23 replies to this topic

[Miha]

Hi guys! Disclaimer: I am total newbie regarding *duino stuff and a newbie with regards to electronics as well. I am, however a software developer. That said, I have an idea for a project and would love to hear your input and advice on this matter. Problem: we have a (weekend) located in the hills and I would like to remotely: * turn on the heating (oil pumps, water pumps, oil furnace) * adjust the temperature on the thermostat * retrieve a reading of some parameters (inside temperature in the beginning) I found out about the netduino platform which seems really approachable to me, so if you can help me out with some ideas, suggestions and pointers, I will be grateful. Now, about solving the problem. I have 5 copper wires running from the living room to the basement, where the furnace is located. I figured I could use 3 wires for Ground, L and N (220 V), and two remaining wires for controlling the rele (or contactor) for turning on the whole shebang (furnace, pumps) and another wire for regulating the pumps (in the same way the current simple thermostat does now). I would replace the current thermostat with a SuperSmartNeduinoThermostat, consisting of: * Netduino plus * GSM module * LCD module * a few buttons * Thermal sensor I don't really know where to start (I guess by ordering?) so I've come up with something like this: * A breadbord and some wires * Buttons for controlling the temperature and setting up (http://www.sparkfun.com/products/7836) * LCD: http://www.sparkfun.com/products/709 * GSM: http://www.sparkfun.com/products/9607 with an appropriate antenna * Thermal sensor: http://www.sparkfun.com/products/10167 or something similar * NiMH/LiIon/LiPO battery for backup power Questions: 1) LCD: Do I really need 11 pins just for the LCD? 2) What about power supply? I will have 220V. I would need a small switcher probably? (hints appreciated) I was also thinking of providing backup power through battery. So that when power outage happens, the netduino would still operate. How do I achieve automatic switchover or maybe better yet, powering it through the battery all the time where battery would act as a buffer? 3) Saving data: I guess this can be accomplished with the SD card with Netduino plus? At first, I'd only like to store configuration data (chosem temp, last reading, authorized numbers) 4) When I'm done prototyping, what next? How do I make a finished product? (just 1 piece) Do I have to make a PCB? If so, I'll have to find a good soul in the neighbourhood to help me do it. 5) What about long distance temp sensor? How could I have a wired sensor apx. 8m from the board? 6) I'm from EU. I've looked at European distributors, but they are either out of stock or don't carry particular component. Are there any recommendantions as to where to get this stuff? I would prefer to get it from one distributor as opposed to many of them. For starters, that would be all. Eagerly awaiting your responses. Kind regards, Miha.

[CW2]

So, what you want is basically a GSM controlled power outlet (aka GSM relay) for the heating, and GSM controlled thermostat?

[CW2]

Problem: we have a (weekend) located in the hills and I would like to remotely:

I assume there is a missing 'house' or 'cottage' in the sentence above, but my question: does the electricity stay turned on? I am asking because we always switch everything off (main breaker) when leaving our cottage, for safety reasons.

[Charles]

Not to discourage you from this course, and it would make a great project, but heaters can be finicky things and the risk to your property if it should malfunction could be great. Before you set out on this endeavor, have a look at this... It works over my Internet connection and has many compatable mobile phone clients: http://www.proliphix...stats-nt20e.htm It works great for me and I have no complaints.

[Chris Walker]

Hi Miha, Sounds like a cool project. Very doable. Have you thought of using a Netduino Mini and a Wiznet module for a "final solution"? There's also nothing wrong with just using a Netduino Plus. The one thing to watch out for is to make sure that anything you're interfacing with has safety systems built in. Chris

[bill.french]

I like this project. Tell me if I'm understanding correctly, based on what you said and my imagination: A. The Goals: 1. While away from the cottage, run the heat at very minimal levels to prevent pipes from freezing 2. Turn on the heat to warm the cottage up before you arrive 3. Monitor and report problems remotely B. The Risks: 1. The heat never comes on and the pipes freeze 2. The heat never shuts off and you get a big heating bill, wreck the furnace, or burn the place down In the US, every "heating only" thermostat I've ever seen only have two wires, that when connected (via a relay or other mechanical connection to complete a circuit) tells the furnace to operate. The furnace itself has some sort of electronics to fire itself up, turn on pumps on and off at the right times, etc. Maybe the netduino's role could be limited to reporting back temperatures, and allowing you to remotely switch between two thermostats via a relay? One thermostat could be a cheap programmable one set to normal temperatures, and the other a very basic unit that is set to somewhere above freezing to keep the pipes intact. This way, if the netduino (or, much more likely, your code fails) the fallback mode is just a regular thermostat.

[darkSol]

Not sure if this helps but...

I have a home server downstairs with a USB->RS485 adapter talking to two of these (basement/main & upstairs HVAC): http://www.datanab.c...rollers/iT8.htm

Dirt simple protocol to talk to and pretty cheap.

I'm thinking about offloading the C# code that's running off the webserver to the NetDuino Plus... maybe

[Miha]

Thanks for the feedback. Some answers (and more questions ): @CW2: Yes, that is it. And yes, there is a word missing. We don't switch off the main power supply, we just close the main water valve and, depending on the outside temperature leave the furnace on or off. If outside temperature is above 0 C, we turn the furnace off. If outside temperature is below (or projected temperature for the next week) 0 C, we set the thermostat to 5-7C and turn the furnace on. @Chris: I don't know. As I have no experience whatsoever with this type of project, I'm kind of lost. So do you think I could prototype everything with Netduino Plus + GSM module and then make the final product with Netduino mini and Wiznet? I suppose I will need to build a PCB at some point, right? What about storage (config data)? What is the relation between cellular shield and wiznet module? Is there some alternative to cellular shield to achieve SMS functionality? What do you mean by "... with has safety systems built in"? @bill.french: yes, pretty much. The goal is also to change the thermostat value remotely. That's the reason I was thinking of replacing the thermostat with Netduino altogether. The furnace and thermostat work in this way: * furnace (furnace, oil pump, oil ) is connected to mains power supply (I think the US term for that kind of furnace is oil boiler). The furnace has its own thermostat defining the working temperature of the furnace (set to ~60-80 C). The then heats the water, which is pumped around (two circuits: one for heating rooms via radiators, another for heating drinking (sanitary) water). There is a (motorized) mixing valve, which is what room thermostat controls. When thermostat is "ON", the hot water flows through radiators. When room thermostat is "OFF", the hot water just flows internally through the furnace and drinking water boiler. The thermostat works like a switch for the mixing valve (turning it one way or another). The netduino would be connected in the same way (I would use one wire to control a rele to simulate the behavior of a thermostat). @All: do you think I've got the right components on my list, or should I change something? I would love to hear some buying advice for an EU customer. Kind regards, Miha.

[Charles]

I cam across this Arduino project a while back and thought it may provide some insight:

Arduino Thermostat

[Miha]

I cam across this Arduino project a while back and thought it may provide some insight:

Arduino Thermostat

Perfect! I'm also testing a UMTS wireless router as we speak, so maybe I can skip the cellular module on a netduino and use internet (ethernet or wifi) for connectivity.

[Miha]

Hey guys!

I'm very eager to order all of this stuff. What I'd like to know before I order is:

• LCD: maybe this? http://www.sparkfun.com/products/10168
• battery backup: any pointers for how to handle cases of power outages? I mainly want to store config data. Is SD card necessary for that or does Netduino have some sort of (small) storage available?
• What kind of thermal sensor do you recommend?

And, most importantly (are you all from US?? :)), recommended online shops where I can order this stuff.

Sincerely,
Miha.

ps: are there companies that would create and send me a PCB (one or two pcs) via mail based on my drawings? (for the final product)? I guess sticking a breadboard with wires into a 'housing' is _not_ the way to go :)).

[bill.french]

1. The LCD you listed, two members are working on it and have it functioning, minimally (i just ordered mine this week)
2. Config storage: this is a little mysterious right now
3. Thermal sensor: I like the DS18B20 but then you'll need a onewire controller - and then you can read 6 sensors easily, here's a thread about it
4. You can always etch your own PCB -- it's pretty easy

[Miha]

3. Thermal sensor: I like the DS18B20 but then you'll need a onewire controller - and then you can read 6 sensors easily, here's a thread about it

Can you please elaborate on the 1 wire controller? Is this something I need to build or can I buy it? Maybe from SK Pang? (I'm ordering the stuff from there as I write this). The one-wire controller mentioned in that post looks intimidating to me. Is this something I buy and connect and, presto, it works, or...?

[Miha]

I ordered some parts, so hopefully, I can start working on this in a week or so. Then, questions will follow.

[bill.french]

The one wire controller acts like a bridge connecting onewire stuff to serial. It's pretty straight-forward, a couple folks (including myself) here have gotten it working. You can get it from here: http://www.phanderso...mp/onewire.html

[Miha]

The one wire controller acts like a bridge connecting onewire stuff to serial. It's pretty straight-forward, a couple folks (including myself) here have gotten it working. You can get it from here: http://www.phanderso...mp/onewire.html

I see. But he wants to charge 200 USD !?!?!? to ship to Europe. I guess there must be something wrong with his paypal setup. Is there another way I could use the DS temperature sensor I ordered?

[Jan Olof]

Miha, Member CW2 is working on OneWire drivers for the Netduino. At the moment that needs special firmware, but it will bee integrated into the official release when ready. There is a prerelease in the forum somewhere (you have to search), if I remember correctly there is 2 versions the original and a updated. This firmware may not contain all the other updates that is in the Alfa releases you can find in the forum. /Jan Olof

[CW2]

Member CW2 is working on OneWire drivers for the Netduino.

At the moment that needs special firmware, but it will bee integrated into the official release when ready. There is a prerelease in the forum somewhere (you have to search), if I remember correctly there is 2 versions the original and a updated.

The custom firmware is available for download and experiments through the following links:

• CW.NETMF.OneWire-1.0.5.0.zip (source code only, for details see this post),
• OneWire ALPHA (obsolete)

I am waiting for SecretLabs to publish the complete firmware source code, so I can release custom firmware that contains all features (if there is interest). Currently, the PWM functionality is still in pre-release phase, it is not included in the official source.

[VincentA]

I see. But he wants to charge 200 USD !?!?!? to ship to Europe. I guess there must be something wrong with his paypal setup. Is there another way I could use the DS temperature sensor I ordered?

I just checked out!! its funny, Product costs ~$8 and shipping costs $200... who would buy it outside US ?

[Miha]

The custom firmware is available for download and experiments through the following links:

• CW.NETMF.OneWire-1.0.5.0.zip (source code only, for details see this post),
• OneWire ALPHA (obsolete)

I am waiting for SecretLabs to publish the complete firmware source code, so I can release custom firmware that contains all features (if there is interest). Currently, the PWM functionality is still in pre-release phase, it is not included in the official source.

Excellent news! I'll test it as soon as my stuff arrives. It was dispatched today... can't wait to get my hands on it. :) (like a kid waiting for a new toy :))

Best,
Miha.