ANy Mathmaticians out there?

[mustangcoupe]

It was way to early this moerning to be looking at your numbers or I was still sleeping... -30 is closer to 0 then -100... so with that said I just got home from work and had a chance to do some math today and I know it dosent sound right but the math works out to

%	uV	dBm
0	2.238721	-100.0000005
10	707.7219279	-50.00274696
20	1415.443856	-43.98214705
30	2123.165784	-40.46032187
40	2830.887712	-37.96154714
50	3538.60964	-36.02334688
60	4246.331567	-34.43972195
70	4954.053495	-33.10078616
80	5661.775423	-31.94094722
90	6369.497351	-30.91789677
100	7079.458	-29.99999981

.01% =about  0.707721928 uV

so I came up with the following.........

signal level in dB converted to %

ex. -86

10^((-86+107)/20)=11.22018454

(11.22018454/0.707721928)*.01= 0.15853945 aprox percent


so your formula would be

((10^((YOUR NUMBER IN dB+107)/20))/0.707721928)*0.01

 

[JohnWPB]

Hey, thanks for the help! You should never try to do math like that when you first wake up! Hell, I cant do it when I am fully awake! hahha

Well I thought that was it for a few minutes, I plugged in 30 and it reported 100%. Then when I actually plugged in my variable into the script, I noticed it was spitting out some strange numbers I calculated the "center point" between -30 and -100 (-65) and used that to test with.

Here are the 2 lines of code I used to test (This was written in AutoIt script, very similar to VBScript)

$signaldBP=((10^((-65 +107)/20))/0.707721928)*0.01
$signalPercent = Int($signaldB) & "%"

It reports 1%

Knowing that -30 = 100%, and -100 = 0% the halfway point between -30 & -100 is -65.


-30 = 100%
-65 = 50%
-100 = 0%

So in the above 2 lines of code, plugging in -65 should return 50%, but it is returning 1%.

EDIT:

Looking at your chart further, I think I see why, I just don't know how to fix the equasion based on it

% uV dBm
0 2.238721 -100.0000005--------------v
10 707.7219279 -50.00274696-------^ -50 Point Jump between line 0 and line 10


20 1415.443856 -43.98214705----------v
30 2123.165784 -40.46032187
40 2830.887712 -37.96154714
50 3538.60964 -36.02334688
60 4246.331567 -34.43972195
70 4954.053495 -33.10078616
80 5661.775423 -31.94094722
90 6369.497351 -30.91789677
100 7079.458 -29.99999981 ------------^Only 20 Data Point jump between like 10 and 80

 

[mustangcoupe]

Looking at your chart further, I think I see why, I just don't know how to fix the equasion based on it

dB is not a linear world.... so your example of -65 =50% would not be correct, did you move further away and confirm that they are true dB numbers? Or are they doing some sudo averaging and reporting between -30 and -100........ what software are you getting these numbers from? maybe I can play with it.

 

[JohnWPB]

Looking at your chart further, I think I see why, I just don't know how to fix the equasion based on it

dB is not a linear world.... so your example of -65 =50% would not be correct, did you move further away and confirm that they are true dB numbers? Or are they doing some sudo averaging and reporting between -30 and -100........ what software are you getting these numbers from? maybe I can play with it.

Its a pretty lengthy AutoIt script, that depends on a lot of other stuff pieced together here

Yes, I did move the WiFi device closer and further from the router.

If I move it just 2 feet away, the db drops to just -38 (just 8 points) but the percentage from the script above drops all the way down to 2%.

As mentioned, I wish I would have never even mentioned the dB thing as I just want a liniar scale that shows 0 to 100% for values from -100 to -30.

 

[DeLicious]

a linear equation would be y = (10/7) * (x + 100)

for x = -100, y = 0
for x = -30, y = 100

 

[JohnWPB]

a linear equation would be y = (10/7) * (x + 100)

for x = -100, y = 0
for x = -30, y = 100

Cool, that did it! Thank you very much! I just had to put a check in if >100 then = 100 as I was rarely gettng 101% and such when I was on top of the wireless router. This basically is for my CarPC skin, but I use the same interface on the touchscreens in the house. The front end is Road Runner, and has a COM interface, so bidirectional communication between Road Runner and Home Seer is a snap. So something as simple as If SignalStrength < 10 then HS_Send ("NetworkProblem"), which can then have HS speak something like "Network problems, please check the router" or trigger any type of event.

Here is a capture just to let you guys know what this was all for

(The labels at the top for city and such are empty, as I do not have the GPS hooked up to this PC, as those labels will be removed for the 'House skin" )

 

[SnyperBob]

Ah, good ol' Road Runner

Are you going to release your new skin?

PS - Ever since my work blocked MP3car on the firewall my life has been incomplete Sucks, because it was auto-blocked just because it has mp3 in the site name

- Snyper Bob

 

[BraveSirRobbin]

Nice job Delicious!!

Sorry John, I got hung up on the dB thing also.

FYI, there actually IS a How-To on doing this HERE, (linear equation part) though one would not guess that would be of any help with that title.

Glad you got it working.

 

[JohnWPB]

Yes, RR has become multi purpose for me, perfect for in the car, perfect front end for Home seer in the house.

Yea, I will be releasing the new skin in a couple of weeks or so. It has been coundless hours of work trying to get it all together. You can read about it in the DigitalFX thread. Warning: The thread is now the longest thread on MP3Car, at just over 3,000 posts! So plan for some serious reading LOL