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16  Using Arduino / Motors, Mechanics, and Power / Re: 12v DC pump/ SSR relay on: May 07, 2014, 06:41:09 am
I believe a SSR is essentially a triac. This is from a Wikipedia page: "Once triggered, the device continues to conduct until the current drops below a certain threshold called the holding current." - Scotty
17  Using Arduino / Motors, Mechanics, and Power / Re: Gearmotor program on: May 07, 2014, 06:33:51 am
Welcome to these forums. Help for you is available but you have to help yourself first. You must do some homework on your own to gain an understanding of what to do to get yourself started in your endeavor. To do so, simply Google 'Arduino DC motor' and read. If you do so, you will then understand enough to allow you to proceed on your own, at least enough to ask specific questions. Your original post seems to request 'take my hand and do this project for me'. - Scotty
18  Using Arduino / General Electronics / Re: Figuring out some numbers for a mini pump on: May 06, 2014, 07:23:18 am
How often and for how long is the pump needed to be run? - Scotty
19  Using Arduino / Motors, Mechanics, and Power / Re: Stepper vs DC vs Servo on: April 23, 2014, 12:20:42 pm
Quote
Why not a stepper ?

Battery powered or not, it's just a waste of power to hold in position, especially if the panel is not in continuous use. Depending on motor size, cost for a stepper and driver may be an issue too . There is an abundance of high torque, low cost dc motor solutions. But nothing firm can be suggested until the OP provides us with more information on this project. - Scotty
20  Using Arduino / Motors, Mechanics, and Power / Re: Stepper vs DC vs Servo on: April 23, 2014, 06:35:43 am
My choice would be a dc motor with a worm gear drive. The worm gear drive would hold the position of what is being driven when the motor is not powered. Beyond that, more information is needed to make suggestions, i.e., what scale are we talking about (weight, size, etc.)?- Scotty
21  Using Arduino / Project Guidance / Re: Pulse to m/sec on: April 17, 2014, 06:29:16 am
Quote
Is that not  a slotted opto switch, in which case, it will not work at all with a SOLID disk!

This may completely confuse the OP. Although the disk is a solid, it is not completely opaque. In it's rotation, it will alternately block the IR from the opto interupter's emitter which will alternately swing the device's receiver output. It will work.

- Scotty
22  Using Arduino / Programming Questions / Re: Pulse train comparrison/matching on: April 16, 2014, 10:11:48 am
Quote
Are you saying that when there is no smoke detection there is no signal, and when there is smoke detection there is the signal you displayed above?

Yes.

Quote
Does the device also put put any other signals that you need to identify as NOT being a smoke detection signal?

No.
23  Using Arduino / Programming Questions / Re: Pulse train comparrison/matching on: April 16, 2014, 07:19:24 am
Thanks for responding, Gentlemen. Perhaps I've not been clear enough. My post is concerning only one event, a smoke detector going off, sounding an alarm.  The smoke detector is a type that, when it goes off, transmits an RF signal to other smoke detectors and they will also sound an alarm. The data shown represents the output of an RF receiver that has captured the RF signal when the smoke detector goes off. The RF signal, as viewed on a scope, looks like this:

The Pulsein function sees the low, short pulses as approximately 390usec and the longer low pulses as approximately 800usec.

The output of the receiver is fed to an input pin (7) of an Arduino. The code is below. One line of the data shown in the original post is what is seen, over and over, in the serial monitor.
Code:
/*
  PulseIn sketch

 */


const int inputPin = 7;   // analog output pin to monitor
unsigned long val;  // this will hold the value from pulseIn

void setup()

  Serial.begin(115200);
}

void loop()
{
  val = pulseIn(inputPin, LOW);
  Serial.println(val);


Does this clear things up? - Scotty

24  Using Arduino / Programming Questions / Pulse train comparrison/matching on: April 15, 2014, 03:48:11 pm
Hello Guys.I'm working on a home security project, having a text sent to me if certain events occur. One of those events is the  detection of smoke. I purchased a Kidde wireless (433Mhz) smoke alarm and am currently able to receive it's signal via a cheap receiver and was successful is using the Arduino's Pulsein(negative transition) to collect pulse data from the alarm. Below are 3 groups. Each group shows pulse width data for different user switch settings on the alarm.

I'm seeking advice on how to compare the incoming data to fixed data in a constant variable. The first number in each row below is the pause between signals sent by the alarm. I suppose that detecting the length of that first number would be the start of collecting data. I'm imagining that any pulse width between a range of say, 360-420 could be assigned a 0 and any pulse width of a range of 780-820 be considered a 1. When determined to be 0 or 1, could those bits somehow be arranged into a binary number? How would that be done? Afterward I could compare it to a binary number stored in the previously mentioned variable. I'm seeking a direction to go with the programming. Please suggest a good way to go about this. Thanks - Scotty

Code:
30147 380 392 388 1573 402 402 393 394 401 401 401 800 402 802 810 804 802 402 405 398 397 405
48734 373 389 389 1587 403 390 393 400 400 400 393 806 401 801 802 801 808 402 394 397 405 402
37169 382 394 382 1572 397 396 400 394 396 402 401 800 397 801 802 802 804 397 400 403 405 396

41406 373 400 397 1572 398 397 402 397 401 809 801 397 810 802 812 804 400 398 405 804
39944 367 396 397 1568 405 396 396 401 402 804 799 405 802 805 805 800 407 401 400 804
35690 376 398 390 1579 407 392 400 403 402 801 804 402 809 802 801 805 406 396 406 806

31026 384 397 397 1579 398 397 401 385 402 398 394 401 410 792 802 802 801 410 405 405 394 397
35777 376 398 398 1578 402 398 402 402 400 397 398 405 402 795 804 804 812 406 403 403 398 394
40726 368 397 397 1565 400 397 401 401 401 397 402 403 410 796 804 806 805 410 405 403 398 394
25  Using Arduino / Motors, Mechanics, and Power / Re: Motorized Valve on: April 13, 2014, 06:17:39 am
Does the rate of flow need to be controlled or will simple on-off suffice? - Scotty
26  Using Arduino / Project Guidance / Re: Guitar Pickup Winder on: April 04, 2014, 02:02:48 pm
Quote
How fast was the winding being done?
It wasn't very fast; perhaps 75RPM.

Quote
Perhaps the design should have a stepper that moves the entire winding assembly (pickup bobbin and DC motor) back and forth rather than the copper wire?
What would be the difference?

At the time I was thinking that having a piece to guide the wire onto the spool, located very close to the spool might eliminate the lag in changing direction but that would require having that position change relative to the ever increasing diameter of the spool winding. That was more work than I was willing to put into it.

- Scotty
27  Using Arduino / Project Guidance / Re: Guitar Pickup Winder on: April 04, 2014, 08:47:54 am
This project appealed to me a couple of years ago. I put quite a bit of effort into it but it was not an essential project so I decided to move on after not eventually getting it to work correctly. The problem I encountered, and did not resolve, was in changing the left/right direction of the wind. When the end of a layer of wind would come about and a direction change was initiated, the winding wire would want to linger at the end and build up additional layers there. After enough pull in direction change, it would move in the opposite direction but by that time the device pulling the wire would be significantly away from the end. When the wire finally 'obeyed' and did move, it would move way over to it's intended position, skipping over most of the wind from the previous 'end' to it's new position. After only a few iterations of layers, it was a mess of hills and valleys. I used these motors. - Scotty
28  Using Arduino / General Electronics / Re: IR sensor for arduino on: April 04, 2014, 07:56:24 am
I completed this project. To avoid false triggering, I pulsed the transmitter at 38kHz since the receiver is designed to 'see' that frequency. For the IR receiver I used this. For the transmitter I used this. The emitter is driven through a transistor who's 38kHz base signal is derived from a 555 timer. I had problems with getting an accurate frequency with the 555; it was very fussy about the external timing capacitor used. I was able to get a stable frequency using a high precision, low value capacitor. If I were to do it again I would use an Attiny85. No external components (except for decoupling) are needed, very stable, and it costs only about $.40 more than a 555. You would need to learn how to load code to it but that's no big deal. - Scotty
29  Using Arduino / Project Guidance / Smoke alarm detection on: April 02, 2014, 09:12:57 am
Smoke alarm detection is part of a home security project I'm working on. I'm seeking advice on using a 'local' microcontroller to  detect smoke alarm activation and sending a 'smoke alarm activated' signal to a 'master' Arduino. My initial thinking is to make use of the smoke alarms battery as a power source. Doing so, power conservation is a must. Although I've not investigated much, I'm pretty sure I can make use of 'sleep mode' of an Atmel AVR device on a DIY board using perhaps an Attiny85 or like device or using a smaller Arduino such as a mini or micro. Any thoughts on that?

There are most likely several ways to have the smoke detector wake up the micro controller. One that comes to mind is tapping off the alarm's escape light. Any other ideas?

What are your thoughts on what low power, wireless means of transmitting that detection to a 'master' Arduino is most practical? Line of sight is not practical.

All that aside, would it be possible to make use of Kiddie wireless (RF) smoke detectors?

Thanks - Scotty
30  Using Arduino / Project Guidance / Re: Arduino caliper on: March 31, 2014, 07:04:13 am
Rather than build a digital caliper with an Arduino, it may be easier to hack one of the cheap digital calipers and use an Arduino to read the calipers. This has been done by a member of these forums. Simply google "interfacing arduino with a digital caliper". How do they work? Google "how do digital calipers work?". - Scotty
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