SparkFun Listens to the Light with a New Photoacoustic Carbon Dioxide Sensor
Infineon-powered high-accuracy CO2 sensor is also joined by a pair of human presence and motion detectors, all supporting Qwiic connections.
SparkFun has announced the launch of a new high-accuracy carbon dioxide sensor, based on the Infineon XENSIV PASCO2V01 — alongside a pair of new human presence and motion sensors based on STMicroelectronics' STHS34PF80 black-body radiation sensor.
"The new SparkFun Qwiic Photoacoustic Spectroscopy CO2 Sensor […] utilizes Infineon's PASCO2V01 sensor to provide you with highly accurate CO2 data," SparkFun's Chris McCarty explains of the company's latest environmental sensor board, "with a combination of narrow-band filtered IR [infrared] light and audio to measure CO2 molecule concentration."
As the name implies, the Infineon XENSIV PASCO2V01 photoacoustic spectroscopy sensor works in a somewhat unusual way: the sensor emits infrared light, but rather than measuring the effect of the gas through which it passes optically it uses sound instead — tracking the tiny noises made as the infrared light interacts with carbon dioxide in the air.
SparkFun's implementation of the sensor places Infineon's module on a larger breakout borad which brings out I2C, UART, and pulse-width modulation (PWM) signals on unpopulated 0.1" pin headers. Naturally, there's also the option of using a solderless Qwiic connector — with two included on the board, making it easier to integrate into an existing Qwiic-based project.
The sensor itself can measure concentrations of carbon dioxide up to 32,000 parts per million (PPM), with its peak accuracy — found in the range of 400 to 5,000 PPM — rated at ±30 PPM plus three per cent of the reading. That figure, however, comes with a caveat: the device needs a week-long calibration period, including at least half an hour or active measurements outdoors.
At the same time, SparkFun has launched two new human presence and motion sensors, both based on the STMicro STHS34PF80 black-body radiation sensor. "The sensor is composed of a matrix of floating vacuum thermal transistors (MOS) split into two parts, one exposed to IR radiation and the other one shielded," McCarty explains.
"The differential reading between the segments, allows the sensor to remove self-heating effects. The STHS34PF80 also incorporates algorithms to detect and discriminate between stationary and moving objects."
The SparkFun Photoacoustic Spectroscopy CO2 Sensor is now available on the SparkFun store at $59.95 before volume discounts; the SparkFun Human Presence and Motion Sensor is priced at $14.95 for the full-size version or $15.50 for a more compact "Mini" variant.
