Add clamp calibration values

[GoogleCodeExporter]

What steps will reproduce the problem?
1.The ability to define a floor, ceil, offset and gradient so as to refine 
accuracy of the returned power from a clamp/sensor.
2.
3.

What is the expected output? What do you see instead?
All power values below floor are set to 0. Default value of floor = 0.
All power values above ceil are set to ceil. Default value of ceil = -1 (ignore)
All power values between ceil and floor can be multipled by a gradient. Default 
1.
All power values between floor and ceil can have an offset added (default 0)

This would allow for some simple re-calibration of the power.
y=mx+b

Example values 
floor = 50 (per clamp) or 150 (per transmitter)
ceil = 5000 (per clamp) or 15000 (per transmitter)
offset = 200 (per clamp) or 600 (per transmitter)
gradient = 1.1 (per clamp and/or transmitter)

floor is applied before y=mx+b
ceil is applied after y=mx+b

What version of the product are you using? On what operating system?
V115

Please provide any additional information below.

The clamps when installed in a fuse box pick up some stray magnetic fields that 
give rise to extra false currents. To have the ability to scale and manipulate 
the returned power values would be advantageous.

My 3 phase SMA inverter gives very accurate power output readings, but stray 
magnetic fields can cause the clamps to still return a power readings on the 
EnviR when the inverter has switched off. I was getting 150W/clamp at one 
stage, but with a little bit more care I managed to reduce that down to 
50W/clamp by separating the clamps and orienting them at right angles to each 
other. From observation it seems that the clamps very quickly get accurate 
again once above the floor level. My only real requirement is for floor! but I 
add ceil, offset and gradient for completeness. The response is probably not 
linear anyway, but who knows what linearisation is done in the transmitter. 
y=mx+b would be a good start.

Original issue reported on code.google.com by sireland...@gmail.com on 19 Aug 2013 at 4:51

[GoogleCodeExporter]

Ok. As I understood you want to have the ability to change the usage data that 
measureit receive from the Envi.

How should this logical work?

Does measureit increase or reduce every data it receives automatically from an 
defined factor per sensor / clamp?

And what happens at you home that you are having "stray magnetic fields"  :)

Original comment by lalelu...@gmail.com on 19 Aug 2013 at 9:26

• Removed labels: Type-Defect

[GoogleCodeExporter]

if value received by enviR <= floor then return 0.
if value received by enviR >= ceil and ceil != -1 then return ceil

new value = value received by enviR*gradient + offset;

if new value <= floor then return 0.
if new value >= ceil and ceil != -1 then return ceil

return new value

Should be applied per clamp then per sensor.

Examples

floor = 100W Ceil = 5000W Offset = -50 Gradient = 1.1 

Value sent by enviR = 50W then return 0 as below floor.
Value sent by enviR = 6000W then return 5000 as above ceil
Value sent by enviR = 120 multiplied by 1.1 and subtract 50 return 0 as below 
floor
Value sent by enviR = 150 multiplied by 1.1 and subtract 50 return 115
Value sent by enviR = 4900 multiplied by 1.1 and subtract 50 return 5000 as 
above Ceil
Value sent by enviR = 2500 multiplied by 1.1 and subtract 50 return 2700

floor = 0W Ceil = -1 Offset = 0 Gradient = 1.0
These are the default values and will not cause the data to change at all.

Stray magnetic fields affect my thirst and make me drink more beers!

Original comment by sireland...@gmail.com on 21 Aug 2013 at 12:26

[GoogleCodeExporter]

After some thought I would be happy if you made this a low priority feature 
request :-) I'll do some more investigation and hard code some values into the 
grabber myself to see how successful the idea is. Others may want to comment if 
they see any value in this idea. It would be an advanced feature used probably 
only by me!

Steve 

Original comment by sireland...@gmail.com on 22 Aug 2013 at 4:34

[GoogleCodeExporter]

Hi,

I would appreciate such feature as well! In my setups I also can see some 
"floor" values in the reading of my transmitter/clamps. The IAMs however are 
more accurate.
It would be nice to have such possibility for calibration.

But as Steve said: Only a nice to have...

Cheers,

Norbert

Original comment by ngorza...@googlemail.com on 22 Aug 2013 at 5:24

[GoogleCodeExporter]

[deleted comment]

[GoogleCodeExporter]

The floor would definitely be a good feature. But I would definitely "not" want 
the 'floor' subtracted from my generation values. 

With my 2nd EnviR using COSM via the CurrentCost Bridge, I am able to set rules 
in the settings page. 

I have a rule that is "if (out && power < 80) power = 0; power *= 1.02;" so if 
my generation is <80W then it = 0W and it multiplies my power value by 1.02 and 
that keeps things reasonable accurate.

I once did a blog post on the "sleeping" consumption of PV Inverters here >> 
http://wotid.com/blog/night-time-sleeping-load-consumption-of-my-grid-connected-
inverters/

Original comment by wot...@gmail.com on 24 Aug 2013 at 12:15

[GoogleCodeExporter]

Original comment by lalelu...@gmail.com on 19 Apr 2014 at 9:40

• Added labels: Type-Enhancement
• Removed labels: Priority-Medium

[GoogleCodeExporter]

Moved to github
https://github.com/lalelunet/measureit/issues/6

Original comment by lalelu...@gmail.com on 25 Jul 2014 at 8:29

[GoogleCodeExporter]

Not sure what to do with this..  :/

Moved to github
https://github.com/lalelunet/measureit/issues/9

Original comment by lalelu...@gmail.com on 25 Jul 2014 at 9:29

• Changed state: WontFix