Open b-g opened 1 year ago
@b-g My understanding of the introduction of the offset was a simple fix for the theory that the USB power supply was heating the ground plane which was a heat sink for various power supply circuits. I have found on my weather board this was the case and that my temperature is also a little off even on the battery supply. I am now running it every minute with wifi upload by connecting a USB supply to the battery connector via a lipo battery and charger. I have made some fixes in PRs for the weather board based on a similar offset for USB to indoor, but yet to apply for the battery power mode.
The temperature offset is done in the boards/indoor.py file in the function starting at line 53, this is done here as temperature also affects humidity from measured humidity. My plan was to put an external BME board in as you have and measure them over time to understand if the offset is linear over ranges of environment temperatures and and then put appropriate logic in that function (for the weather board in my case) for USB and non-USB.
It would be interesting to see your results if the indoor temperature changes significantly over time if you are capturing temperature and temperature2.
@b-g I've added your example to the documentation in PR #184 to make this easier for others in future.
Hi there! Many thanks for the great Enviro Indoor board!
However there seems to be something really fishy with my temperature reading, I've noticed that the onboard temperature reading is constantly far too high. I tried to confirm this, by connecting an additional BME688 breakout with the same chip to cross check e.g.
I'm aware of "compensate for additional heating when on usb power" in https://github.com/pimoroni/enviro/blob/main/enviro/boards/indoor.py#L53 and https://github.com/pimoroni/enviro/blob/main/enviro/config_defaults.py#L4
DEFAULT_USB_POWER_TEMPERATURE_OFFSET = 4.5
. Looking on the my readings, the+4.5
seems rather to make things a lot worse. 🤨?Questions:
+4.5
some legacy code from the past or simply a bug?Bonus: I've couldn't find any documentation in this repo to connect a BreakoutBME68X to the Enviro Indoor ... this did the trick for me: Add the lines below to main.py (around here https://github.com/pimoroni/enviro/blob/main/main.py#L73-L78) and the import
from breakout_bme68x import BreakoutBME68X
on top.Here is the full
main.py
: