Did you remember the "ancient" PC-XT @ 4.77MHz, with 640K ram???

Hey, I bought a co-processor for one of those to make my galaxy creation simulation work in a week instead of a month

However, there are many friends that don't know how to build even a simple circuit with a 555.

I'll have to learn about those

Secondly, perhaps they are attracted by this board and would build a very simple application.

Yeap, that is me, simply learning .net in an interesting way (.net in all forms, normal, phone and MF, cool and having fun)

Thirdly, such a context is very useful because it shows clearly some lacks of a Netduino/MF board.

This is the goal of this experiment. Find out what works and what is missing, all for the ease of programming whatever we get our hands on

I'm looking at a 3D Printer right now and it is because I played with a netduino that I might have on in a few months

It is not a problem of our lack of knowledge about what to use when ... it is a question of finding out how we can adapt our tools to help even more

I Love This Community (ILTC)

Hesitating between these two : Saleae or DSO 2090 USB PC USB Oscilloscope 40MHz 100MSa/s 2CH Picoscope are way out of my budget (which is between 150 and 250, tax and shipping included)

using System; ActualReading = Convert.ToUInt16(sActualReading);

It got me thinking ... We should have an application that is PC based, that talks to a netduino through IP. The PC version would display the difference (3 columns, one for the selected function PC result, one for the Netduino result and one for the differences) for input many values for a selected function (have a combobox with all the available function) (2 more columns for the time it took ?) The PC application would poll the netduino for a series of results from a given function and a given series of input values, and then display them on screen. This would allow to show the valid ranges of some functions (we do that in physics) and the cost of using them (FFT you need something fast no ?). It would also allow the library coders see the results of their implementation on the spot Web server on the netduino plus, PC app that talks to the netduino server showing columns (I need to learn how to do all that lol) It would be a great application for anyone that wants to use the netduino for science ... they would know right there and then what would be the cost and errors induced by using the netduino. I vote for this as a tutorial Anyone interested ?

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)

I will have to see if I can get a build cooked up for you. Which Netduino do you have?

Normal Netduino for me ! Will need the Netduino plus to test it live with the webserver app that Mario put on the forums that I need to modify for this purpose (Thanks Mario)

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) !

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 !

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 ...

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

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 !

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

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 ?

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 !

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 !

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

Just leaving a breadcrum to remember Thanks Omar !

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

.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

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.

Man, Great Job ! And that was in December ! Do you have plans to show the code ? or we can only drool ? Has Chris Seto seen this ? He was saying impossible ! So good job !