cross6

You're right, I didn't stop to consider the pull-up resistor.

In that case, a schmitt-trigger or 'master-enable' method as mentioned earlier using gates.

A pulldown is not a good solution, as Mario has explained. I don't know why this keeps getting suggested. What you're having effectively then is

o 3v3
  |      
 .-.     
 | |     
 | | 15k 
 '-'     
  |      
  o-----o GPIO
  |      
 .-.     
 | |     
 | | 2k2  
 '-'     
  |      
  o GND

(if i remember the pullup value correctly) which will mean that you read about 0.42V at boot, which might not be logic low for everything. Also, in this setup, you waste ~1.5mA when you want to drive the pin high later ...

Hi cross6,

The .NET is a full .NET IL interpreter. It includes a .NET runtime, garbage collection, threading, hardware abstraction, etc. It is a lot to fit on an MCU; it's pretty cool

The code that you're running on the Netduino is compact MSIL, interpreted at runtime by .NET MF.

Chris

Very cool! Thanks.

It happens automatically. C# uses garbage collection to clean up resources when memory gets low.

If an object has a Dispose method, you can call it to mark it for cleanup. Also, Debug.GC(true) will clean up any free-able memory.

Chris

Does the netduino actually run the .net runtime and do things like garbage collection? That seems like a lot to fit on the mcu, I assumed it just boiled down the .net CIL to the board's mcu?

Floating point can be emulated with predefined logarithm, antilog, and sin tables. Would that be a more compact solution? (Or is that what it's already doing?)

A 2.2K pulldown resistor wil solve this issue.