ESPMINIMAL – Wi-Fi environmental sensor board

Description

Based on the ESP03 Wi-Fi module, this small and compact board (assembled and tested) detects environmental parameters (of a room, a place in your home, or any other type of building) and publishes the data to the Cloud. It can run for years on two simple AA batteries, without needing a power outlet.

It can be used, for example, to check whether the environment where you store pellets for your stove meets the required temperature and humidity characteristics, or whether the pantry where you keep some food products is truly a “cool, dry place,” or whether your wine cellar has the right temperature and humidity.

In all these cases, it could be handy to view all the necessary parameters on your smartphone, even when you are away from home. To operate, it requires a Wi-Fi signal with Internet access. Data collected in the field is sent wirelessly to an online cloud. The cloud collects and stores the sent data and presents it in an easily analyzable format, such as a graph. If your Wi-Fi signal is strong enough, you can place the circuit just outside your home and use it as a full-fledged weather station.

The board is prepped for inserting two male header strips so it can be used on a breadboard for experiments; the form factor is compatible with Arduino MKR boards.

For programming, an external USB-to-Serial converter is needed, such as code 1686-USBTOUART (not included – see related products). Alternatively, any other USB to UART converter (even four-pin ones) will work, as the DTR and CTS pins are not used.
If you want to program the module using the Arduino IDE, you need to enable the module for programming.

Note: To make assembly easy for everyone, the PCB is double-sided and no SMD components are used, except for the ESP module.

Schematic

ESP03 Technical Specifications

• 802.11 b/g/n
• Ceramic antenna
• Wi-Fi Direct (P2P), soft-AP
• Integrated TCP/IP stack
• Output power +19.5dBm in 802.11b mode
• SDIO 1.1/2.0, SPI, UART
• STBC, 1×1 MIMO, 2×1 MIMO
• A-MPDU & A-MSDU aggregation & 0.4 ms guard interval
• Integrates WEP, TKIP, AES, and WAPI
• Power supply: 3.3 Vdc

Documentation and Useful Links

• https://github.com/esp8266/esp8266-wiki/wiki