Show Posts
Pages: 1 ... 3 4 [5] 6 7 ... 40
61  Using Arduino / Sensors / Re: Measure distances in mm on: October 10, 2012, 01:17:50 am
A webcam to measure thicknesses??

yup - u would need to do some image processing...
the machine parts (in the background) should have a much different color than the wood pieces...
how fast do those pieces pass the sensor? less than 25Hz?
62  Using Arduino / Sensors / Re: Measure distances in mm on: October 09, 2012, 05:15:17 pm
nope
not capacitive but optical...
or is it impossible to look from the side?
63  Using Arduino / Sensors / Re: Measure distances in mm on: October 09, 2012, 03:32:37 pm
what about a webcam (properly affixed with screws or so... connected to some stable USB box... like an OLinuXino...) that looks at the piece from the side?
64  Using Arduino / Sensors / Re: Using CST-1020 on: October 08, 2012, 01:07:47 am
for the voltage i saw a transformer here, i think...
http://arduino.cc/forum/index.php/topic,93779.0.html
http://openenergymonitor.org/emon/
65  Using Arduino / Sensors / Re: Using CST-1020 on: October 07, 2012, 02:42:12 pm
yay!  smiley
66  Using Arduino / Sensors / Re: Using CST-1020 on: October 07, 2012, 09:19:24 am
what if u use a variation of "average mean", that uses absolute values?
sumi=1n  (ai)/n
that would almost give u the wanted result...  smiley

EDIT: oops - that would not really help (just 10%)... lol - sorry - i have no idea anymore what could cause that error...

r u sure ur oscilloscope is sufficiently accurate?
although errors of 60% would b funny...  smiley-lol
67  Using Arduino / Sensors / Re: Using CST-1020 on: October 06, 2012, 08:09:27 pm
uhm
why do u take the RMS value (it contains square values)?
http://en.wikipedia.org/wiki/Root_mean_square

i think the arithmetic mean would b the right value...
http://en.wikipedia.org/wiki/Arithmetic_average#Arithmetic_mean

have u seen this:
http://arduino.cc/forum/index.php/topic,125952.0.html  ?
68  Using Arduino / Sensors / Re: Using CST-1020 on: October 06, 2012, 06:08:45 pm
1.
ok - that sounds safe...

2.
i c

3.
ok - then it should work... how many measurements do u take? since it is AC, the voltage changes quite rapidly and strongly, i guess...
69  Using Arduino / Sensors / Re: Using CST-1020 on: October 06, 2012, 05:12:47 pm
1.
how do u get a mainspower plug through that tiny hole?

2.
that sparkfun sensor can b integrated easier, i guess...
one just snaps it on the mains power line...

3.
possibly u just measure the reactive power?
i have no idea how that sensor works, when there r 2 wires with the same current (just the direction is the oposite)...
i think u should wait for the high voltage experts... they should b here within a day... smiley
70  Using Arduino / Sensors / Re: Capacitive sensor: sensitivity problem on: October 06, 2012, 07:30:29 am
did u try this:
http://en.wikipedia.org/wiki/Capacitance_multiplier ?

could it b that u pick up a lot of 50Hz noise?

did u try to make a shielding below and around the sensor plate?
some grounded metal foil should suffice...
71  Using Arduino / Sensors / Re: Using CST-1020 on: October 06, 2012, 07:26:01 am
1.
coils/capacitors have logarithmic/exponential curves...
http://www.falstad.com/circuit/e-induct.html
http://en.wikipedia.org/wiki/Inductor#Inductance_formulae

2.
how do u plan to make the primary side of that sensor?
it seems to b a little bit dangerous for my taste...
do u know an electrician?
72  Using Arduino / Sensors / Re: Using CST-1020 on: October 06, 2012, 01:28:44 am
Hi Nuno!

RL seems to be outside of the CST1020 according to the picture...
Let RL=100, then appr. 100mV on RL translate to 1A... 200mV to 2A...

I hope u took sufficient care to uphold proper insulation...
How did u do it?

Bye
73  Using Arduino / Sensors / Re: Anyone know what is Temperature Sensor + Relay Module for Arduino for? on: October 06, 2012, 01:02:50 am
it seems like it is controlled by temperature...
there is no other way to turn the relays on or off...
the temperatures can b controlled by the potentiometers...
74  Using Arduino / Sensors / Re: GROVE I2C Touch Sensor with Arduino Nano on: October 05, 2012, 02:28:55 pm
there is a I2C library:
http://www.arduino.cc/en/Reference/Wire

the I2C pins of the arduino nano r: pin 4 and pin 5
http://arduino.cc/en/Main/ArduinoBoardNano

have fun...  smiley
75  Using Arduino / Sensors / Re: Is there a mature and accurate way to log remote temperature to computer? on: October 05, 2012, 02:25:39 pm
MacGyver rulz...  smiley-cool
Pages: 1 ... 3 4 [5] 6 7 ... 40