Cumulus Support

Hi,

This post is in-regards to https://cumulus.hosiene.co.uk/viewtopic.php?f=13&t=640

I performed this mod to my station so I can flick a switch so I can have the back light on all the time.. (only when I had in plug in to my pc)

I found when the back light was on it would knock my pressure down .2 to .3 for eg 1003.3 back light off, Back light on it would drop to 1003.0 on its next read.

So I decided to try the half power black light mod... same issue.. so Ive unwired the mod.. over the last few days I have randomly sat there keeping the back light on by pressing the screen over and over... and guess what.. same thing happens.

Now what I want to know does anyone else have the same problem? im guessing the WH 1091/1080/1081 ect use the same board I have the WH-1091.

Try sitting there for a few mins keeping the backlight on, see if your pressure drops

Cheers
Lyle

I wonder whether the small heat generated from the back light/fingers on the screen could have a small influence?

Darknstormy wrote:Hi,

This post is in-regards to https://cumulus.hosiene.co.uk/viewtopic.php?f=13&t=640

I performed this mod to my station so I can flick a switch so I can have the back light on all the time.. (only when I had in plug in to my pc)

I found when the back light was on it would knock my pressure down .2 to .3 for eg 1003.3 back light off, Back light on it would drop to 1003.0 on its next read.

So I decided to try the half power black light mod... same issue.. so Ive unwired the mod.. over the last few days I have randomly sat there keeping the back light on by pressing the screen over and over... and guess what.. same thing happens.

Now what I want to know does anyone else have the same problem? im guessing the WH 1091/1080/1081 ect use the same board I have the WH-1091.

Try sitting there for a few mins keeping the backlight on, see if your pressure drops

Cheers
Lyle

Yup. Can't believe I just did that. Thought it was some kind of joke But just before 3 minutes was up, and I was thinking "that's bull!@#$", the pressure droped from 1005.9 to 1005.8, on an upward trend. After the 48 sec elapse time it went back to 1005.9! WOW. But then I just looked and it's at 1005.7.......and then back to 1005.9...hmmmmm. Baaaaaaaa.

LOL! So glad someone took the time to do it, Thank you I'm not going crazy....my pressure can be steady all day and as soon as I start playing with the backlight for a longer period of time the pressure changes.. some times instant sometimes after two cycles. :S

is the backlight taking power from the pressure sensor? - I think yes... bad voltage regulators on board? I don't know... but even with new batterys and plugged in to usb it still does it
is the backlight heating the sensor - no I dont think so or you would prob get a temp change too?
is the fact your finger is touching the screen it heats up? no same as above

strange I know :S

tested it also and you are right.
my pressure also fluctuated .1 down and later .1 up again.
looks like the power regulation is a bit off.
i think that is why it switches off the light after a few seconds
if it really bothers you,try getting the power for the leds directly from the usb connector(+5v---switch--yellow/red point(bypass the transistor)
if you want half and full power then :

usb+5v---switch(three way)|--leds(full power)
|----resistor---leds(half power)