Hi,
I am currently working on a student project, where I want to measure the airpreassure along with the airquality.
I have a SDP610 and a BME680.
The SDP610 is fully functional with my code but I have a problem to get the BME680 working correctly.
My circuit is working so it should be a coding problem.
Thank you for your time 
bme680_sdp610_neu.ino (6.88 KB)
Sensirion_Differential_Pressure_Sensors_SDP600Seri-1511233.pdf (464 KB)
tca9548a.pdf (1.16 MB)
In order to make sense of any code we need to see a schematic of your setup. Not a Fritzing physical layout but a real schematic.
Have you or someone else you know asked about this recently. It sounds like this is a class assignment.
Please read this:-
How to use this forum it will tell you haow to ask a question round here.
Grumpy_Mike:
Have you or someone else you know asked about this recently.
That was this thread about connecting multiple 128x64 oled displays. But sensors were also mentioned in that thread, so not impossible this is a class assignment.
Needhelp1234:
I have a SDP610 and a BME680.
One of each sensor? Why do you need a multiplexer? The two sensors have different addresses (0x76 or 0x77 for bme280 and 0x81 (or 0x40 in 7-bit?) for spd610), so I see no need for a multiplexer.