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16  International / Español / Re: Se satura el puerto serie on: February 19, 2014, 02:42:30 pm
veo que usas strings, echale un vistazo a la libreria FreeMemory y haz que cada x minutos te muestre la memoria ram que te queda, a ver si puede ser por eso.
17  International / Español / Re: Cargador de coche para el Arduino on: February 16, 2014, 01:05:13 pm
Los que va a recibir dependeran del cargador que uses, ejemplo 0.5A, 1A o 2A
Los que requiera el arduino depende de lo que tengas conectado, arduino, lcd, gps, gprs, sensores, luces, etc
si vas a conectar cosas que vayan mas alla de componentes basicos, necesitaras coger los 5V que te da el cargador y alimentar estos equipos directamente de el.
18  International / Español / Re: Tipos de GPS compadtibles con arduino on: February 16, 2014, 01:03:01 pm
te recomiendo el ultimate gps version 3. compra tambien el cable adaptador de antena externa y la antena externa.
echa un vistazo a los ejemplos de github que usan en adafruit, funciona muy muy bien.
19  International / Español / Re: Cargador de coche para el Arduino on: February 15, 2014, 02:33:18 pm
pero como quieres alimentarlo? Por el jack o por la entrada USB?
Si usas la entrada USB le tienes que meter 5V.
Si usas el jack tienes que meter entre 7 y 12V.
Tambien puedes meterle 5V directos al pin "5V"
20  International / Español / Re: Cargador de coche para el Arduino on: February 15, 2014, 04:11:52 am
puedes usar un cargador de coche de tipo USB y conectar el arduino con el propio cable usb que usas para subir los sketchs.
21  Community / Gigs and Collaborations / Re: HELP HELP HELP HELP FOR MY PROJECT PLEASE!IF YOU HELP ME YOU ARE VERY SMART!!!!! on: February 11, 2014, 12:48:47 pm
I am not very smart but you need to post your schematics, and your code so far.
22  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 03, 2014, 05:34:17 am
Thanks Graynomad.

Its not, I just wrote 72 as an example. As I said, it can be anywhere around 70 to 80V, although normally is around 75V.

I am starting to think it might be a bit difficut to find an easy solution for requirement

Quote
6) At first I wanted to use zener diode to make a clear distinction between voltages under around 50Vdc and over it. The reason was that it should be around 75, so anything lower than 50Vdc does not make sense. However, I wouldnt mind if it can detect a range like under 50Vdc (logic 0) over 50Vdc (logic 1)

If its much more easier, I dont mind if the circuit will be activated as soon as there is any voltage on the positive. But as I say, it needs to be prepared to withstand 0 to 80Vdc.

Thank you very much all.
23  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 02, 2014, 11:31:32 pm
I think I'd probably use a comparator with high value resistors.

hi polymorph and thank you.
I will try to figure out what you mean cause I have no idea right now. Time for google. please let me know if you can develop a bit your answer.

thanks !
24  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 02, 2014, 11:28:39 pm
One more question: how many 75V inputs are there that you wish to monitor?

Initially I need 6 or 8.
Ideally for the future, I would like to have the possibility to expand to around 10 to 20.

Thanks dc42!
25  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 02, 2014, 02:06:50 pm
Hello dc42 !

Sorry about that.
Requirements.
1) Voltage can vary between 50 to 80Vdc (although it should be nominal at 75Vdc)
2) For each input, I need to put 1 led onboard, and 1 led in a case (that means there will be a 7 pin connector in the PCB to connect the external leds)
3) Voltage supply (75Vdc) has no power supply restrictions, (it can use far more than this board will need)
4) Reverse voltage requiered (in case its connected wrongly, or to prevent a certain channel feeding another one)
5) Negative for the 75Vdc will be common to all inputs
6) At first I wanted to use zener diode to make a clear distinction between voltages under around 50Vdc and over it. The reason was that it should be around 75, so anything lower than 50Vdc does not make sense. However, I wouldnt mind if it can detect a range like under 50Vdc (logic 0) over 50Vdc (logic 1)
7) Using SMD components (0805, 1206) so 250mW for the latest as max power dissipation I guess.
smiley-cool One of the two leds (the external mounted) will need to be hocked afterwards directly to ground. That way for 6 inputs I only need to extend a 7 wire cable (6 leds+1ground). If the led is between the circuit I would have to extend 2 wires for each input. Also that would make this external led necesary for the rest of the circuit to work which I dont want.

please let me know if more details are required, and thanks for looking into it.
screenshot Option1H is working correctly, but as I mentions has some problems when voltages go under 60Vdc, also the 10K resistors can not be replaced to allow more power to the led as they will get too hot.

Thanks again !

26  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 02, 2014, 12:38:44 pm
Option1H - Supply of 74V
Works ok. Problem that at 50V it will not work and that the Led D3 can not be very bright due to power dissipation in 10k resistors

Option1L - Supply of 50V
Does not work due to low voltage after zenner

Option2H - Supply of 74V
Works ok, but if voltage lowers then leds do not behave the same due to different resistors

Option2L - Supply of 50V
does not work, not enough current through resistor VR1, if I reduce VR1 value, then the Zener need to dissipate too much current.

I wanted to send this online to make the PCB and build my first SMD pcb, so power dissipation of components is crucial.
27  Using Arduino / General Electronics / Re: Arduino digital input, 80Vdc on: February 02, 2014, 12:28:28 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

Hello Pelle,
I am looking into this again after some real tests i have done and I am starting to understand you point on why this could be not a good way to go.

With voltages varying so much, I am having problems choosing the components. Either they use too much power, or the resistors do not suit to all cases.

Please could you suggest another method ? Anyone else?

I will post now some simulations which are very close to what I have been seeing in real tests.
thank you very much.
28  International / Español / Re: Voltaje variable con analogWrite on: February 02, 2014, 12:14:39 pm
echa un vistazo al enlace q tu mismo has puesto

http://arduino.cc/es/Reference/AnalogWrite
29  International / Español / Re: Voltaje variable con analogWrite on: February 01, 2014, 11:58:35 pm
pon el código completo
30  International / Español / Re: Problema con Arduino Mega y Ethernet Shield on: January 28, 2014, 12:30:56 pm
parece que tienes una tarjeta ethernet de las nuevas (yo no las he usado) pero por lo que veo los 2 pines que se quedan sueltos son las lineas de I2C (SDA y SCL) por lo que no son necesarias por el shield ethernet

fijate que el conector de 3x2 pines entre en su conector inferior, ahi esta la clave de la comunicación.

has probado el ejemplo webclient?
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