10 replies to this topic

[BigE]

Hi all,
I am new to the Netduino/hardware world but not to .NET so I am very excited about this product! I would like to buy one, but wanted to know more about how it works first. I have a very simple question regarding the design/purpose of the Netduino and I suppose the .NET Micro Framework in general:

Obviously the intended usage of a Netduino is to deploy your .NET app onto the device, letting it run standalone; however, can the Netduino be used as a "plug-and-play" device (similar to Phidgets) where a WinForms application can have direct control/access to it? My intent is to send digital outputs to control physical objects remotely. For example, write an app that can run on a server that I can access via my phone or another Internet-enabled device to control the Netduino connected to it.

If the Netduino is only designed for deploy-only, standalone usage, that's still a pretty cool device for $35! I'll probably be getting one regardless, but would just like to know more about how it can be used.

Thanks in advance!
-Eric

[Chris Walker]

Hi Eric, Welcome to the Netduino community! You can open a network connection between your computer and the Netduino (integrated on Netduino Plus, add-on for Netduino and Netduino Mini)...and use that for communication. You can also plug a serial cable from your computer into the Netduino Mini's RS232 pins or into an RS232 shield on the Netduino or Netduino Plus. Finally, we're working on adding bi-directional driverless USB communication into the Netduino/Netduino Plus firmware...but that's a ways out. Chris

[Fred]

If you haven't ordered one yet, I'd definitely recommend going for the Netduino Plus. It's only a few $ more than the standard Netduino and the included Ethernet will give you a lot more options for connectivity.

[BigE]

Awesome! So I could theoretically have an application running on the server handling incoming commands, and send responses over LAN via TCP/IP to the Netduino Plus? That would be great! I would definitely be intereseted in the Plus, but are there any left? I found the tech specs page but don't see anywhere to buy them... Also, I was unaware of the mini RS-232 ports (available in both models). Could I communicate to the Netduino/Netduino Plus via a serial port (or perhaps even a USB-to-RS232 converter cable, if the server doesn't have a serial port)? Thanks, and please forgive any hardware ignorance I might shown

[Chris Walker]

BigE, You can connect a 3.3V USB-TTL serial cable from a computer to the Netduino (using COM1 on D0/D1 or COM2 or D2/D3). Chris

[Philip]

Hi BigE If you are thinking 'remote' in a 'home automation' way, you could replace the serial link with an XBee (ZigBee standard) wireless link. The links cost about $50 for a pair, and behave just like a serial link straight out of the box (neither end need know there is a wireless link there). I'm currently playing with a system consisting of mobile phone (via WiFi) to PC containing webserver. The webserver executes server side scripts controlled by the mobile phone. The server scripts use serial to communicate wirelessly via XBee to a netduino board, which at the moment drives a mobile robot. The whole system works through walls up to about 20 ft. It looks like the mobile phone is controlling the robot directly (if I hide the server!). Digi International makes the XBee modules. Phil

[BigE]

Thanks for your responses. Phil: That is similar to what I am trying to do, but mine is far simpler! I want to interface with my mechanical padlock to unlock a door via my phone. In order to interface with the deadbolt, I need to be able to close the circuits to the right pins of the numeric keypad in the right order. Perhaps I don't even need a Netduino? This might be a dumb question, but can I simply use different pin combinations of a PC's RS-232 port (and some programming with .NET's System.IO.Ports) to close 6 independent circuits on command? (5 numeric keypad buttons, and a 6th "lock" button) Or would I need some hardware with more logic (i.e. the Netduino) and perhaps Chris' approach with the serial connectivity? -E

[entens]

Thanks for your responses.

Phil: That is similar to what I am trying to do, but mine is far simpler! I want to interface with my mechanical padlock to unlock a door via my phone. In order to interface with the deadbolt, I need to be able to close the circuits to the right pins of the numeric keypad in the right order.

Perhaps I don't even need a Netduino? This might be a dumb question, but can I simply use different pin combinations of a PC's RS-232 port (and some programming with .NET's System.IO.Ports) to close 6 independent circuits on command? (5 numeric keypad buttons, and a 6th "lock" button)

Or would I need some hardware with more logic (i.e. the Netduino) and perhaps Chris' approach with the serial connectivity?

-E

you can use just the serial port, but you will be limited to three outputs, plus it will be an epic pain in the butt to get working. i would recommend getting the Netduino to save yourself some gray hairs. If you still want to go down that rabbit hole, this article should get you started [http://slicksolution...dsdriver.shtml]

[Philip]

Perhaps I don't even need a Netduino? This might be a dumb question, but can I simply use different pin combinations of a PC's RS-232 port (and some programming with .NET's System.IO.Ports) to close 6 independent circuits on command? (5 numeric keypad buttons, and a 6th "lock" button)

Or would I need some hardware with more logic (i.e. the Netduino) and perhaps Chris' approach with the serial connectivity?

If you don't mind using wires to the lock, three independent outputs (from the COM port) plus a little logic circuitry could get you 8 possible outputs (enough, as you only need 6), but don't forget that the RS232 signals are around +/-10 V.

Phil

[BigE]

So it sounds possible but not very practical for someone who isn't overly savvy with logic circuits? Maybe I should just get the Netduino Plus? I still can't find where to purchase them. Are there none for sale?

[Chris Walker]

So it sounds possible but not very practical for someone who isn't overly savvy with logic circuits? Maybe I should just get the Netduino Plus? I still can't find where to purchase them. Are there none for sale?

Hi BigE,

The Netduino Plus officially goes on sale soon. The units that are out there today are from a special "public beta" batch we shipped back in September.

Chris