I have a question about how to use the C1001.

[choejoongho]

Hi,

I'm using DFRobot's C1001 sensor in Sleep mode to measure respiration rate and detect human presence. I've encountered various issues during testing with the C1001, and have a few questions.

1. The C1001 sensor is connected to the ESP32-C6 board via TX/RX. I positioned it about 80cm away from my chest, facing my chest at head height. Within seconds of sitting down on a chair, the C1001's LED turns red and the Human Presence value changes to 1. However, the respiration rate is not detected until about two minutes later. Is there a way to detect respiration rate more quickly? The primary purpose of the C1001 is not to capture data during sleep, but to measure respiration rate in real-life situations (such as sitting in a chair, reading a book, or typing). Therefore, I need a faster respiration rate measurement.

2. Sometimes, even after I get up from my chair and leave the office, the Human Presence value remains at 1 and the respiration rate is still being measured. After a certain amount of time (5, 10 minutes, it varies), the presence and respiration rate reset to 0, but sometimes the respiration rate is measured even when no one is present for a long time. I'd like to know if this is a characteristic of the sleep mode algorithm. Or, if there's a PC nearby, can the vibration of the PC be reflected in the respiration rate? If possible, is there a way to have the respiration rate be immediately reflected when no one is present?

3. When I sit in the chair in front of the C1001, the human presence changes to 1, but the respiration rate doesn't measure for a long time and remains at 0. Sometimes, the respiration rate only appears after 5 minutes, and often, it remains at 0 even after sitting for tens of minutes. Are there any conditions for normal respiration rate measurement? Do I need to turn the power off and on every time, reset it, or hold it close to my chest?

4. When I'm testing while sitting alone in the office or briefly moving away, the results often appear normal when I'm alone. However, even when I leave my chair and go into the hallway, the respiration rate continues to be measured, even when there are 3 ~ 5 people nearby (3 ~ 5 meters away). I believe the Human Presence value remains at 1 because it detects people 3 ~ 5 meters away, but this behavior differs from the explanation that it measures the respiration rate of people within 1.5 meters. I'd like to know what the issue is.

I'm investigating whether there's a problem with the UART TX/RX data format. However, when no one is present, the respiration rate changes slightly in the debug log(14, 15, 16...), indicating that the data parsing is working properly. If this is a characteristic of the C1001's algorithm for measuring sleep states in sleep mode, I'd like to know if there's a way to initiate measurements more quickly and adapt to the presence and absence of people in life environments.

I apologize for my poor English, as I'm not a native English speaker. Thank you for your understanding.

[choejoongho]

Hi,
Has anyone experienced this phenomenon? I've emailed DFRobot, but haven't received a response yet. Does anyone know of a website or forum where I can get information about DFRobot's C1001 sensor?

[choejoongho]

Hi,
I purchased several C1001s and am testing them. When a wall is behind the C1001 module, respiration rate is measured within a minute. However, when there is nothing behind, respiration rate is measured after 10 to 20 minutes, or it is not measured at all. Is it necessary to have a wall or something similar behind the module during installation? Has anyone experienced any differences in measurement results depending on this installation method?