We just want to express our gratitude to the HA community for their support. We are delighted to be able to create something new again, and we look forward to seeing how the SCD41 performs. We are using the latest batch of chips, which come with QR codes. After removing them from their original sealed environment, we immediately solder them to the PCB and then combine them with C3, hoping to minimize the impact of long-term exposure to air on the sensors.
Manufacturing CO2 sensors on demand will be our tradition.We thoroughly enjoy the manufacturing process.
This is should not an advertisement; it is simply an expression of gratitude after manufacturing and sharing.
As we have always said, every adventure may end in complete failure. We appreciate everyone’s courage and the opportunity to share our DIY sensor projects.We still know very little about the characteristics of the SCD41 sensor. Generally speaking, they seem to respond quickly, and the readings appear slightly lower.We hope to hear soon from the first adventurers about how the sensors perform.
I think the reason for this phenomenon may be that we calibrated in an indoor environment rather than in a clean outdoor environment.
I think the reason for this phenomenon may be that we calibrated in an indoor environment rather than in a clean outdoor environment.
Additionally, ASC may also be an issue. We disabled ASC (automatic calibration) on the SCD41, which may have caused it to deviate from the baseline data. It may be worth exploring whether ASC is valuable in indoor environments. Note that the SCD30 and SCD40 have ASC enabled. We found an interesting explanation for ASC ( https://breathesafeair.com/carbon-dioxide-monitors ):
Autocalibration: Some carbon dioxide sensors and monitors implement autocalibration, a feature that prevents sensor drift (sensors slowly losing accuracy over time) by regularly calibrating the device.this can cause issues because, at set intervals, the sensor performs ABC (automatic baseline calibration), which sets the lowest carbon dioxide concentration the device has been exposed to as the baseline (typically 400 or 420 ppm). This isn’t an issue if a monitor is regularly exposed to ambient air (around 420–430 ppm). However, if the device is in a room or location where carbon dioxide levels do not reach ambient levels during each calibration cycle (typically seven days), it may incorrectly set a baseline, which can skew all readings until the next automatic calibration.
If your monitor is frequently taken outdoors or is in a room that often experiences ambient or near-ambient CO2 levels, ABC can be very useful. If not, I recommend disabling the feature.
Among the various CO2 sensors used in our experiments, one interesting one is the Sener Sunrise module, which is a very low-power module with an average power consumption of 30 uA. For constructing a portable CO2 monitoring system that can connect to HA, this module has the potential to achieve a battery life of one year with two AA batteries.
Of course, you would need to abandon the ESP32 and opt for low-power Zigbee or BLE solutions, as we have been experimenting with for over a year. This effectively means redesigning the entire system from scratch.
Throughout the process of manufacturing CO2 sensors, what has been most intriguing to us is that CO2 seems insignificant, yet it can be monitored. Some people view it as a benchmark for when indoor air needs to be refreshed, others use it to monitor plant health, and still others employ portable CO2 sensors to assess air quality in public spaces.