2 replies to this topic

[Bernie]

Does the Netduino have the facilities to read PWM? If so, can anyone point me to some documentation on how or an example?

 

Thanks,

Bernie

 

[jrlyman3]

Bernie,

 

The Netduino is not really fast enough to do this sort of thing in managed (C#) code.  And it's difficult to add unmanaged libraries and solve the problem that way.  In my opinion you have two choices:

 

1. The following fourm talks about a library for interfacing to the DHT-11 device which uses pulse width encoding of its digital data.  http://forums.netdui...managed-driver/ it uses interrupts to detect the edge of each pulse and compute the pulse width from the timestamp that comes with each interrupt.
2. Use an Arduino (there is probably code already out there) and interface it to the Netduino with rs-232, I2C, or SPI.

I'm working on the Arduino solution for interfacing some hardware to the Netduino right now.

 

John

[Bernie]

Thanks for the reply John. I suspected then Netduino wouldn't be fast enough. I was hoping there may be some direct to CPU method, maybe using the I2C interface. Right now we are doing proof of concept so the Netduino's threading ability makes the code much easier to develop, but the interface to hardware much more difficult, hahaha. The device is a US Digitial MA3 absolute shaft encoder that needs micro second timing of pulses. To a raw processor that's fine, but to managed code that's very very very small.

 

I'm working on a hardware solution with a timer, a counter, and a latch to maybe make a readable solution.

 

Thanks,

Bernie