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46  Using Arduino / Motors, Mechanics, and Power / Re: Temperature-controlled Freezer on: August 16, 2012, 10:20:25 am
Of course smiley. The original thermostat does not allow precise temperature control (i.e.: 4°C), it only has vague "levels of cold" (i.e.: 1 ... 5). Since I need to maintain some precise temperature, I have to resort to a different solution.

As mentioned, I've already done it with an off-the-shelf temperature controller, but now I want to be able to monitor (and control, to a certain degree, i.e.: bypass) the situation remotely, so I need to build my own web-enabled temperature controller.

Thanks for the hint!
47  International / Hardware / Re: Connettori Dupont on: August 16, 2012, 07:16:07 am
 smiley-eek smiley-eek smiley-eek smiley-eek smiley-eek

Grazie delle info, comunque!
48  International / Hardware / Re: Connettori Dupont on: August 16, 2012, 04:56:41 am
Grazie! La spedizione da Macau è affidabile? La Dogana è tanto "severa"?

Per la pinza, sapresti almeno passarmi una foto o un link tanto per sapere almeno cosa cercare? smiley
49  International / Hardware / Connettori Dupont on: August 16, 2012, 04:01:11 am
Ciao a tutti,

vorrei potermi fare da solo i classici "jumper cables" da breadboard, in modo da poterli fare della lunghezza giusta e con maschi/femmine all'occorrenza.

Mi pare di aver capito che i connettori che vengono solitamente utilizzati si chiamano "Dupont", ma non riesco a trovarli facilmente. Per caso conoscete qualche sito che venda sia i maschi che le femmine che le "coperture" in plastica? Un kit con un misto di tutti e 3 non sarebbe male smiley.

Oltre a questo, dove trovo (e soprattutto: qual è!?) la pinza per crimparli? So che si può fare manualmente con delle pinzette, ma preferirei un modo più rapido per farlo.

50  Using Arduino / Motors, Mechanics, and Power / Temperature-controlled Freezer on: August 16, 2012, 02:25:09 am
I am planning of using an Arduino to control the internal temperature of a freezer.

Since I don't want to modify the freezer, I will take the approach of switching its mains supply ON/OFF through a SSR. This has already worked well enough with an off-the-shelf temperature controller, so I am not expecting major problems.

Two questions, though:

1. Will I need a snubber circuit to protect the SSR? I don't think so, since I will not be driving the compressor directly, but I'm far from being an expert in electronics, so I'm not sure.

2. I was originally planning of writing the controlling algorithm myself, but then I found out about the PID library: would you recommend its use?

51  Using Arduino / Networking, Protocols, and Devices / Re: Get internet service provider or provider's IP adress? on: August 13, 2012, 03:43:19 am
Not sure I understand the question, but maybe this can help:
52  Using Arduino / Networking, Protocols, and Devices / Re: Switch Slave Select pin with Ethernet shield on: August 13, 2012, 01:56:05 am
Another alternative could be using a shield based on the ENC28J60 chip. You will have to use EtherCard instead of the official Ethernet library, which has quite a different interface, but it will allow you to pass the SS pin to the begin() method.
53  Using Arduino / Networking, Protocols, and Devices / Re: Switch Slave Select pin with Ethernet shield on: August 12, 2012, 04:34:59 pm
Right today I have been testing a way to connect ad Ethernet Shield to an Arduino clone that has a different form factor (Luigino 1000pads, BTW). This involved doing something like you did (i.e. connect the shield through wires) so I took the opportunity to test what you ask: I changed 5100.h like you did, then compiled the webserver example, which successfully worked. My connections are the following:

Using female headers:
L (Luigino) D8 -> ES (Ethernet Shield) D10
L +5V -> ES 5V

Luigino female headers to ES ICSP/SPI connector:
L11 -> 4
L12 -> 1
L13 -> 3
(This is wrt the SPI pinout as described at

Note that my ES is not the official one, but rather a clone, so YMMV. Maybe you might try connecting the SS signal to pin 5 of the SPI header.

Hope it helps!
54  Using Arduino / Networking, Protocols, and Devices / Re: Enc28J60 socket API on: August 10, 2012, 07:41:23 am
Any idea which of EtherShield or EtherCard would be a better start ? Anybody wanting to collaborate on that ? The first step wouldn't include any programming, only collaborate to understand the differences... And why not, put the result somewhere in the playground.

Why not turicas's? He seems to have already done most of the job. I haven't tried his work yet, though. Maybe I'll find some time to do it in the weekend. Oh, and I've found another one: Quite rough and I can't get it to work, but has some good points:

- write function can assembly one big packet from smaller chunks

- buffer (1536bytes) for TCP/UDP data directly on enc28j60 chip. Thanks to this we can use "available" and "flush".

I think compatibility with Arduino Ethernet library is now within your reach Wink

BTW, I am currently using EtherCard on KmTronic's DINo with good results, anyway. @4ntoine: Are you sure your code is OK? With a 700-800 byte packet buffer it's quite easy to run out of RAM smiley-sad.
55  Using Arduino / Sensors / Re: KMtronic DINo's opto-isolated inputs on: August 08, 2012, 04:17:08 am
Yeah, thanks, I was writing the following post just before you (tochinet) posted your reply:

I've found something at:,58324.0.html, in particular:

Can you tell me if it is possible to isolate the data line from the sensor to the boards input pin with an optocoupler ?  

That won't work in any simple scenario...

Both the Arduino and the DS1820 "hanging" on the data line need to be able to pull the data line low. The pin switches between being an input and being an output.

So it seems I can't connect the DS18B20 to IN1/2/3/4, since the connection needs to be bidirectional and the opto-isolator of course make it monodirectional.

I was thinking about moving the Dallas microlan away from P1 since I am planning to add an LCD to my system using the 3-wire protocol, and I meant to use A0, A1 and D2. I guess I will have to either get rid of the serial port, so that I can use D0 and D1, or use a 2-wire LCD protocol.
56  Using Arduino / Sensors / KMtronic DINo's opto-isolated inputs on: August 07, 2012, 01:24:02 pm
I have bought an Arduino DINo from KMtronic:

So far, everything is working great. I can control the relays and use the network through EtherCard, and will soon provide the community with the result of my work smiley-mr-green.

Now I would like to connect a DS18B20 temperature sensor to my board. It works OK if I use pins from the P1 connector (3.3V, GND and D2), but I can't get it to work using the opto-isolated inputs. I don't even know how to wire it properly. I suppose 3.3V and GND would still go to P1, and the data line I would connect to P2 would go to the "+" terminal of IN1 (for instance), but what should I connect to the "-" terminal? I tried connecting it to GND but it didn't work.

Can you help me?
Thanks in advance!

57  Using Arduino / Programming Questions / Re: Static initialization of PGM_P in struct on: July 30, 2012, 02:34:08 am
OK, it seems there is no other way smiley-sad. Thanks WizenedEE.
58  Using Arduino / Programming Questions / Static initialization of PGM_P in struct on: July 29, 2012, 02:50:50 pm
Suppose I have a struct like:

struct SomeStruct {
PGM_P name;
// Other fields...

I would like to write:

SomeStruct s[] = {
{PSTR ("One")},
{PSTR ("Two")}

Unfortunately the compiler refuses to compile this. I can work it around with something like:

const char oneStr[] PROGMEM = "One";

SomeStruct s[] = {
// ...

But it's a bit too complicated for my taste. Is there a way to put the strings inside the array declaration?

Thanks in advance!
59  Using Arduino / Project Guidance / Re: "Smart" Power Strip on: June 29, 2012, 10:49:51 am
OK, thanks!
60  Using Arduino / Project Guidance / Re: "Smart" Power Strip on: June 29, 2012, 10:21:57 am
No idea, I haven't even installed the IDE, yet. I'm still at the design phase.

Anyway, I'd use the one library you'd recommend, I guess! smiley-grin
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