Bryan Parke <[email protected]> writes: > Hi all. Weewx is great! I'm very impressed with all that it can do. Here > is a bit about my setup. > > 1) AcuRite 5-in-1 pro broadcasting on 433mhz > 2) Raspberry Pi with rtl-sdr capturing data using rtl_433 > 3) Using the sdr driver > 4) Using mosquitto to publish real-time weather data and viewing that in > belchertown realtime > 5) Pushing every 10 minutes to the CWOP for APRS ( > https://aprs.fi/info/a/KM6YFK-13) > > All is working as expected, no issues at all. > > My question is this: I'd like to get barometric pressure also, but the > 5-in-1 doesn't have that. My understanding is that in order to get > barometric pressure, I would need to purchase the AcuRite receiver/screen > and plug it in via USB to my raspberry pi; in that the barometric pressure > sensor is actually in the screen/display unit. > > 1) is that true? Or is there actually another way to get the pressure > using the 5-in-1? > 2) Is there another device that you all like that would accomplish the same > thing?
My impression is that for the 5n1, like many other stations including Davis, has the pressure sensor in the console/receiver, rather than in the (outside) sensor suite. Another approach is to get a BME280 or similar and read pressure from it. I have an adafruit breakout board with one, and read temp, humidity (in a room inside) and pressure, and send that over MQTT using an ESP8266 and a few lines of code in lua (NodeMCU). You could hook this up to your RPI directly - it's just i2c. Beware that the BME280 and other such things read "station pressure", which is the absolute air pressure at your location (modulo calibration errors). Weather reports are generally "barometric pressure", which is station pressure reduced to sea level based on the observed characteristics, and I believe CWOP uses "altimeter pressure", which is station pressure reduced assuming a standard atmosphere. (Barometric pressure seems to require data from 12h ago and it's a FAQ why it's not reported when a station is first installed.) I would think at the 99% level, but I am not 100% sure, that weewx will calculate barometric and altimeter pressure if you provide it with station pressure and configured altitude. You will need to get accurate altitude, and then you will probably need a calibration tweak on top of that. If you feel like having the acurite screen -- and then you can use USB instead of needing rtlsdr -- that seems like a completely reasonable approach. A friend has one and it seems to report pressure just fine except that it is bizarrely configured for inHg instead of hPa :-) -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/rmitv08ltqx.fsf%40s1.lexort.com.
