Power Drain Sensor

sv1cox · 09-24-2008, 11:33 AM

FB received and is an amazing piece of hardware for its $$. Thanks!

The software till you got the feeling how things work (thanks to the YouTube vids) is very usable and flexible. My skin is allready ready.

BUT i have problems with the power mtr sensor (OS: Vista).

Using the supplied with the soft skin i can see random values on the first 2 inputs and steady 0 to the others, no matter on what pins i connect the sensor.

I find the rigth orientation of the sensor's plug from the start, no inverse connections. 5v on pin 1 on the sensor.

i put a 2A load on it and tried all the ports, no change at all. BTW: analog inputs pin 1 is near the digital pins?

Any ideas?

thanks in advance
Panos, SV1COX

greenman100 · 09-24-2008, 02:17 PM

Can you take a screen shot of the sensor connected, and the virtual brain option enabled in MDX?

sv1cox · 09-24-2008, 03:10 PM

i didnt really understand what is that about: "and the virtual brain option enabled in MDX?"

but here are some screenshots:

do you mean you need a photo from the board with the sensor connected too?

thanks again
Panos

h3rk · 09-24-2008, 03:15 PM

In the configurator, there is a little ladybug icon up top. click on it and you will see an option for running MDX in debug mode, one of the further options is to enable 'virtual' brains for any brain you have defined in the skin (or via configurator-same thing). Select debug and that option and save, and the next time you run MDX you will see the virtual brain that he's talking about.

screenshots are broke.

sv1cox · 09-24-2008, 03:43 PM

ok , got it, thanks.

2.5V or ~62 (X25) with no load on pin 9 (port 8?).

Panos

greenman100 · 09-24-2008, 03:52 PM

That's perfect, the sensor should be at 2.50 volts with no load.

How about a 10 amp load, and retake the screenshot?

sv1cox · 09-24-2008, 03:57 PM

10Amp???? no i can not do that, actually i need to monitor a load with a peak around 3Amps, now i can load it to 2A is that sufficient?

Panos

greenman100 · 09-24-2008, 03:59 PM

sure, do that, but it's rated for 50 amps, so full scale at 50 amps is Vnominal + 2.5 volts. Thus, you will only be at 2.15 at your 3 amp load - pretty low resolution.

sv1cox · 09-24-2008, 04:11 PM

aha i see, so the preconfigurated Current Sensor Function is out of date? (Vinput X 25 = A) ??

i have to change it to: [Vinput - 2.5] X WHAT?

what is the value of Vnomimal please? 5V?

i will do tests with the new function and i will report tommorow (around midnigth here now).

Can you confirm me that pin 9 is port 8 please?

thanks again and congrats for the excellent product and suport.

Panos

greenman100 · 09-24-2008, 04:16 PM

(Vinput-2.5)/.05 = amps

What do you mean about Pin 9 and Port 8?

sv1cox · 09-24-2008, 04:27 PM

On "Analogue Input" i choose Port=8 , on debug window i can see 2.5V on Analogue Input #9 so

where should i connect the sensor ?? now it is on the 9th holder counting from the side of digital pin's holder, that is i mean pin 9. is that Port 8?

Panos

sv1cox · 09-26-2008, 01:19 AM

ok from me it was [Vnominal - 2.5] X 25 and i can read the rigth value now.

BUT it takes 6-8 secs to read the end value on the text label. I mean i can see the amperage increasing on the text label to the maximum (rigth) value (while i can see the end value on the multimeter) and it takes up to 8 secs.

is it normal?

Panos

h3rk · 09-26-2008, 01:45 AM

that might be auto your "auto averaging" setting. It's a property of the input. and it's proabably set too high. I'd try setting it to false for now, or taking the value to 0 or really low.

sv1cox · 09-26-2008, 05:00 AM

yes you are rigth, but without averaging i have values changing +- 100mah.

I understand that i have to find an acceptable balance with some trials.

thanks agn.

greenman100 · 09-26-2008, 06:41 AM

Quote: Originally Posted by sv1cox

yes you are rigth, but without averaging i have values changing +- 100mah.

I understand that i have to find an acceptable balance with some trials.

thanks agn.

this is because you are using the sensor to measure such a small load. electrical noise is picked up, as it only takes 0.005 volts of noise to register as 100ma.