$1.99 – $9.99
This is my wireless climate sensor. The sensor can support DHT22 or DS18B20+. The source code can be found here. It consumes around 10 μA while in standby. It sends an update over ESPNow to the hub every 15 minutes. It can also be used in a stand-alone mode, without the hub, to connect directly to Wi-Fi. The sensor was designed using an ESP8266 Wi-Fi module, an ATtiny microcontroller, LDO and DHT22/DS18B20+ ( recommended). It has a built-in Lithium-Ion/Lithum-Polymer charger and a micro-USB plug for charging. Please note: the ATtiny13a needs to be pre-flashed before it is soldered in.
Schematic
Assembly
Components (BOM)
| Temperature Sensor | DHT22 or DS18B20+ | |
| ATtiny | ATTINY13A-SSU (pre-flash before solder) | MICROCHIP |
| USB micro plug | ||
| 3.3v LDO | SPX3819M5-L-3-3/TR | EXAR |
| ESP-12F | ESP-12F(ESP8266MOD) | Ai-Thinker |
| Diode | 1N4007 | |
| Resistors | 2 x 5.1k 1%, 2 x 10k, 1M 1%, 3.3M 1%, 1k | 0603 or 0805 (tight fit) |
| Capacitors | 2 x 4.7u, 10u, 100n, 10n | 0603 or 0805 (tight fit) |
| LEDs | red | 0603 or 0805 (tight fit) |
| Weight | 5 g |
|---|---|
| Dimensions | 4.75 × 2.35 × 0.1 cm |
