Show Posts
Pages: 1 ... 10 11 [12] 13 14 ... 184
166  Using Arduino / General Electronics / Re: Using a 4N35 for 10v - 36V sensing? on: July 11, 2014, 04:37:52 am
I had to use ac input to simulate voltage spikes..  you'll notice how the resistor divider works providing you don't go over your expected voltage, while the zener diode will happy take 120+v and you need not worry
167  Using Arduino / General Electronics / Re: Minimising power consumption on soil hygrometer sensor on: July 11, 2014, 04:33:05 am
The atmega processor can simply be lifted off the board, simply buy a replacement cpu and pop it back in...

(Gently prize it up both ends equally until it pops out, careful not to bend the legs)

If you don't, you will be powering a usb chip, 2 regulators and anything else hidden away.
168  Using Arduino / General Electronics / Re: Using a 4N35 for 10v - 36V sensing? on: July 11, 2014, 03:22:14 am
If you simply want to tap off the led current... all you need to is make sure arduino does not see > 5v

So a resistor divider will do it, no opto required, a 1k resistor and a 4v zener 5v may be on the boundry due to voltage spikes a 4v zener will ensure it does not go past 5v..

If you're really serious use a 5v TVS diode to clamp down the voltage from the resistor divider, slap in a cap to help give a nice dc 4-5v cleanish signal ..

169  Using Arduino / General Electronics / Re: Pro micro 5v - 3.3v CD4050 on: July 11, 2014, 03:13:24 am
Best going for an ldo (low drop out) 3.3v regulator or zener diode, not much in it really...

Is a switching reg going to be any more efficient?   No idea .
170  Using Arduino / General Electronics / Re: Reading voltage - Product already exists?? on: July 10, 2014, 11:29:49 pm
Yeah... We do need to know what voltage range you want to measure, and if it's AC or DC.

The code fungus gave you won't actually give you the voltage...  It will give you a number between 0 and 1023 that's proportional to 0-5V.   In other words, 5V will give you a full-scale ADC reading of 1023, and 2.5V will give you an ADC reading of 512.

To get voltage, multiply by 5/1023.

Code:
int v = analogRead(0) *5/1023 ;

That assumes you are reading a DC voltage less than 5V, and that you are using the default 5V internal reference.

Not strictly true, 5/1024...

And well analogRead does read voltage what else could it be? The battery's IQ?
171  Using Arduino / General Electronics / Re: Pro micro 5v - 3.3v CD4050 on: July 10, 2014, 11:26:12 pm
If there's no 3.3v   measure your 5v out digital pin, say it reads 4.7 try 2 or 3 diodes in series to drop the voltage.

I prefer a 3v regulator or a zener diode myself.... diodes are just a cheap way.
172  Using Arduino / Audio / Re: Pulsing a sound sample from Attiny85 on: July 10, 2014, 11:22:14 pm
Thank you so much for your help! I'm going to test out my breadboard this weekend and do some experiments with sound, so in the meantime, here's my modified code which contains the repeating pulsing PCM, with interrupts - please let me know if this looks okay:

Why not let yourself know if it works?
173  Using Arduino / General Electronics / Re: Minimising power consumption on soil hygrometer sensor on: July 10, 2014, 10:53:21 am
Once you have the final build, simply use the atmega chip on your own board, perfboard, stripboard etc so you're left just the sensor and cpu.

Get hold of a small solar panel to trickle charge the batteries, and you should not really need to worry about it for even longer.
174  Using Arduino / Sensors / Re: Analog reading whats not there on: July 10, 2014, 10:41:24 am
That's also normal...  you need to supply 5v exactly or there will be error...

So the easiest method is to change thd code from 5v / 1024 to what you actually have it might be 4.7v or 4.8v etc but when you use a multimeter to find out use that voltage instead of 5v
175  Using Arduino / Sensors / Re: Analog reading whats not there on: July 10, 2014, 09:57:21 am
Well the reason the voltage  is in flux is simply due to lack of pull down resistor (10k from a0 to gnd)

Your leds... need to see your circuit/code.
176  Using Arduino / General Electronics / Re: "a quasi resonant inverter" on: July 10, 2014, 09:35:21 am
I have ltspice and another high end circuit emulator which does everything...

Everycircuit is no where near complete granted... but (except the desktop) what makes this so good is the speed in which you can create the circuit and then test it, and I'm some what of a purist for example I'd rather use a transistor rather than use a NOT logic gate and this is why I prefer it.

Eye candy sure but what makes it great is the speed in which you can design and test it, the eye candy helps in understanding the flow current.
177  Community / Products and Services / Re: Anyone who knows about this Arduino clone... on: July 10, 2014, 01:52:29 am
The 2 header pins are labeled L and H ...

Are they simply 2 buttons you can use in your program..  giving a logic high or low?  Curious design..
178  Community / Products and Services / Re: Shameless ad for EveryCircuit. on: July 10, 2014, 01:35:07 am
The free version is lol....
179  Using Arduino / General Electronics / Re: "a quasi resonant inverter" on: July 09, 2014, 07:34:51 pm
The capacitor is incorrectly shown as polar.

There are no non polarized to select from in thus emu.
180  Using Arduino / General Electronics / Re: Question, wire as a variable resistor on: July 09, 2014, 11:19:28 am
Um...

What you did was a short circuit with tinned wire as there is little resistance, if there was electronics would be in trouble finding material good enough to conduct electrons.

Nichrome certainly, run a length of wire from the bottom of your room to the top, positive one end and gnd the other end, now take a 3rd wire (regular tinned wire)... insert tinned wire  into a0 on your arduino, now simply connect the tinned wire to any point of the nichrome wire, run it up and down and you'll see a value between 0 - 1024 or 0 to 5v

Depending on how many ohms per meter you may need a few inches or a few feet.
Pages: 1 ... 10 11 [12] 13 14 ... 184