Simon B

Guys,

Here's a wild idea...

We can see that the .Net MF has an ARM JITter. I wonder if one can use this code as a basis for a custom IL -> native compiler. What are the licensing implications? How hard would it be? Is it just too crazy to work?

It could even be converted to a C# tool that can be run as a post-build step that takes as input a managed DLL and produce a native ARM file.

Or something along those lines...

Am I a lot more stupid than I thought, or does the above post indicate that in the next release (4.2) of the .NET Micro Framework, the TinyCLR will include a JIT compiler targeting ARM processors?

Doesn't that solve everyone's problem with IL v's Native Code? If the CLR embedded on the device is able to JIT Compile to ARM native instructions, we should get within 10% of the speed of executing native code anyway (after a brief delay loading the code)?

AOT compilation of the code would be better than JIT, but it all results in native (not interpreted) instruction handling... surely?

or am I insane?

Hi, Responding to the original post: There are a number of (more expensive) IMU boards/sensors that combine magnetic field sensors, a three-axis accelerometer and a three-axis gyro, and sometimes a GPS to produce a tilt-compensated velocity, angle and direction reading. These are specifically designed to be used for aircraft/drone control systems. They are often called "Six Degrees of Freedom" or "Nine Degrees of Freedom" sensors, and can be used as an AHRS (Attitude Heading Reference System). They can cost up to and over $100 though, which is quite expensive for a single board...you wouldn't want it to crash too many times :-) Check out this spark-fun product for $89: http://www.sparkfun.com/products/10724 Also, this sparkfun category: lots of boards that do exactly what you want: http://www.sparkfun.com/categories/160 Also, you might want to consider combining the IMU with thermopile sensors to work out the horizon line (and therefore the AOA), Thermopile sensors are a sort of calibrated infra-red camera. The sort of thing that is used in those new, instant in-ear thermometers: it 'sees' the temperature of an object by measuring the wavelength and intensity of the infra-red light it emits. These are typically used by drones to align themselves with the horizon by detecting the temperature difference between the ground and the sky, and have been used on an open-source Arduino based autopilot system called Ardupilot: http://diydrones.com...pilot-main-page Hope this helps. Cheers, Simon.

Hi Mario, Thanks for the reply. I had hoped that creating an EC meter would be reasonably simple, but from your post I may just buy one... which adds to the final build cost of the product :-( I will stress though that I am not attempting to calculate PH...that requires very specialized probes that have a special type of glass with particular insulating/gas permeability properties. Also the reading doesn't need to be exact, really it just needs to be a relative indication. If we can assume that the first solution to go in is correct, the system just needs to know if and how much the EC has changed, and then deliver extra water or nutrients until the reading returns to its initial value. ...By the way, the circuit I was struggling to think of, that would create AC from two micro-controller GPIO pins: "I have a vague idea it could be achieved with diodes and two pins off the netduino (one for positive, one for negative) like a backwards bridge rectifier, but I can't quite work it out." Turns out, this is an actual circuit called a "H-bridge" and is used often in DC Motor drivers. I have been able to adapt a simple H-bridge design to create a circuit that will generate a varying DC voltage across a pin that is directly proportional to the resistance between two probes that have an AC current moving between them... as the resistance between the two probes increases, the amount of voltage that is redirected back across the GPIO pin increases. It is basically a motor-driver h-bridge with an extra diode, and a resistor setup as a voltage divider. It definitely works to produce a micro-controller powered inverter, whether it can test EC is another matter. I haven't actually tried to test or calibrate a reading yet... from your post, it probably won't be possible, but I will post back if I get any consistent results.

Hi The output is in the immediate window! (Debug-->Windows-->Immediate) Ctrl+Alt+I I am getting EXACTLY the same issue: Running Netduino (standard) Visual Studio 2010 Pro, Sp1, Windows 7 64 bit edition. Getting exactly the same symptoms: debugger works fine, except that it doesn't seem to be getting the output from the Debug.print commands, I can also see the output in MFDeploy. When I attached to a running process on my netduino using the Visual Studio debugger, I briefly caught output from the program in the debug window, but only a few lines were written. My presumption was that the debugger itself is somehow blocking the messages. It was sheer chance I was looking through the available windows in debug mode, when I noticed the expected program output was appearing in the immediate window! The debugger must route the output to the immediate window (Maybe it is an option in Visual Studio somewhere) Hope this works for you too. Cheers, Simon.