Anyone have a BME680?

@Frida that's amazing - thanks! I can't believe I messed that up! :)

I'll update my original post, and will make a note to create a proper module on the Espruino site with it.

If I try with upython on a Wipy, the number is negative.

That sounds wrong to me for a resistance measurement. Pimoroni has a bit of info on https://learn.pimoroni.com/tutorial/sandyj/getting-started-with-bme680-breakout

The sensor produces gas resistance readings in Ohms. These will range from the low thousands up to several hundred thousand Ohms. Every time that you use the sensor, it will take a few minutes (or more if it's the first time you've used it) to stabilise; you'll see the readings creeping upwards. When the readings stabilise, this will be your background reference reading.

So we'd expect the value to be pretty high, but not that high :)