Nevermore StealthMax Sensor PCB by xbst_isik

Nevermore air-quality sensors BME280 & SGP40 mounted on a tiny PCB for Nevermore StealthMax Air Filters, PCB designed by Isik’s Tech.

The sensor helps to monitor temperature, humidity and VOCs. It is designed for Nevermore Max2 and StealthMax air filters but can also be used for other purposes which require air quality monitoring. It can be mounted on top of the StealthMax PCB (header pins included which need to be soldered on if used)

Technical data:

• Sensors: BME280 and SGP40
• Supply voltage: 3.3V
• Interface: I2C
• Size: 10.6×10.6mm

How to install:

Connect the sensor to the RPI:

• 3.3V – RPI Pin 17 or 1
• GND – RPI Pin 6 or 9
• SCL – RPI Pin 5
• SDA – RPI Pin 3

Setup on RPi:

sudo raspi-config

Select 9 Advanced Options –> A7 I2C –> yes (enable I2C) –> yes (load kernel module automatically) –> Finish –> yes (reboot)

Optionally, to improve performance, increase the I2C baud rate from the default of 100KHz to 400KHz by altering /boot/config.txt to include:

dtparam=i2c_arm=on,i2c_baudrate=400000

Install the python BME280 and SGP40 code from the Nevermore Max repo:

sudo apt-get install i2c-tools python-pip
sudo pip install RPi.bme280
sudo wget https://raw.githubusercontent.com/nevermore3d/Nevermore_Max/master/Software/Klipper/sgp40.py -P ~/klipper/klippy/extras
sudo wget https://raw.githubusercontent.com/nevermore3d/Nevermore_Max/master/Software/Klipper/voc_algorithm.py -P ~/klipper/klippy/extras
sudo service klipper restart

If you are using Mainsail and want the SGP40s to be displayed on the dashboard, use these commands:

cd ~/mainsail/
grep -l additionalSensors * -R | xargs sed -i ‘s+additionalSensors=\[+additionalSensors=\[“sgp40”,+g’

More info on GIT