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46  International / Hardware / Re: Como conectar un sensor digital de temperatura DS18B20 on: December 13, 2013, 05:58:31 pm
tienes el link the dealextreme? es para ver si esta el esquema.
sino, puedes mirar el datasheet. escribe en google datasheet ds18b20
hay dos formas de conectarlo, con 2 cables o con 3. te recomiendo con 3.
en google esta todo, pon arduino ds18b20 y tendras fotos y tutoriales
incluso en el Arduino IDE viene un ejemplo llamado OneWire/DS18x20_Temperature

intenta avanzar y sino pide ayuda pero pon lo que has hecho.
47  International / Español / Blink Led ! Como nunca lo habíais visto on: December 09, 2013, 11:53:57 am
Hola,

Para aquellos usuarios un pelin mas avanzados, si tenéis un rato (bastante largo) y con cierto nivel de ingles, os recomiendo leer este articulo. La verdad que le doy un 10 porque he aprendido muchísimo.

http://urbanhonking.com/ideasfordozens/2009/05/18/an_tour_of_the_arduino_interna/

Siempre había querido saber y entender que había detrás del código que escribimos en el Arduino IDE.
48  Community / Exhibition / Gallery / Re: Mini Wireless Router on a Shield on: November 30, 2013, 03:29:35 pm
Nice !
I also use several of this cheap routers, very easy to setup and no extra code on the arduino for wifi setup.

Did you attach an external antena? How? Does it improve signal?

nice pictures
49  International / Español / Re: valores negativos en las entradas analogicas on: November 24, 2013, 12:07:28 am
tienes que crear un offset de 2.5V y luego asegurarte que tu variación de voltaje sea de 2.5V maximo
aqui lo explica todo muy bien

http://openenergymonitor.org/emon/buildingblocks/ct-sensors-interface

50  International / Español / Re: AUTOMATIZACION DE CASAS AYUDA!!!! on: October 28, 2013, 12:02:09 pm
Hola Sergegsx.... gracias por la ayuda.... smiley

Siii tienes razon, entonses queda descartado la posibilidad de guardar en la micro sd, por ende quedan ya 2 opciones que me plateaste..... la de guardar en la eeproom o la de mysql......

Tu cual me sugieres?????

Depende de lo que quieras almacenar.
Yo tengo la casa con muchos sensores que me permiten ver muchisimos parametros, y el arduino que lo gobierna todo (MEGA) esta preparado en hardware y software para controlar luces, persianas etc. Incluso la web que cree esta tambien preparada, pero la verdad es que nunca llegue a implementarlo. Porque? pues porque no lo veo util. Me parece mucho mas interesante conocer los consumos de cada habitación, las temperaturas, control de la caldera de agua, grupo de presión, estado de puertas y ventanas, etc etc....antes de poder encender una luz con el movil. Al margen de esto, cuando yo lo programe todo lo hice de forma que las solicitudes de encender/apagar un equipo son enviadas desde la pagina web a una tabla mysql. El arduino cada vez que sube datos de monitorización a la tabla mysql, lee las solicitudes de acciones y las ejecuta si es necesario. Es una forma mucho mas lenta, pero te permite que no sea necesario acceder al arduino directamente. Te permite no tener que integrar la pagina web en el arduino. El arduino simplemente hace una consulta a la base de datos. Y en el servidor creas una web lo compleja que quieras y se comunica con la base de datos.

espero que te haya quedado claro, no digo que sea el mejor metodo pero para mis necesidades es lo mas apropiado que se hacer.
51  International / Español / Re: AUTOMATIZACION DE CASAS AYUDA!!!! on: October 27, 2013, 02:41:51 pm
Muchas gracias por tu ayuda josemanu.... smiley-lol

Pero el problema es....... que segun esto esa memoria tiene ciertos cilcos de vida no es asi????
Es mas facil acceder a esa memoria que a una micro sd????



depende que información guardes en la SD, si solo guardas esos datos pues no deberia ser muy complicado porque los datos estaran siempre localizados,. en cambio si vas guardando mas y mas datos tendras que saber buscarlos dentro del archivo de la SD.
Lo ideal seria guardar los datos en la eeprom justo antes de que se vaya la luz, para ello tendras que hacer un circuito con condensadores o pilas que detecte que se ha ido la luz y antes de que el arduino se apague, que guarde los datos. dudo que haya muchos apagones de luz, por lo que puedes usar la eeprom tranquilamente ya que aunque esta limitada en ciclos de escritura, tampoco va a irse la luz 100.000 veces.

si trabajar con la ethernet, y guardas los datos en una base de datos mysql por ejemplo. puedes consultar los datos al arrancar el arduino y restaurar la ultima configuracion
52  International / Español / Re: Medir consumo eléctrico. on: October 26, 2013, 11:18:28 am
lo habitual es que en este tipo de proyectos entre material y horas de trabajo no sea viable economicamente frente a uno comercial. pero el objetivo normalmente es aprender y crear algo que comercialmente no existe.
Si el sensor es lo que te sube el precio, te recomiendo estos

sct-013-000
sct-013-030

los tienes en ebay
53  International / Español / Re: Medir consumo eléctrico. on: October 26, 2013, 05:37:13 am
parece que no lleva resistencia de carga interna, tendras que añadirle una tu.
54  International / Español / Re: Medir consumo eléctrico. on: October 26, 2013, 05:36:02 am
Hola, alguien ha ensayado este?

http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Current/ECS1030-L72-SPEC.pdf

Al parecer es de 30a, es el que tengo en la tienda local...

Saludos...

Practicamente cualquier CT deberia de valer, solo tienes que asegurarte de varios puntos
- Si saca corriente o voltaje (no lleva resistencia de carga)
- Que la tensión a la entrada del arduino no supere 0 a 5 V. si vas a meter Vac al arduino entonces tienes que mirar que cuando conectas la mayor carga posible a medir (30A) no se superen los 2,5Vac
- Si el CT saca corriente, tienes que dimensionar una resistencia de carga para obtener voltaje
55  Using Arduino / Project Guidance / Re: Water Filter RO system controller on: October 22, 2013, 02:37:54 pm
Although all of the above are really good suggestions, let me add another one.
You could add one of this...

http://www.ebay.com/itm/10000mAh-USB-External-Battery-Backup-Power-Supply-Bank-Charger-for-Mobile-Phone-/360755678693?pt=US_Cell_Phone_PDA_Chargers&var=&hash=item53feb6cde5

You can plug the battery backup to the wall to keep it charging at all times, and then power the arduino with one of the 2 USB outputs. At least in the one ive got, this works perfectly, so if there is a power failure it will keep running from the battery for quite a long time. Then you would just need to make a way of knowing that a power failure has happened, which should be easy with a digital pin.

Very interesting your project.
56  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: October 19, 2013, 04:48:50 pm
Do not belive everything on the net.
CTR are important to calculate with. Look at the 4N27, 10% up to what I have seen as max, 600%.
The solution with the zeners are not optimal when the input signal varies 20 volts (60-80)
I have read earlier in this tread why the design was made like this.
Was it nessecery to let voltage in the span 0-50 volts be absolutly off.
With only a resistor, 0-10 volts can be off and over 60 on.

Pelle

Thanks for reading the thread to understand.
It was initially suggested to use zener diodes and it seemed a good idea, thats why i went that way. I also found it interesting to be able to make sure if the channel was really on or off, and by using the zener I would know for sure if the voltage is above 57V.
Apart from that, yes, the voltage can vary between 60V and 80V but I guess using the zenner diodes we are dropping the voltage enough to be save after that, right?

What is your suggestion? I am always open to learning new things, maybe there a much better way of doing all this.

dc42 I am still trying to figure out all the CTR things  smiley-roll-blue
57  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: October 19, 2013, 04:20:29 pm
1st part ---> Completely clear!  smiley-grin
I will leave the 1n4148

2nd part --->  smiley-eek-blue

This is my first project with optocouplers and all the tutorials on the internet are much simpler than all this. they dont go into CTR, they just talk about the optocoupler as a led diode, current limiting resistor and not much more.
58  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: October 19, 2013, 03:47:14 pm
Current for the 4N25

4N25 CTR  50 %

I dont understand very well your formulas, but:
if indicator LED current is choosen to be 10mA (maybe lower as i dont need it to be bright)

LED current  x CTR = phototransistor current.
LED current (10mA) x CTR 50% = possible phototransistor current 5 mA

If you use 10kohm pullup = 0,5 mA from optocoupler you only need 1 mA LED current.
I dont understand this last phrase.
as they are in series, if 10mA go through the status led, arent there going to be the same 10mA through the optocoupler led?
59  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: October 19, 2013, 03:29:25 pm
The full design is here, as you can see there are already 2 x 1n400x at the begining as protection. however, previously I was told to put also this  other diode across the optocoupler as it was a faster diode.  Is this correct? should I leave it or remove it?

Let me go through your calculations, CRT is new to me. After I read about it I will post again.
Thanks again pelle
60  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: October 19, 2013, 02:17:42 pm
Your revised schematics need amending. If you are going to connect the indicator LED in series with the opto isolator, then the 1N4148 diode should be in parallel with the series combination of the indicator and the opto isolator. Otherwise, if the 80V input is reversed, you will blow the LED.
Absolutely right, I forgot about that, Thanks for looking into it and telling me.
Attached the corrected schematic. (I left the SW2 switch to do some tests in the simulator)

Another issue with both the original and the revised circuit is that if you reverse the 80V input, then almost the full 80V appears across the 2.2k resistor, and it will dissipate about 3W. This is a consequence of adding the zener diodes and reducing the series resistor.
Anything that can be done with this? I understand what you are saying but I cant see this can be fixed, right?

You haven't told us what the forward voltage of your indicator LEDs is (or even what colour they are), so I can't calculate the exact current flowing through the circuit.
Sorry about that, its a regular 5mm green led. I dont know the forward voltage as I got them from the store without further information.  According to https://www.sparkfun.com/products/9592
Could we say "1.8-2.2VDC forward drop
Max current: 20mA
Suggested using current: 16-18mA
Luminous Intensity: 150-200mcd"

I really appreciate your help dc42, now and also in the past you have helped me.

btw. I dont need very bright leds on the PCB, just the minimum to see if the channel is ON or OFF. So the current through the LED+optocoupler can be lowered, 5mA is ok?
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