wireless sensors

[Ralph Mowery]

I bought a wireless inside/outside temperature/humidity display. I got
to thinking about the outside sensor. I am almost sure the sensor does
not transmit all the time because of only 2 AAA batteries.

Any thoughts on how often the sensor updates and sends data back to the
inside unit ? Once a minuit, once ever 10 , or maybe it is when the
temperature changes a half to one degree ?

 

[default]

On Sun, 29 Sep 2019 10:06:37 -0400, Ralph Mowery
<rmowery28146@earthlink.net> wrote:

I bought a wireless inside/outside temperature/humidity display. I got
to thinking about the outside sensor. I am almost sure the sensor does
not transmit all the time because of only 2 AAA batteries.

Any thoughts on how often the sensor updates and sends data back to the
inside unit ? Once a minuit, once ever 10 , or maybe it is when the
temperature changes a half to one degree ?

Temperature doesn't change all that fast so the refresh rate can be
pretty slow and still give good results. But unless they tell you how
often it updates how would you know?

Measure it yourself? Acclimate the outdoor sensor to some temperature
(inside the freezer for instance) then set it outside and watch to see
how often it updates.

 

[Cursitor Doom]

On Sun, 29 Sep 2019 11:43:33 -0400, default wrote:

Temperature doesn't change all that fast so the refresh rate can be
pretty slow and still give good results.

It tends to change most during the morning and evening. So you could
sample sparsely overnight and during the daytime. But this is not
*always* the case by any means. It's trickier than it appears.




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[default]

On Sun, 29 Sep 2019 16:35:58 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Sun, 29 Sep 2019 11:43:33 -0400, default wrote:

Temperature doesn't change all that fast so the refresh rate can be
pretty slow and still give good results.

It tends to change most during the morning and evening. So you could
sample sparsely overnight and during the daytime. But this is not
*always* the case by any means. It's trickier than it appears.

I donno. I have some large digital displays that I've watched for a
few years now and have only seen sudden changes when it rains, or
sunlight hits a sensor. I put one indoors, one outdoors and shielded
from sunlight, and one on the heat pump discharge air. (that one
sunlight can reach in the mornings) All wired sensors with 9 bit
resolution.

I'm sampling every two seconds and a fast change is on the order of 1
degree F in ~20 seconds, but the air temperature isn't changing that
fast, it's caused by rain hitting the sensor or the heat pump is
ramping up.

I've another on a pole outside that flashes the digital temperature by
flashing the 10's digit and then the 1's with the temp. Changes color
too Blue for cool, green for comfortable and red for hot. It is fed
by the low voltage landscape light circuit.

Sample every five minutes then send an RF burst transmission of 100
milliseconds length with the data.... Battery life will depend on
data rate and transmitter power, the sensor uses ~1 ma 3 volts when
active, and down in the nano amp range when standing by between
interrogations.

 

[Tom Gardner]

On 29/09/19 15:06, Ralph Mowery wrote:

I bought a wireless inside/outside temperature/humidity display. I got
to thinking about the outside sensor. I am almost sure the sensor does
not transmit all the time because of only 2 AAA batteries.

Any thoughts on how often the sensor updates and sends data back to the
inside unit ? Once a minuit, once ever 10 , or maybe it is when the
temperature changes a half to one degree ?

I RTFM doesn't help, then you can get a rough idea:
- turn off the base station and turn it on again
- time how long it is between the internal and external
readings appearing
- repeat

The minimum time /might/ indicate the time for the tx/rx to
sync with each other.

Updates don't occur more frequently than the maximum time.

 

[Ralph Mowery]

In article <h3ikF.1329100$xm3.873959@fx15.am4>,
spamjunk@blueyonder.co.uk says...

I RTFM doesn't help, then you can get a rough idea:
- turn off the base station and turn it on again
- time how long it is between the internal and external
readings appearing
- repeat

The minimum time /might/ indicate the time for the tx/rx to
sync with each other.

Updates don't occur more frequently than the maximum time.

The manual does not say how long between updates. It like most consumer
devices just barley tells how to set it up.

There is no simple on/off swithch. You have to remove the batteries and
unplug the wall cube.
Then it takes time for it to resink and I may loose all the setup
information.