I have a couple soil sensors running with simple bolts in the ground. No two sensors will read the same in the same soil, but that is because they are just a relative setup not an accurate setup. Doing what is recommended above is necessary. Determine what % correlates to watering time on the plants. Once this is done it is set and forget.

Also, on your batteries
"The phenomenon itself is very real. If a NiCd battery is repeatedly charged after it has only been partially discharged it will develop a lower voltage and a lower capacity. Fortunately, this effect is reversible by conditioning NiCds."

So I vote to help your poor cheap lamp batteries out by writing logic into your arduino that varies by battery voltage. You can write it in ranges

battery > X volts report every Y minutes
battery > Z volts report every P minutes
battery > .....etc

also to keep your battery in good shape you may consider every so many days ( 2 - 5 ) writing logic that says
every Q days report every 20 seconds (or another interval that will drain battery) until battery voltage = min
then
sleep until battery voltage = max

@mfalkvidd said:

thanks! That makes a ton of sense. These forums are awesome, I really appreciate everybody

@flopp

guys seriously this is just yet another reason to write your reporting interval based on battery voltage and time and not on time alone.

You are using extremely cheap systems with cheap batteries of unknown age that are likely very prone to incur reduced capacity over shorter times and memory from discharge cycles.

See the posts above. This really is one of the greatest ideas I have seen for monitoring, just needs a tweak

With these findings I would set a floor voltage around 1-1.1 V for the arduino to go into sleep mode (find your own floor voltage by looking at your sleep discharge rate and length of night time).

Adding a capacitor to the radio is what I needed to do! Made all the difference in the world!

@flopp

guys seriously this is just yet another reason to write your reporting interval based on battery voltage and time and not on time alone.

You are using extremely cheap systems with cheap batteries of unknown age that are likely very prone to incur reduced capacity over shorter times and memory from discharge cycles.

See the posts above. This really is one of the greatest ideas I have seen for monitoring, just needs a tweak

With these findings I would set a floor voltage around 1-1.1 V for the arduino to go into sleep mode (find your own floor voltage by looking at your sleep discharge rate and length of night time).

I have a couple soil sensors running with simple bolts in the ground. No two sensors will read the same in the same soil, but that is because they are just a relative setup not an accurate setup. Doing what is recommended above is necessary. Determine what % correlates to watering time on the plants. Once this is done it is set and forget.

Also, on your batteries
"The phenomenon itself is very real. If a NiCd battery is repeatedly charged after it has only been partially discharged it will develop a lower voltage and a lower capacity. Fortunately, this effect is reversible by conditioning NiCds."

So I vote to help your poor cheap lamp batteries out by writing logic into your arduino that varies by battery voltage. You can write it in ranges

battery > X volts report every Y minutes
battery > Z volts report every P minutes
battery > .....etc

also to keep your battery in good shape you may consider every so many days ( 2 - 5 ) writing logic that says
every Q days report every 20 seconds (or another interval that will drain battery) until battery voltage = min
then
sleep until battery voltage = max

ha you are on it! caught me editing!

anyways I love your idea, I can guarantee I am looking for these little lights to be on sale every time I go out. This maxes out the clever scale.

@flopp
sure is, It looks like this sketch already has already picked a set single point sleep time that achieved the discharge gradient being less than the charge gradient looking at the angles on the 7 day graph.

My question is why wouldn't you write an algorithm for your sleep setting so you don't have to mess with it if you get a cloudy week etc? You have variable charge gradients depending on weather so why not have a simple variable discharge gradient?

A simple one would be case A - sunny day discharge gradient B- very cloudy day discharge gradient C- emergency charge/top off battery

you could write an equation based off your existing data but honestly you probably wouldn't get much out of it past the simple set listed above that cover 99% of conditions you will see.

side thought

why not write your sleep setting as a variable on the arduino side that is dependent on battery voltage?

if v>(full charge) sleep x hours
if v>(half charge) sleep for y hours
if v<(close to terminal voltage) sleep for z hours/days

this is genious

I have a co-worker who wants to monitor the status of their GFCI outlet that the sump pump is hooked to. Occasionally it will trip when they use their smoker or something and they won't notice until water backs up. What they would like is a simple monitor that would send them an email when there is no power. So I am tossing around some ideas

• current meter and a light bulb - battery pack for node power (expensive)
• LED on all the time and light meter taped together (blocking outside light). If value goes to 0 email is sent (cheap but I wonder how reliable)

They do not currently have a domoticz setup so I would have to get a pi to get this going, adding expense. If anyone has some very simple suggestions I am missing I would really appreciate it!

@Zeph

that has nothing to do with the hardware at all, just a shoddy supply and demand scenario. If they had called me I would have said it is a specialty product for a niche more advanced user than typical and said small quantity too.

link text

I am personally very excited because we know that the quality of these products will be very high and consistent, which is very unlike some of my purchases for components on ebay

actually the more I look at this the more this really needs to be considered, cost wise it is right there with arduinos by the time you add in ancillary stuff. Reliability would be top notch too

this would be all kinds of awesome