Integrate the Co2 readings from a Techno Line WL 1030 into ESPhome / Home Assistant
The Co2 sensor used by the Technoline WL 1030 seems to be a Cubic NDIR CO2 Sensor Module CM1106-C. This sensor has a PWM output, that can be used by an ESP to measure the Co2 readings.
This solution does not read any other values than the Co2!
- Open the Techno Line (There is a hidden screw under the stand)
- Connect VIN from the Co2 to ESP VIN/BAT/5V
- Connect GND from the Co2 to ESP GND
- Connect PWM from the Co2 to ESP input pin (I used GPIO14)
- Solder a Pull-Up of 5k-10k between VIN and PWM (I'm not 100% sure that this is needed, but the datasheet mentions that you need it while using an oscilloscope)
...
sensor:
- platform: pulse_width
pin: GPIO14
name: Co2
update_interval: 30s
filters:
- lambda: return (x-0.002) * 5000;
unit_of_measurement: "ppm"
icon: "mdi:molecule-co2"
device_class: "carbon_dioxide"
state_class: "measurement"
accuracy_decimals: 0
Example output, taken from ESP home in Home Assistant
[13:57:06][D][sensor:093]: 'Co2': Sending state 793.76996 ppm with 0 decimals of accuracy
[13:57:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.172 s
[13:57:36][D][sensor:093]: 'Co2': Sending state 849.76495 ppm with 0 decimals of accuracy
[13:58:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.179 s
[13:58:06][D][sensor:093]: 'Co2': Sending state 882.71002 ppm with 0 decimals of accuracy
[13:58:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.165 s
[13:58:36][D][sensor:093]: 'Co2': Sending state 812.76001 ppm with 0 decimals of accuracy
[13:59:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.155 s
[13:59:06][D][sensor:093]: 'Co2': Sending state 762.74500 ppm with 0 decimals of accuracy
[13:59:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.155 s
[13:59:36][D][sensor:093]: 'Co2': Sending state 763.74506 ppm with 0 decimals of accuracy
[14:00:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.168 s
[14:00:06][D][sensor:093]: 'Co2': Sending state 828.73004 ppm with 0 decimals of accuracy
[14:00:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.168 s
[14:00:36][D][sensor:093]: 'Co2': Sending state 831.88501 ppm with 0 decimals of accuracy
[14:01:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.155 s
[14:01:06][D][sensor:093]: 'Co2': Sending state 764.94000 ppm with 0 decimals of accuracy
[14:01:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.145 s
[14:01:36][D][sensor:093]: 'Co2': Sending state 716.89502 ppm with 0 decimals of accuracy
[14:02:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.141 s
[14:02:06][D][sensor:093]: 'Co2': Sending state 692.81995 ppm with 0 decimals of accuracy
[14:02:36][C][pulse_width:026]: 'Co2' - Got pulse width 0.143 s
[14:02:36][D][sensor:093]: 'Co2': Sending state 705.92505 ppm with 0 decimals of accuracy
[14:03:06][C][pulse_width:026]: 'Co2' - Got pulse width 0.141 s
[14:03:06][D][sensor:093]: 'Co2': Sending state 695.86005 ppm with 0 decimals of accuracy
