Currently I'm experimenting on a small scale using a window-box sized system. I'm in the process of building a greenhouse, and hope to automate it as much as possible, which is why I'm experimenting on the cheep now
For the full thing, I'll be building/buying sensors design for the long-term.

Thanks for the links! I actually have a pair or scrapped washing machines and a dishwasher, that I've been getting parts from as I need them. I'll see if I can find the sensor.

You might enjoy the video in this blog post: Plantduino Greenhouse Cares Of Your Plats While You’re Away In particular note how they use two ordinary nails to sense moisture in the ground.

All the details, parts list, schematic etc can be found at http://revoltlab.com/.

Danny,

Do you have a volt meter or multimeter?

If so, you should measure the voltage present on your motherboard's pins. Most serial interfaces use 12 volts which is too much for a Netduino. Please be careful.

thank you both for your replies. i, too, believe that i will really enjoy using this thing once i get over this first bump.

i have considered buying another device for interfacing, but i seem to be predisposed to doing things the hard way.

on my motherboard there is a 'COM1' rectangular 10 pin (minus one) socket. 5 pins on top, 4 on bottom. like this:

http://vip.asus.com/...SLanguage=en-us
http://www.frontx.com/cpx102_2b.html

i experimented today with pins D0 and D1 on the shield base connected to (what i think are) pins 2 and 3 of this socket. i got some lights and strange characters to come up on the program http://realterm.sourceforge.net/

but i do not know what the pinout is, nor which pins need to be connected, nor how to confirm the connectivity.


once all of that is done, i am confident i can trudge through the rest on my own.


your help is appreciated.


danny

Hi dannykyle,

First off, welcome to the Netduino community. Once you get over your initial frustrations I believe you will have lots of fun learning with your Netduino.

If you find that your computer does not have a serial port connector, don't dispair. Their are other options.

In particular there are USB to serial converters that plug into a USB port on your computer. One thing to be careful of though is the voltage. "standard" serial uses 12 volts which is too high for a Netduino.

This cable might work for you as it uses Netduino compatible voltages: https://www.adafruit.com/products/70

Alternatively this might be even better: FTDI friend There is even a full tutorial on how to use it.

The issue is that, if switching off the whole board, the Netduino wouldn't be able to wake up on time for the UI to flow nicely.

Have you measured the total time for your application to start from a cold boot? I am curious as I would have thought that it would be possible to get that into an "acceptable" range.

As for handling the keyboard and display, why not use a really low power chip (like perhaps the $4.30 TI MSP430 board) to handle that and cause the Netduino to boot as required (like when a key is pressed).

I just got around to fooling with this and it isn't clear (to me) how to interface this to the Netduino. The video mentions interfacing the the USB but there are no details. I suppose I can look at their SDK but I believe it is C++ and would require some port to Netduino.

Has anyone actually interfaced this to a Netduino?

The easiest way to interface the TI chip to the Netduino is via the TTL level serial port, both boards have them.

Hi Mikeo2721,

I wear out a USB port on my computers just about every year. They're rated for thousands of insertion cycles--but it's amazing how many times I unplug/plug things around here testing engineering samples, etc.

Anyway, let's make sure we get you up and running...

Chris

Chris, If you wear out a USB port on a motherboard that can be an expensive fix ;-)

Have you considered using a USB extension cable (male on one end, female on the other) and leaving it plugged into the PC continuously? That way it would be the extension cable that would wear out, not the socket on the PC.

The issue only has 2 votes on Codeplex! Go and Vote! (you might have to create an account)

http://netmf.codeplex.com/workitem/754

-Valkyrie-MT

I just made it 3.

A power sub-station with voltages measured in kilovolts and 1000s of Amps is really a special case where safety is paramount. As suggested in another response only properly designed industrial equipment tested and certified for such an environment should be used.

For others who might be considering measuring voltages in a residential location such as 120V or 240V (still lethal) there is a good "general" model to follow.

A Netduino (or any other micro-controller) is generally designed to operate on 5V or less (3.3V in the case of a Netduino). It is not designed to survive the application of high voltages (think of it this way, if it would kill you, it will kill a Netduino).

The best approach is to keep the high voltage (or current) on a separate board from the Netduino,

There are many Digital Multi-Meters (DMMs) out there which will output their readings on a serial port. The DMMs are designed and tested to be safe and reliable for measuring voltages and currents within their design specification. You can connect such a DMM to a Netduino via the serial interface (you may or may not need a level shifter such as a MAX232 but that is another issue).

Here is a post where someone used a DMM from Radio Shack in conjunction with a computer: http://www.linuxtoys.org/dvm/dvm.html The price they paid for the DMM seems high (old post perhaps?), I know I bought one on sale (different model) for about $30.

There is one general trend that needs to be remembered, Moore's law. With virtually any computer, the one being announced and shipping next year will be faster and a better value than the one you bought last year. Comparing the Rasberry Pi to the Netduino is like comparing a PC to a Mac, the latest Mac is better than the original PC and the latest PC is better than the original Mac. If we think of a Netduino in general terms, that is a single board computer that runs the .Net MF, then surely there will be a newer version of the Netduino in the future with more memory, speed, I/O etc. Just think how great a Netduino with a couple of Gig of memory would be. You could fit the full .Net runtime in that! For me there are two key takeaways from all these single board computers: 1) They are advancing at a rapid rate with lots of newer, cheaper, more powerful ones coming out all the time. 2) These things are so cheap that it is easy to buy several to experiment and learn, there is no one perfect solution for everything. What a great time to be alive!

Tell us more about your sailboat,what kind, how big, do you liveon it etc.?

I have a LeComte NorthEast 38 sloop.

Many boats have expensive batteries,and monitoring them properly can make them last much longer and save a ton of money. Properly maintained (as in a data center) deep cycle batteries can last 10 years. Many boaters consider themselves lucky to get 3-4 years before replacing them.

If you want to do a really good job of battery monitoring consider using Kelvin 4-wire leads (http://en.wikipedia....erminal_sensing )

For an audio device you most likely want a logarithmic rather than a liner taper. In looking through the data sheet (quickly), figure 2-2 (page 17) seems to show this as a linear taper.

OK, more digging... I found two good candidates, one 129-steps and one 256-steps digital potentiometer at 10kohm for good money.

I think these will work fine. Now how do I control a bunch (5-8) of these with Netduino, can I do that?

http://se.farnell.co...ip14/dp/9758615
http://se.farnell.co...-spi/dp/1578436


/Ken

Take a look at http://videos.analog...elopment-Board/

You can get one for $30 here: http://www.analog.co...ts/product.html

This board runs on 2 AA batteries and logs the data to an SD card. After your workout session you could put the SD card into your Netduino Plus and do whatever with the data.

Very nice tutorial, it got a tweet from me ;-)

If you would like to see the .Net MF runnng on a M3 take a look at:

http://blogs.msdn.co...ce-project.aspx

I have been looking at Go module development and can see that another tool in people's toolset is a logic analyser would you say that this is he case?

With this in mind I was thinking of getting the sparkfun bus pirate as it's quite cheap. Would you say that this is a worthwhile purchase?

http://www.amazon.co...=A2UJ1UULX429TJ

Cheers,

Mike

Have you checked out http://dangerousprot...-pirate-manual/ ?

Keven is correct that a logic analyzer is a great tool, and will do more. That being said, the stuff from dangerous prototypes can't be beat for the money. $30 for the bus pirate is very cheap; of course you will probably want to buy some cables etc which will bring the price up some.

You may also like their logic sniffer - http://www.seeedstud...2.html?cPath=75 At $50 it too is very attractively priced.

Another option is to get a good used analog oscilloscope, I picked up a used Tektronix 100 Mz dual channel unit that is absolutely top quality. If you shop around you should be able to find one for $100 or less, often much less. Look on Craigs List and E-Bay. It is best if you find one locally as they are big, heavy and easily damaged in transit if not packed properly for shipping. Plus if you buy locally you can verify that it works before handing over your cash. I have heard of many people who were poor students without much money who have asked around and gotten used scopes for free, although that route will probably take you longer. Good luck!

The code is far from 'perfect' but seems to work OK. There is one known issue. On rare occasions, the message string sent to the Netduino for setting the PWM has missing data. The Netduino will return a message informing you of the problem. To be blunt, I have no idea why, but at least it does not happen very often. I live near the BIG Chicago airport and I have issues with electronic items in the home at times. I 'think' it is from aircraft transmissions of some sort. Anyway, a plane is usually flying over and then have strange thing happen around here. Like hear voices on the TV and FM radio.

The usual way to handle situations like this, (namely sending data over noisy communications channels where the message can be garbled) is to include a checksum ( http://en.wikipedia.org/wiki/Checksum) with the message.

Basicly the sender computes the checksum and includes it with the message. The receiver then gets the message and re-computes the checksum to confirm that the computed value matches the checkum received. If they do not then the receiver knows the message has been corrupted and treats it accordingly. (One standard practice is to simply ask the sender to re-send the message).

This may or may not be overkill for your purposes.

Hello Avax,

Welcome to the Netduino forums.

In the past there has been some discussion of CANbus, but I don't know what the current state of that interface is for Netduino.

I do know there are several people (including myself) who would like to see it on the Netduino.

Hopefully others may provide more detailed information.

Hi everyone,

I am a total newbie here.

I have a project I am working on involving LIDAR. The laser measurement device supports CAN bus and I would like to communicate with it using CAN.

I like the netduino platform because I am an experienced .net developer and would like to stay in visual studio if possible.

Anyway I did a search here on "CAN" and nothing came up, but it very likely could be a filtered word like "the".

If anyone has any information on an existing project or thoughts on what hardware would be required to communicate on a CAN bus it would be appreciated.

Regards
Avax

In another thread Chris stated: The modules should be flashable via go!bus, no special hardware required. And with the upcoming standard virtual I/O firmware, you'll be able to just say "use pins X, Y, and Z on the STM8S for the following features" and no knowledge of C or STM8S architecture will be required. Those pins/features will simply become "part" of the mainboard. WHat is the current status of this? I would like to flash a potentiometer module.

Status update: the basic flashing routine for STM8S modules is working, at this moment in byte mode (*). Now, when the reflashing app for STM32 is available, it can be extended to include flashing of STM8S-based modules, so we can have an unified interface.

(*) Byte mode is the slowest, word and block programming are faster, but a little bit more complex.

Would you be willing to give a status update as well as information on how to get a copy of the flashing routine?

Thanks.

Hello Mozsi and welcome to the wonderful world on Netduino!

I am not a Mac person, but I can tell you that having simple routines that allow reliable communication between a microcomputer and a desktop (e.g PC or Mac) is something that virtually everyone struggles with. The key hangup is reliability.

To be useful in the real world communication needs to be resilient; automatically recovering from such things as power failures, cables being unplugged and being plugged in again etc. If that is something you can workout it will be a great service to us all.

I don't know if this helps, but here is a project someone is doing for the Arduino: http://robotgrrl.com...no/matatino.php

The design surface in Visual Studio for .Net Gadgeteer is very cool, particularly for documenting how the modules are connected. The code generation is of less interest to me for Netduino GO.

Here is a blog post showing how it works.

Has anyone given any thought to having this for Netduino GO?

Hi,

i want to use my netduino code on an trinamic eval board. it has a AT91SAM7X256 instead of AT91SAM7X512

I believe your biggest problem would be that the AT91SAM7X256 has 256 Kbytes of flash wile the Netduino has 512K. I wouldn't say absolutely that it is impossible to get the .NET MF into 256K, but it would be a major challenge.

Far better to select a chip with adequate memory.

I ordered and received one. As a watch goes, it is extremely thick and heavy. It definitely scores major geek points though :-)

I just ran across this excellent, simple guide to connecting external parts to a microcontroller: http://cq.cx/interface.pl#10

It is not Netduino specific, but would work with any microcontroller.

One caution, in his examples he often shows the voltage level as 5 volts, which would be fine for an Arduino or many other microtrollers. The Netduino is a Netduino is a 3.3 volt device so just replace 5 V with 3.3V in his drawings.

He describe how to:

Light an LED from a Digital Output
Read Switch Contacts with a Digital Input
Read a Digital Signal that Goes from 0 V (LOW) to 10 V (HIGH)
Read (with Opto-Isolation) A Digital Signal
Measure a DC Voltage Between 0 V and 15 V
Measure a DC Voltage Between -15 V and 15 V
Measure a DC Voltage Between 0 V and 1.7 V
Measure the Position of a Potentiometer
Measure an Unknown Resistance
Measure a Temperature
Output Characters on an LCD
Switch a 100 mA, 10 V Load
Switch a 1 A, 10 V Load That Always Stays Connected to Ground
Switch a 10 A, 40 V Load
Switch a 120 VAC Load