Hey, sorry I meant https://www.sparkfun.com/products/8630

Hey, I was wondering if PIR Sensor like https://www.sparkfun.com/products/8630 will be able to detect movement via milk plexiglass? I would like to detect direct contact with plexiglass.

Do you have decoupling caps on the shift register Vcc pins (0.1uF cap from +5 to Gnd near the Vcc  pin)?

You could also look at terminating the clock line to clean it up.
http://www.fairchildsemi.com/an/AN/AN-393.pdf

Yes I do have decoupling, on power line 100nF, 1uF, 10uF. Also on the 595 chips between vcc and gnd 100nF just on top of the register.
By terminating you mean for ex. from last clock 10k resistor to gnd?

On this picture Digital 0 is the clock signal and Bus is the data signal? What's the sample rate of your USBee? More than 10MS/s? Doesn't look that bad to me. From the speed I'd guess you're using the hardware SPI, aren't you?

Can you define "noise problems"? How do these show up?

Both signals are clock, one is "analog" reading the other is digital. Usbee runs at 16mbps.

http://m.youtube.com/#/watch?v=SR9LhPwdWqg this is how it looks like. There should be one triangle lit up at one time.

And yes its hardware SPI that ShiftPWM uses on Mega its 52,51 and 8 for latch

Hello,
I am using arduino mega 1280 with shiftpwm library to run couple of shiftregisters with uln2003 that drives high power leds. I had some noise problems with >2 registers connected. I suspected the CLK signal so I disconnected all the registers and plugged usbee logic analyzer straight into the clock pin. The latch and data signal looks good (probably because it's lower frequency), but the clock signal has lots of saw spikes here is image of it http://masz.in/spi_shift/clock%20signal.jpg
The clock is running @ 4Mhz. I guess that the longer cable the worst signal this is probably why the more registers i add the bigger noise i have. Do you have any idea how to resolve this issue? Schmitt Trigger? Low Pass/High Pass filtering? Help!

1) yeah thats true, i meant 4051!
2) Like i said i can read with no problems at all signal from piezo, and actually the signal is not that short duration, because the piezo resonates for some peroid of time...

i have this mega version of arduino, and i plugged all of them in, and had the same results like i said, i could recive the signal, but it was affecting all the rest of the analog inputs, this is why i considered using 4051 because I was expecting it to have some built in stabilization etc things inside.
Like I said I don't have a problem with reading the signal from the sensor, just one sensor seems to affect the rest of sensors (analog inputs actually)

Hey I am creating a device that will be attached to regular Drum Kit. The setup is quite simple piezos with 1M resistors are plugged into 8051 and from arduino i read each value from the analog input. Everything is kind of straight forward cause I can read from the piezos values, but what I have noticed is that when i hit one piezo, the readings in other inputs are affected as well, and the values are high enough so I cannot from code really say which one was hitted (because I don't really care about what the values exactly are, just one hit). For me it seems that all the line of piezo's connected together affect the rest of the inputs somehow.
I guess I screwed up something with the piezo connection.

Thanks for any kind of hints!

oh and here is the schematics diagram for my connection setup
http://obrazki.elektroda.pl/2644224300_1302877364.jpg

hey guys,
I figured out how to make it using bc-337 transistors. I will put schematics later on !!
thank to you all!

hello,
I become very worried, after the last 3 posts, i will use these transmiters(http://www.laro.com.pl/pdf/hm4100f-5v.pdf) and these 595 ( http://www.nxp.com/acrobat_download/datasheets/74HC_HCT595_4.pdf ) and I started to worry if 595 will handle 8 of these transmiters, can somebody help me out and check if it will switch, with 1 transmiter( because i have only one at the moment ) and 7 leds, it works perfectly with no problems, but i am worried if 10mA will be enough? if not, can i use a capacitor to help it to switch? or it will flicker on/off, when capacitor is loading and releasing the current? please help we have only 2 days to finish this project...

THANKS!!

btw. my transmitter has H in the name so it's 200mW

Thanks a lot, i figured how to connect 4 registers, i wrote a small app in c# that controlls all the leds, later to support displaying jpeg sequence animations. later on i will replace the leds with transmiters.
I will upload my progress on this 15x15 bulb screen...

to admin: sorry could you move this topic to hardware:interferencing, i made a mistake making it here

thx

that's good, do i need an extra capacitor to handle the second pair of registers?

i wanted to supply current to those chips outside of arduino, from power supplier. How  big delay would it be with 4 595 chips on 3 pins??, because this  transmiter switche have about 10ms delay before they switch on so maybe little bit more delay would not make difference?.

Hello,
I am new to this forum so i hope that you can help me out guys.
I tried to find but i couldnt, informations about how many shift registers (595) you can attach to 3 pins on arduino, i found only examples for 2 registers, and i was wondering how many outputs can i get... what i am trying to do is, to control through serial, light bulbs making a big screen of them(and play a pong on it or something ), and switch them on and off using a transmiter that closes cuircuit on +5V (logical 1) and opens on 0V, it is a simple electromagnetic switch. I figured out how to control 80 bulbs with 2 registers on each 3 pins, so i could get 80 bulbs. I was also thinking about Max7129 but it works fine only with led matrixes because it refreshes in about 50Hz so human eye can't see that at the moment not all led's are blinking, but in this situation i need to keep the 5V all the time if i want to make the bulb light...

thanks for any help!

this is what i see, when connecting arduino after com dissappeared