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1  Topics / Device Hacking / Re: 100ns pulses on: July 04, 2013, 01:31:19 am
Yes, Manchester Encoding.
2  Topics / Device Hacking / Re: 100ns pulses on: July 01, 2013, 02:34:15 am
If I can guarantee to capture one measurement of each pulse, then I would be satisfied. Messages are 34 bit and that's what I want to capture and then process. First step is to be able to capture the pulse, as they are very fast. I'm wanting to work toward creating a type of network analyzer to search for certain messages and then activate an LED as an indicated that a given message has come across the line. That's my overall aim.
3  Topics / Device Hacking / 100ns pulses on: June 28, 2013, 11:43:58 pm
I want to tap into a set of serial data that is transferred in binary pulses of 100 nanoseconds of width. Can Arduino catch this signal, or is the signal too fast? What can be recommended?

The pulses swing from +3volts to -3volts, with each half having a width of 50 nanoseconds.

Ron
4  Forum 2005-2010 (read only) / Interfacing / Re: 7 Segment Display using SPI on: June 20, 2010, 03:47:46 pm
example code works for me! Now time to tweak...
5  Forum 2005-2010 (read only) / Interfacing / Re: How do I measure 8000 volts with Arduino? on: June 09, 2010, 02:23:35 am
another one: radio tuned to a blank AM station. The RF noise generated by the pulsing high voltage should be detectable; this is essentially how a lot of tachometers get their signal for measuring engine rpm. I know you want the actual measurement of the voltage, rather than simply know if its there. You can spend some time and creativity and find a way to calibrate any sensor you make.
6  Forum 2005-2010 (read only) / Interfacing / Re: How do I measure 8000 volts with Arduino? on: June 09, 2010, 02:15:32 am
You could have a lot of 'fun' with this. My first thought was using a static electricity meter- I recall a physics professor having a very simple device that was two metal rod joined at one end with a pin to allow the rods to swing. The rods were thin and light weight, and once electric charge flows onto the rods, they will want to repel each other and will swing some distance apart. You could put a piezo strain sensor to measure the force of the rods repelling as a function of voltage. You could also experiment with taking two metal plates to make your own capacitor, and install a piezo strain sensor to measure the force between the two plates. Put some thin plastic, or rubber, or wax paper between the plates (I suggest Aluminum).

Another type of idea. I believe that this voltage sensor would not need to refresh often....maybe somewhere between 4 times to 24 times a day is good. If this is the case, then you could setup a bank of capacitors and diodes to handle the voltage to charge at the high voltage, and then discharge at a much lower voltage. Look into 'voltage multipliers'.

You could maybe most easily use a shunt that is switchable from programming in Arduino- say activate the shunt once an hour and then read the voltage on the line using common meters. Use long grounding rods into the soil for both the electric fence ground and another for the shunt ground. The voltage will fluctuate some with weather and moisture in the soil.
7  Forum 2005-2010 (read only) / Interfacing / Re: SPI Primer on: June 04, 2010, 12:35:56 am
Here is a link to the data sheet for the 4 digit display that I am trying to link via SPI:

http://www.sparkfun.com/datasheets/Components/LED/SFE-0012-DS-7segmentSerial-v3.pdf

This display has an ATMega integrated on the backside...it seems that really I'm trying to communicate from one ATMega to another. I am a bit new to the Arduino platform, and completely new to SPI. My current goal is to have the display show a time...say 10:30 . I'm thinking I need some good examples of SPI projects, if not direct advice for using this display. Thank you for your reply.
 :o
8  Forum 2005-2010 (read only) / Interfacing / SPI Primer on: June 03, 2010, 10:41:36 pm
I need to get my feet pointed correctly with some good examples of using the SPI protocol with Arduino. I was told to include the SPI library into the sketch, though the examples I find do not include the SPI library...What is the reason for this? :-? :-?
9  Forum 2005-2010 (read only) / Interfacing / Re: Connect 2 arduino's with wires on: June 03, 2010, 12:25:20 am
Are you having Arduino control a damper to each room, to control the air flow?
10  Forum 2005-2010 (read only) / Interfacing / Re: Sparkfun 4 digit 7-segment LED display with SPI on: June 02, 2010, 08:17:58 pm
Just looking for a SPI primer. Please give advice.
11  Forum 2005-2010 (read only) / Interfacing / Re: Sparkfun 4 digit 7-segment LED display with SPI on: June 01, 2010, 10:53:58 am
Is there a set of examples demonstrating the programming to use SPI?

I know that the SPI library should be referenced, though I don't see that in some of the code posted for other devices using SPI. I am trying to communicate in one direction, from Arduino to a 7-seg LED display.
12  Forum 2005-2010 (read only) / Interfacing / Sparkfun 4 digit 7-segment LED display with SPI on: May 30, 2010, 05:29:37 pm
Hello Arduino Community,

I have two of the SPI 4 digit displays from Sparkfun, and I am trying to get them to interface with my Arduino Duemilanova ATMega328. The info I have found on SPI is not clear. My aim is to have the displays show the time. I know to use pins 10, 11, 12, 13 on the Arduino board, and I have one display connected now. I also imported the SPI library... where do I go from here? Can I type into the serial monitor and have numbers displayed that way?   I appreciate any help.

Ron
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