zorlack

Yeah I pretty much immediately found this. Fail.

Hehe.

Thanks for this tip Paul!

To get the most out of your LED, you will want to supply it from the 5V rail, with a series resistor.

If you use the 3.3V rail, you will not be giving it the full 3.3 due to a small voltage drop accross the transistor.

If I connect the transistor to +5v, do I not have to have +5V to trigger it as well?

-Z

Thanks NooM!

Will using a transistor in that fashion pass the PWM pulses along to the LED, or will it lock to high or low?

i power all my stuff external.

NooM, forgive my ignorance, but does that mean you have one PS which powers the Netduino, and another which powers your sensors? Does that mean you have two connections to Mains, or are are you using two sets of batteries?

Regarding the capacitor: Is it simply a matter of putting the capacitor between +3.3 and the Power Input of the TMP36? Is that simply to smooth out the voltage, in-case of minor dips?

Thanks so much!

-Z

The analog values were off significantly. (The temperature here is about 20C I was getting readings as high as 40C, and my average readings were about 6C high)

Eventually I started using the TMP36 object in the NETMF toolbox, but originally I was trying to do it myself. What I saw was that when I did an AnalogInput.ReadRaw() sometimes I was getting values significantly higher than 1023. I presumed that this was related to the bitwise precision of the AnalogInput object so I tried instantiating it with: 

AnalogInput input = new AnalogInput(AnalogChannels.ANALOG_PIN_A1, 10);

But this caused it to throw an Invalid Argument Exception. I'm not sure if that's necessary or not. (The documentation for the AnalogInput constructor is a bit borked)

I checked bus voltage, and with and with-out the LCD I was reading exactly 3.30v.

• Can I connect things to the 3.3V header while the microcontroller is running?
• Would I be better off powering the LCD using the 5V header and voltage dividing resistors?

As for the LCD, it's being driven by the NETMF SerialPort object. Which I presume is just a 9600bps serial port transmitting out GPIO1.

Thanks so much for your help!

-Z