Wind direction reading 0 most of the time.

frenchie
New Member

Posts: 16

Wind direction reading 0 most of the time. Dec 19, 2020 6:13:21 GMT -8

Quote

Post by frenchie on Dec 19, 2020 6:13:21 GMT -8

Hi DOC

Not sure if I have a problem with the wind vane - giving wind direction ! Checked and rechecked cabling - all is good.

Problem is all I seem to get out of the weather vane is 0 or 337 degrees ! Below is a print out of the weatherrack test script. As you will see lots of different voltages, but mostly 0 for wind direction. Am I missing something ?

Thank you for any help / guidance

-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 1.19 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 2.13 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 4871.25)
(' voltageValue = ', 4.87125)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 4.898 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 2.68 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 6.03 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 2109.375)
(' voltageValue = ', 2.109375)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 2.117 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 3.87 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 9.25 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 1495.125)
(' voltageValue = ', 1.495125)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 1.499 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 6.24 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 10.96 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 956.0625)
(' voltageValue = ', 0.9560625)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 0.958 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 6.24 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 10.80 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 1497.75)
(' voltageValue = ', 1.49775)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 1.508 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 5.65 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 10.82 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 1495.875)
(' voltageValue = ', 1.495875)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 1.499 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 5.06 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 9.61 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 1491.9375)
(' voltageValue = ', 1.4919375)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 1.499 V
-----------------
-----------------
----------------------------------------
-----------------
SDL_Pi_WeatherRack Library
WeatherRack Weather Sensors
-----------------
Rain Total= 0.00 in
Wind Speed= 7.13 MPH
max Ever Wind Speed= 8.92 MPH
MPH wind_gust= 13.79 MPH
max Ever Gust wind_gust= 18.06 MPH
(' value = ', 1495.125)
(' voltageValue = ', 1.495125)
Wind Direction= 0.00 Degrees
Wind Direction Voltage= 1.499 V

svejk
New Member

Posts: 14

Wind direction reading 0 most of the time. Dec 21, 2020 13:54:45 GMT -8 SDL likes this

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Post by svejk on Dec 21, 2020 13:54:45 GMT -8

I have the same problem and I tracked it down to under-voltage on the power supply to the SkyWeather box. I have a long USB run from the transformer to the box. The test setup worked fine, but once installed with a long power supply run it started to behave as you described. I tested my theory this morning by taking a long extension cord outside, plugged the power supply into it, and and plugged the power supply directly Into the pi. All directional readings were suddenly correct! When I put it back on the long USB run, the problem resumed. :-(

If voltages from the WeatherRack are not within 5% of the expected value for the current wind direction then one of two things happens: 1.) It will report an incorrect direction corresponding to a voltage that it finds within the + or - 5% range, or 2.) if there is not a valid voltage within the + or - 5% range to match your measured value then it will report back a default of 0 degrees (North).

I haven't figured out an alternate setup for power to my SkyWeather yet, but at least I now know why wind direction is incorrect.

frenchie
New Member

Posts: 16

Wind direction reading 0 most of the time. Dec 23, 2020 9:27:36 GMT -8

Quote

Post by frenchie on Dec 23, 2020 9:27:36 GMT -8

HI Svejk, thanks for this input. I wondered if this might be the case. Oddly, I do not have a very long power supply cable and I am using a suitable PSU.
I guess I could try another power unit to see if that is the issue.

svejk
New Member

Posts: 14

Wind direction reading 0 most of the time. Dec 23, 2020 10:16:24 GMT -8

Quote

Post by svejk on Dec 23, 2020 10:16:24 GMT -8

I measured the voltage at the GPIO pin headers. Pins 2 and 4 (5v) measured at 4.75v while pins 1 and 17 (3.3v) measured correctly at 3.3 volts. I'm using a 2.5 amp power supply, however, I'm wondering if the voltage measurements are under load or if they drop when when a wind vane reading is taken. Not sure how to determine that.

Last Edit: Dec 23, 2020 10:21:38 GMT -8 by svejk

smurphy
Full Member

Posts: 169
Raspberry Pi: Yes
Other Device: many ...

Wind direction reading 0 most of the time. Dec 24, 2020 7:03:29 GMT -8

Quote

Post by smurphy on Dec 24, 2020 7:03:29 GMT -8

What I did, is to use a 12V AC/DC power converter in my house. The cable is about 20m long. Just below the Weatherbox I have a 12V/5V DC/DC converter. Avout 2m from the weatherbox because of the lightning detector. Works great

SDL
Global Moderator

Posts: 5,655
Raspberry Pi: Yes
Other Device: PC, arduino, beagleBone

Wind direction reading 0 most of the time. Dec 24, 2020 15:23:16 GMT -8

Quote

Post by SDL on Dec 24, 2020 15:23:16 GMT -8

4.75V is pretty low. These devices are only specified down to 4.75 and that low of a voltage will screw up the wind direction measurement.

Take a look at this set of postings too:

forum.switchdoc.com/thread/1437/weird-measurements

BP

frenchie
New Member

Posts: 16

Wind direction reading 0 most of the time. Dec 27, 2020 9:45:45 GMT -8 SDL likes this

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Post by frenchie on Dec 27, 2020 9:45:45 GMT -8

Thank you for the pointer Svejk.

I tried a few ways to power the RaspberryPI. Which by the way is a Raspberry PI 4B v1.1.

I tried several power charges all of which are rated sufficiently, I tried my iPAD Prod charger, and also a variety of cables I had lying around all with no joy on the windir values.. I almost gave up, and came across a Laptop charger which is only USB-C and not apple. This seems to work a treat.

Seems I might need to review using a RP4B or another means of getting power to the box.

smurphy, I might have to do something like that !

Last Edit: Dec 27, 2020 9:46:59 GMT -8 by frenchie

Post by frenchie on Dec 19, 2020 6:13:21 GMT -8

Post by svejk on Dec 21, 2020 13:54:45 GMT -8

Post by frenchie on Dec 23, 2020 9:27:36 GMT -8

Post by svejk on Dec 23, 2020 10:16:24 GMT -8

Post by smurphy on Dec 24, 2020 7:03:29 GMT -8

Post by SDL on Dec 24, 2020 15:23:16 GMT -8

Post by frenchie on Dec 27, 2020 9:45:45 GMT -8

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