Here are the libraries you would want to have installed to get these devices up and running quickly. The WAKE signal on the CCS811 module must be pulled down to ground in order to establish communications. They all use I2C to communicate, so they will share a common bus for their data and clock signals. The SDA and SCL pins on the ESP32, which are pins 21 and 22 respectively, are connected to the SDA and SCL pins of the CCS811, SHT30-D and SSD1306 modules. The CCS811, SHT30-D and SSD1306 modules are all 3.3V or 5V compatible, so directly connecting the 3.3V output pin on the ESP32 dev board to the VCC input of each module should pose no issue. Wiring Friends don’t let friends use fritzing, unless it’s for wiring diagrams.

The simplicity of MQTT has made it incredibly popular for IOT applications. Clients can then publish data to a topic or multiple topics, and subscribe to several topics at the same time. It’s based on a publish-subscribe model, called so because clients can either publish or subscribe to the server, or “broker” using the protocol’s terminology.ĭata is organized according to topics. Message Queuing Telemetry Transport or MQTT is a popular, lightweight messaging protocol. OLEDs typically have lower power consumption relative to TFT LCD displays. The SSD1306 is a popular driver IC which is typically used to control the wide array of low cost OLED modules that are now available. This small SSD1306 based OLED module can pack quite a bit of information in a relatively tight space. The SHT30-D is one of the faster temperature and humidity sensors out there, outpacing dinosaurs like the hobbyist favorite – the DHT22, in terms of both accuracy and response time, for roughly the same cost. This cute little SHT3X module is also of the generic purple variety.

You’ll also want to let the sensor run for at least 20 minutes on boot before trusting the readings.

The datasheet for this sensor recommends that you apply a “burn in” period, by running it for at least 48 hours before use, which should add some semblance of stability to variations in sensitivity levels. The CCS811 does not directly measure CO2 and as a result, wouldn’t be usable as part of say – a green house gas sensor array. The CCS811 is a hot plate based gas sensor which detects Volatile Organic Compounds (VOCs) levels and provides an equivalent carbon dioxide estimate (eCO2) over I2C.ĮCO2 you say! Why, doesn’t that mean we could use this thing to detect CO2 levels outdoors as well?Īlas, the eCO2 reading is an estimate derived from the proven correlation between CO2 levels and VOC levels indoors. A generic purple CCS811 module – mind the WAKE signal, you’ll need to pull this to ground to communicate with the sensor TVOC/eCO2 Sensor

Esp32 fritzing