uThing::VOC

What is it?

uThing::VOC™ is an open hardware USB dongle useful to quickly integrate or evaluate the Bosch BME680 air quality sensor. The gas sensor within the BME680 detects a range of gases to measure indoor air quality (IAQ) index. Gases that can be detected include Volatile Organic Compounds (VOC) from paints (such as formaldehyde), lacquers, paint strippers, cleaning supplies, furnishings, office equipment, glues, adhesives and alcohol.

The integrated STM32F072 MCU capture raw data from the sensor and use the Bosch's proprietary air quality calculation algorithms to obtain equivalent air-quality, temperature, relative humidity and atmospheric pressure values. These values are then output over a simple Virtual Serial Comm on the USB connector in different configurable formats (JSON, CSV, Human readable or binary).

Why did we make it?

We've seen over and over situations where companies, engineers or tinkerers are working in a relatively complex proof-of-concept IoT project involving several hardware and software components (sensors, actuators, embedded boards, connectivity, backend, analytics and so on) and they need to allocate plenty of resources in the sensors data acquisition part to get the sensor's data into a gateway.If you need to sense air-quality data and decide to use the Bosch BME680, you will find that integrating the Bosch proprietary algorithms is not a trivial task, and that the code size limits its use in constrained platforms like many Arduino boards. This dongle will save you plenty of firmware development time and struggles when your priority is just to get the raw + processed environmental data into a gateway or embedded PC.

What makes it special?

The VCP (Virtual Comm Port) interface makes trivial to export the data to a CSV file without the need to install any software and import in Excel for instance, or use the real-time values in JSON to integrate the sensor into a cloud-connected system, saving several hours to days of integration effort.For example, in Mac/Linux a simple command like cat /dev/cu.usbmodem1A1 > log.csv will start saving the sensor data into a CSV formatted file, making super quick and simple to collect air-quality data even for people with no coding skills.

Features

• Air temperature, humidity, barometric pressure and VOC gas measurements
• Direct indoor air quality (IAQ) index output
• Integrates Bosch proprietary Air-Quality Index algorithm (Bosch Software Environmental Cluster)
• Configurable output formats (JSON, CSV, human readable)
• USB Virtual Comm Port interface

Applications

• Measure Air-Quality from a PC, gateway, RaspberryPi, etc.
• BME680 sensor module evaluation - rapid prototyping
• Quickly measure air-quality in a home, office or warehouse.
• Home automation control (e.g. HVAC).

Specifications

• Power: 5V from USB port, 15 mA.
• Operating range: -40‒+85°C, 10‒90%r.H., 300‒1100 hPa
• Absolute temperature accuracy @25°C: ±0.5°C
• Humidity accuracy tolerance: ±3% r.H.
• IAQ Range: 0-500
• Dimensions: 48x15x5mm

Schematic