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61  Forum 2005-2010 (read only) / Interfacing / Re: LED Matrix 16x64 on: January 13, 2011, 09:50:35 pm
You can pwm the 595

Videos are good.
62  Forum 2005-2010 (read only) / Interfacing / Re: Rotary encoder controlled solenoid on: January 09, 2011, 08:28:56 pm
Link to the hall effect part and to the solenoid and show your wiring...
63  Forum 2005-2010 (read only) / Interfacing / Re: Help With BBQ Smoker Temperature Control Project on: December 05, 2010, 05:23:06 pm
This seems adequate. The black has been cut and wired to the SSR. The GFI is a nice touch. The crimps on the spade lugs look good.

I would suggest a barrier over the 3-30V input when you've installed wires to it. Also use a separate opening for those love voltage wires in case they break and touch AC or the AC wires break and touch them. Dress them away from any AC outside the box.

I think the heatsink is outside the box? If so I believe you should tie that to ground just in case you get a catastrophic failure and one of the AC lines break and touch it or the SSR fails in a way the manufacturer will swear is impossible.

The most common failure I see on industrial controls is a wire breaking and falling where it should never go if dressed and tied down properly.

On commercial and consumer equipment low voltage inputs and outputs; transorbs are commonly found to keep high voltage transients and induced currents out of them.  If you use them use a fuse in series.

64  Forum 2005-2010 (read only) / Interfacing / ili9320 on: October 26, 2010, 09:29:34 am
65  Forum 2005-2010 (read only) / Interfacing / Re: Cheap Relay Needed for my project on: January 09, 2011, 03:05:51 am
We call it RatShack for a reason now.

Relay 101

Some symbols for more complex relays.

You need to specify exactly what you're doing. Provide your code and show how you plan on wiring it. I can't see where you know how to wire a relay for use with an arduino or other digital output.

66  Forum 2005-2010 (read only) / Interfacing / RS-485 design article with multi drop on: January 06, 2011, 10:11:30 pm

This is nice if you can get it but I believe there are now pin compatible alternates by other manufacturers.
67  Forum 2005-2010 (read only) / Interfacing / Re: Reading Temp Sensor from Car Engine on: November 25, 2010, 10:59:48 am
What you want is ODBII

The OBDuino can read that and more.
68  Forum 2005-2010 (read only) / Interfacing / Re: Decoding Radio Control signal pulses on: July 08, 2010, 12:27:52 pm

PCM is really complex. The link has limited information but allows comparison of them visually with two oscilloscope screen captures.

The DIY UAV looks interesting
69  Forum 2005-2010 (read only) / Interfacing / Re: Do analog pins really have pull-up resistors? on: January 05, 2011, 05:41:57 am
The Japanino has a soldered on atmega chip. Smoke that and you'll pay an ubergeek to solder one with a boot loader on unless you're capable of doing that yourself. Also problematic is programming the chip yourself since it's a quad flatpack. You can solder in the missing ICSP pins on the Japanino and buy another Japanino or Arduino to program the chip with.

This is why the Arduino is socketed, you can fry the chip during development and just replace the socketed part. The ICSP pins are present so if you have another Arduino you can just program it.

70  Forum 2005-2010 (read only) / Interfacing / Re: How do I connect a relay? on: December 09, 2007, 09:03:40 am
Believe it or not I have exactly that relay. You made me remember I had one.

First get that LED blinking. Make it blink!

Then remove the resistor and LED and replace it with the 3-32v control input of the SSR, be sure polarity is correct.  Negative to ground and positive to the digital output.

I have an old clamp on lamp that IMHO sucks, the clamp is useless. So I cut the hot lead and stripped the two ends.  Then I hooked one lead of the hot lead to the AC terminal on the SSR and the other lead went to the other terminal. Polarity does not matter.

I plugged the lamp into a socket and it merrily blinked a CCFL bulb.


It's bad to blink Mr. CCFL as he does not like this and I drove him to suicide!
AWWWWW Poor Mr CCFL died in the name of science!

But incandescents work just fine. smiley-wink

Earlier I managed to extend the Arduino's IO ports so that I have 16 extra minus the four control ports. In general I have 12 (though with some program trickery I can recover two of those four for other uses). With 16 SSRs I can have some fun with any AC powered device. smiley-wink

71  Forum 2005-2010 (read only) / Interfacing / Re: How do I connect a relay? on: December 07, 2007, 03:50:21 am
Woah I didn't think of that having 240vac in there.

Don't breadboard the AC with the DC use another board, preferably a insulated terminal board.  Or keep the arduino connections off the breadboard.

The SSR needs 3 -32 vdc and not much current 3.4ma at 5vdc so the arduino will do fine.  DC ground goes to terminal 4 and the arduino digital output goes to terminal 3, you can pick any digital output. If you use the blinking led example you can watch the light blink when you power on the arduino.
72  Forum 2005-2010 (read only) / Interfacing / Re: How do I connect a relay? on: December 03, 2007, 07:54:29 pm
+1 digger
You'll need a SSR for the specific DC voltage you're trying to control.  If all you're controlling is +12V you can just use a transistor and turn it on and off with the arduino, provide an external +12V to the transistor tie the grounds together and you're done. If the transistor mentioned in the following article is not enough then a mechanical relay is your next cheaper step.

High current loads

73  Forum 2005-2010 (read only) / Interfacing / Attiny13 or Attiny2313 as watchdog. on: January 02, 2011, 08:37:14 pm

You can go minimalist with it and use the 2313, It has six I/O lines so it can monitor 3 units and activate 3 resets. Of course it can do more but I would use this or any other part in lieu of any maxim watchdog product. I'm done with maxim for those.  I'd suggest the automotive rated one for this part but earlier you mentioned finding out if this had all been done before and that would be something to check on first.

74  Forum 2005-2010 (read only) / Interfacing / Re: Possible Ways to Run Health Checks for Arduino on: December 31, 2010, 03:42:12 pm
You looking for a triple modular redundancy it actually takes more than three units.

Standard microcontroller watchdog integrated circuits will read a pulse from the microcontroller and this resets the watchdog counter to zero. You can do that with a dedicated circuit or if you need some repeatability and precision I'd do it with a microcontroller. See the rant below.

Since the Arduino was probably not built with the highest rated parts for military and aerospace applications and not made to class three  soldering specifications you are constrained in testing units to see if they have some chance of surviving.

One of the simplest things you can do is to us one of the Arduino variants that use no socketed parts and then conformal coat the board excluding connectors or areas that need to be soldered later.

The other is to run them across the temperature range they will be exposed to and see if they fail and if possible make corrections to the board or supply environmental controls to keep the temperature where they can survive. Thermal cycling usually kills solder connections but can kill components not rated for it.

The voting system can actually be a rigorously tested Arduino. It can also act as a watchdog for the other systems. You'd want an external watchdog on it to reboot it if needed. I'd be tempted to use an ATTINY as a watchdog rather than the available dedicated watchdog integrated circuits. That is due to the following experience.

.rant. I've worked with the Dallas external watchdog integrated circuit. DS1232. I can't spit on it hard enough to kill the engineer that built this piece of *t.  It has no consistency across temperature, it has no consistency between parts and if you get one batch to work the next batch you buy might not. All of the clones made by other vendors of this chip have the exact same problems. That was their DIP8 part, their surface mount part is just as bad when I tried it. Instead of redesigning the system or touching the firmware which would cost us 10s of thousands of dollars we hand select parts that work. ./rant.
75  Forum 2005-2010 (read only) / Interfacing / Re: How would i use my android phone w arduino? on: January 01, 2011, 11:52:25 am
Shades of Zenith! One of the first remotes was a 'pinger' or 'xylophone' remote. A mechanical remote that would strike tuned metal bars which would operate power, channels and volume.

Inside the TV was a microphone that was amplified and fed several tuned circuits. When a tone came in it activated the corresponding circuit which would activate the function needed.

It's draw back was that you could jingle your keys at it and have it go nuts. :-D

I would suspect you'd want to generate sequential tones of long enough duration that the arduino could decode them. That would help cut down errors. I do not think the arduino can easily decode dual tone multifrequency codes but they would make errors less likely.

This would make it slightly easier.
DTMF circuit

This is a DTMF shield for the arduino

It would be up to you to stick a microphone and a mini audio amp on that to pick up the tones and have the arduino decode them for use.

You would also want an app for the android to generate the tones loud enough to be decoded. I can get tones out of mine but they are not from the main speaker.
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