power meter for 1prebis7 - beta testers wanted

[Hamburger]

maybe a tossup of the 100U or 100B variants?

[Hamburger]

for x100u specsheet says
40mV/A sensitivity and
12mV noise on the output pin. That is 12/40A = 0,3A noise or resolution.
With arduino promini 4,9mV / integer step on analog in
that should leave the two lowest bits filled with noise.
So maybe just zero out two lowest bits? Would save you the trouble with the averaging too.

[KaiK]

I am pretty shure (as I have the Unidirectional 100U) that is works like this:

Bidirectional (100B): 0A -> VCC/2
Unidirectional (100U): 0A -> 0.6V (or another value near 0V but not equals 0V).

[jevermeister]

Ok,
found it, I was using the wrong datasheet

I now have the correct one, which is saying 0,6V for 0A.


Thank you Kaik and Hamburger!!

Nils

[IceWind]

Did anyone tried to use one of these?

https://www.sparkfun.com/products/9028

I was curious to try the current meter features in the Mwc and as I have this one it seemed a good choice.
Good thing is I can get both Voltage and Current from it.

[jevermeister]

I thought about buying one of them but I ordered a dedicated sensor. but if it delivers an analog signal it will definetely work.You can set the parameters to every output range and stepwidth.

nils

[IceWind]

Couldn't wait for an answer, went ahead and added code to the MWC to support it.


Yes, it outputs a analog value for both the Current and Voltage. 0-3.3v.
Using with 5v will loose a bit of resolution but nothing problematic, tomorrow I'll see if all the calculation are correct.
And I'll need to play with those values to get it reading correct.