAN_FACTOR 0.986017 // a = y/x, calibration factor
Altitude - set real value of your location, used for pressure readings
#define ALTITUDE 515.0 //define altitude of location
- Temperature: measured by MCP9808 to ensure high accuracy (0,25ºC)
- Humidity, Pressure: measured by BME280
- Light: measured by BH1750 (lux)
- UV index: measured by SI1145
- PM2.5, PM10: measured by PMS3003
- Voltages: battery and solar panel voltages measured by analog inputs
Measurements send by device using HC-12:
{
"id":103,
"te":4, // temperature
"hu":72, // humidity
"pr":1024.8, // pressure
"p2":34, // PM2.5
"p1":45, // PM10
"ba":4.07, // battery voltage
"pa":4.794 // solar panel voltage
}2021-04-09 V1.0 Stable version
Software:
- Service commands (receive data, e.g. calibration factors, sleep time and store in EEPROM)
Hardware:
- Add additional capacitor to Vcc for better stability
- Change MOSFET circuit - Q1 should be connected to GND, add gate-source resistor
- For future - add anemometer, rainmeter, wind direction etc.
