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406  Using Arduino / Project Guidance / Re: 350Mhz RF Remote. I know there is 315mhz and 433mhz. on: March 08, 2013, 07:29:46 pm
oh, and make sure that you have the ground on the transmitter connected to the ground on the arduino. Otherwise, a high or low may not be valid voltage levels.
407  Using Arduino / Project Guidance / Re: 350Mhz RF Remote. I know there is 315mhz and 433mhz. on: March 08, 2013, 07:28:07 pm
ok, so you are using the RCswitch library with no modifications and have the data pin of the module connected to pin 2 on the Arduino?

You could connect an LED to this as well that will flicker when data is being received by the module. To check this with the Arduino, try a little sketch like this:

Code:
void setup(){
  Serial.begin(9600);
  attachInterrupt(0,test,FALLING);
}

void loop(){

}

void test(){

Serial.println("Pin went low!);

}
408  Using Arduino / Project Guidance / Re: How to decode this on: March 08, 2013, 07:10:18 pm
Thanks! I'll take a look.
409  Using Arduino / Project Guidance / How to decode this on: March 08, 2013, 07:03:41 pm
I have a device that is outputting the signal shown in the attached image.

The signal goes low for 3ms to start. Then a zero is indicated by high of 1ms and a low of 2ms, while a one is indicated by a high of 2ms and a low of 1ms. There are 8 bits in the signal. Then there is an approximately 9ms gap before it repeats as long as the signal is present.

Since I don't know when the signal will come in, I started by triggering an interrupt on the falling edge. Obviously this will trigger for every falling edge in the signal. So, I expect it to trigger every 3ms except during the gap of course. but what I am interested in is what happens during that 3ms.

This kind of thing has always been my weakest point and would love to learn how to do this.
410  Using Arduino / Displays / Re: How to read HD44780 LCD programmatically on: March 08, 2013, 06:28:18 pm
Well, that's pretty simple isn't it? I will add that in.

I haven't finished the code yet. Well, actually finished it, but having some issues with timing and haven't had time to work on it again since last night.

I see another post like this in the forum, recently. I am really curious what the purpose would really be. I can't think of any use I would have for it. I was thinking maybe to support input by a user, but you have to white the character to be displayed for the input anyway, so you already know what it is.

This is very low priority for me.
411  Using Arduino / Displays / Re: About LCD 1604 on: March 08, 2013, 06:18:45 pm
Still sounds far more complex than it needs to be. Why not just add whatever special commands also to the original code to be transmitted over bluetooth and decoded into a proper display. Seriously, as long as the OP has acces to the source code of the original Arduino, it seems silly to do all of this the hard way. Maybe it would make sense in a 'hack' type of setting, but I am assuming his first Arduino is running his own code.
412  Using Arduino / Project Guidance / Re: Help making something safer. on: March 08, 2013, 04:56:37 pm
Ever hold the ring and tip lines in your fingers when the phone rang? Not very pleasant. Also got myself on the flyback of a TV more than once.

I've even gotten shocked with full 120VAC more than once. The worst was a badly installed freezer. The old metal kind that had a self-defrost. Well, my dad put one in the garage and the water would pool up underneath it. When you stood in that and grabbed the door, it bit you pretty good.

But, alas, no burns. The only time I have ever been burned by electricity was while trying to fix a digital camera for my niece and I accidently ran my finger across the flash cap solder joints.

My Brother got burned while installing a car stereo once. His skin was sweaty and the power and ground laid down against his forearm. He ended up with a nice deep cauterized cut. Why he had the wires exposed and working on it while the ignition was on is beyond me.

The point being, there is very little danger here and IMO not worth whatever effort it takes to protect against it. The coils should be enameled wire in the first place, so they are insulated.
413  Using Arduino / Project Guidance / Re: Help making something safer. on: March 08, 2013, 01:45:23 pm
And to think that kids have put 9V batteries on their tongues for decades and nobody has died or even burned....
414  Using Arduino / Displays / Re: About LCD 1604 on: March 08, 2013, 01:20:10 pm
I'll ask the dumb question here... if you are in control of the original Arduino, why not just duplicate the output to the serial port and on to a bluetooth module in the code?

Something like

LCD.print(value);
Serial.print(value);

The two print statements are pretty much compatible with each other.
415  Using Arduino / Displays / Re: How to read HD44780 LCD programmatically on: March 08, 2013, 01:04:46 pm
In the library, the set cursor position moves to a row and column. There would be no difference between that and read. The only advantage I could see to a separate read position function would be to remember the old location of write and put it back. But that could just be done in the users code. With the read function, you just read out the address counter.

I think it makes the most sense to keep out bells and whistles (not because I am lazy) but because adding functions that the user will not use just makes the code bigger. I know there are ways to do conditional compiling, but I am not that advanced yet otherwise I would modify a nice FAT library to allow changing features since FAT libraries are around 10-13K in size when I mainly would only use read only!
416  Using Arduino / General Electronics / Re: How can One Turn 2.5V from Capacitor into 12V @ 1A DC Motor on: March 08, 2013, 09:53:19 am
Yep, caps in general are designed to store and release a charge quickly. The main difference in a supercap is that it charges quickly but discharges slowly and not capable of high currents due to internal resistance.

Things like motors, relays, solenoids require lots of current at startup, and relatively high currents throughout operation. So, a cap is well suited for help starting it up (hence why they are often used on motors) but not well suited for trying to power them long term.

You could experiment with PWM to prolong the use, but you have to start with a voltage higher than your motor requires. So, say 24V for your 12V motor. Then PWM max of 50% and you theoretically get twice the life out of a battery or whatever. A 12V or 24V solar panel will be fairly large though.

Your original question was how to turn the 2.5v from a supercap into 12V. You would use a voltage booster circuit (a special type of switching power supply) but it isn't that simple as you generally get less current capability out than you put in.
417  Using Arduino / General Electronics / Re: Stupid question: Part for distributing power/ground to multiple devices on: March 08, 2013, 09:23:08 am
Depending on what I am shooting for, one method I tend to use is to solder a paper clip (or resistor lead) across a board and simply wrap my distribution wires around it and solder them in place. I prefer that over trying to jumper across protoboard with solder (for some reason it never wants to do it when YOU want it to, but when you don't want it to... whole 'nother story!)

I also employ this method when jumpering pins on ICs, connectors, etc.. I use kapton tape also to isolate parts to prevent touching such as when I am jumpering pin 1 to pin 9 on an 18-pin part. I apply a thin strip of kapton tape to pins 2-8 right along the edge of the leads where they meet the IC body and then run my jumper along the top of the IC leads for a nice clean look. For bigger applications, I use liquid electric tape or laquer.
418  Using Arduino / General Electronics / Re: How can One Turn 2.5V from Capacitor into 12V @ 1A DC Motor on: March 08, 2013, 09:13:49 am
So what about simply trickle charging a battery with the solar instead? Unless the demand for the motor is very high, that may be an option.

And is a 12V/1A motor really necessary for your application? Is it speed or torque that you need from the motor?
419  Using Arduino / Project Guidance / Re: 350Mhz RF Remote. I know there is 315mhz and 433mhz. on: March 08, 2013, 05:30:21 am
The LED doesn't always blink. Do you have the module wired up already? If so, the library is meant to output to the serial port. So, you have to open the Serial Monitor in Arduino.
420  Using Arduino / Project Guidance / Re: Help making something safer. on: March 08, 2013, 05:27:57 am
Retroplayer,

Are you claiming that a burn ISN'T a shock hazard? It may not be fatal, but it's still a shock and a hazard. I'm sure your local 'Health and Safety' people would disagree with you.

Nope. I don't see a statement anything like that in my post. I said burns were more likely with DC, but that there was really nothing in this circuit to get to that level. If burns are really the concern, why not be concerned about the heat generated in those coils by running 5A through them? If anyone is going to get burned, that would be the most likely reason.

Good job reading!
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