Yes you need it when you don't know C or C++ and only know Visual Studio as a compiler lol I come from VB6 ... therefore, netmf is my best bet ! And I don't want a professional quality flight control, I just want mine By the way, my main goal is to learn .net and I decided to start with .netmf ! This community rocks ! Mike. p.s.: You should see my smile lol

I know lol and that is why i have a 200MHz .Net MF waiting for me to get up to speed with coding sensors to try it out I'm a slow learner ... not as agile as I used to be lol mentally that is !

Any left ? Mike.

Any updates ?

Still new at all this but thinking of buying a couple of sensors to play with to understand what is at stake ... I liked the idea of having a 9dof sensor I'll add a GPS, Temperature and Barometer. Any good altimeter around ? And a few proximity sensors (for autonomous flying) ... Still need paypal prepayment of 40$ ? PM me ! Mike.

We are going to make our initial board run of 9 boards.

Do you need something more from me

my problem is trying to get it to microsecond accuracy

Sorry, I missread it ...

Welcome to the community Yes try this Thread.Sleep(500); for 500ms or Thread.Sleep(Timeout.Infinite); for a tad longer And the main problem is with the garbage collector that kicks in ... I don't remember how long it can take in some instance.

.NET MF 4.2 (beta coming by summer) includes a new "simple storage" mechanism for storing data on-chip. We'll be embracing this in the Netduino 4.2 firmware to enable you to read/write data from your Netduino app as well.

Just to see that I understand : lets say you have a normal netduino with XBee but no SD card, you could send info to the netduino that would persist even after power recycling (like encryption key or remote ip address of neighbor sensor or ...) ? That could be interesting

Yes, you'll have 4KB or more of storage space to store data. It only has 10,000 rewrite cycles for flash rewrites...so you won't want to rewrite it frequently...but it'll be awesome for configuration data.

Quite ! specially for very small remote sensors using the mini ! Configuration yes, daily values ... not really since 10,000 cycles (about 27 years if one per day)

And of course, Netduino Plus has MicroSD support...so you can store data there easily too.

Was thinking of the mini or normal ones

Just leaving a breadcrum to remember Thanks Omar !

It would be nice if there was a beginners tutorial on using I2C with the Netduino. Not just the code but connecting multiple devices to the bus. I know your suppose to use pull up resistors but I can't find any information on when to use them what type or how often. But a short and sweet tutorial would be great to answer these type of question us beginners have. And it would have the added benefit of being easily found.

I agree ! Beginners Tutorial Please

Sorry for the confusion.

LOL It made my point clear though ! LOL

Did I understand correctly, you ALWAYS need pullup resistors ? or only when there is more than one sensor connected to it ? And using a I2CBus class to encapsulate all this would be nice to have (to clean up the code) ?

There need to be two pull-up resistors connected between I2C signal lines (TWCK, TWD) and positive voltage (+5V or +3.3V depending on the devices connected). The value can vary from ~1.5 kΩ up to ~47 kΩ, 2.2 kΩ or 10 kΩ will work fine. The exact value would have to be calculated based on the bus characteristics, i.e. capacitance, number of devices connected, speed etc.

And if I see only SCL and SDA ... no TWCK nor TWD ... This is why we need a tutorial ... with some diagram using a netduino and some sensors (ex: Accelerometer ADXL345, Magnetometer HMC5843 and Gyroscope ITG3200). Real example with real sensors ...

I do understand that hardware is hard (pun intended) ... please help the newbies like me with some tutorials with real things connected, not just LEDs I am willing to help but I need input ... hard input !

Mike who wants to play with sensors without burning them !

However, some sensors/devices may have those built-in (e.g. Sparkfun breakout boards).

Boy do we need a tutorial LOL

what do you mean by 'encapsulate all this'?

Sorry, my lack of knowledge ... I didn't know why it was created ! Thanks !

I don't know if you want to use this, but as your project grows, you might find it easier. Good luck!

How do we discriminate the request received ? Where is the command string ? Where are the arguments ... needed ...

I find the other one easier to use ... you declare actions, you switch between the ones you defined ... How do you know which command to call ? Or I missed the whole point

For instance, if you would program your Netduino to be a thermostat, you would call

http://192.168.1.100/settemp/livingroom/21

to set the temperature in the living room to 21 degrees.

Imagine a series of netduino mini (as thermostat) using XBee to communicate with a router, then imagine a base station (or multiple with touch screens) that can send command to all the other "sensors" through the router ... you could have all the thermostats in the house connected to a router and a series of control panels also connected to the router and have the computer send preprogrammed sequence to all ... you could even change settings from the office using the internet

Very good work Jasper ! Thanks !

I was asking about how do you discriminate which action to take in your main function on the netduino ... I know that the worker has the code to do the actions ... but how do we test which command was asked to the webserver ? If you only send one command, why do all that structure lol

the only problem that I am having is that the readings bounce all over the place. From 85-65F after i calculate it or 210-230 ADC value its reading.

I found that it takes about 10 seconds for the values to stabilize

Any ideas what could cause this?

Could it be that the current heats things up and it takes a while for everything to stabilize ?

I looked at it using http://api.thingspea...ls/637/charts/2 and it looks relatively stable ... have you tried to see the average over a couple of readings to eliminate the jitter ?

Are you powering via USB? I believe it works fine when using external power supply other than USB. I am unsure if this is an issue with certain USB ports or all.

Indeed, it was stable when powered by an external 9V

I posted firmware builds of my math library to the forums. There seemed to be a huge lack of interest so I did not pursue it any further.

That was before I got a netduino It would be useful to have one ...

At home I have a ready-to-use basis for Netduino Plus (SD+ETH needed) and Silverlight on PC.
The SL page polls the N+ every sec asking for data. The N+ web-server answers back to the page, finally the data is both graphically and tabled.
Is that what you are looking for?

I don't have a netduino plus yet nor do I have a ethernet shield but yes, this is exactly what I'm looking for as a frame for this mathematical tutorial ! That would be a great start ! I could probably do the missing code even without ethernet connection (using debug.print lol).

YES ME WANT Please !

Put it in a new project showcase and I'll grab it from there ! Or in the wiki ? Your choice !

Boy do I love this community !

But why do you thinking to a web server?

To show the results on a PC ... live !

And the timestamp would mark the begining and end of the call on the netduino to the math function (for the netduino values).

The webserver would receive a function to test and a series of values to use. For each value to test the function with, a timestamp is used to calculate the number of ticks needed to execute it (some input values might take longer to calculate the output than others). It would reply with a table of data to display on the PC side by side the PC calculated equivalent sent to the netduino to compare

We could even show the values graphically (I do need to learn how to do that too, lol)

Michel, I really can't understand what you are going to propose and for what target...

I propose to build a tutorial that would have a good side effect : show the differences between the math libraries on the netduino and the ones on the PC.

It would do many simple things :

1- show how to create a web server on the netduino (a sample already exist so we can use that)
2- show how to interact with that web server from a pc (the sample does already show that)
3- show the simplest form of table data display on the pc (i need to learn how to do that)
4- show how to timestamp data results to get processing time on the netduino and on the pc (I also need to learn that)
5- show what math functions are available on the netduino and
6- show the induced errors of those functions in certain input value ranges (needed when doing complex mathematical algorithm) on the netduino
7- show the time cost of using certain mathematical functions with certain input value ranges

Anyone interested in using the complex mathematical functions on the netduino should be made aware of the induced errors with certain input ranges of some functions and the time cost of using those functions in their netduino application.

That is the goal I want to attain. Inform of the errors and cost of each mathematical functions available on the netduino, and teach a thing or two while doing it (like tabular data display on the PC) !