Seeedstudio wrong values

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21

But, he’s using the regular Analog I/O from NetMF. I think the Seeed Gadgeteer code could just confuse things as Gadgeteer uses a 0.0 to 1.0 and NetMF uses an int value of (as far as I know) unspecified range.

…or I completely missed something, which is entirely possible :slight_smile:

As an aside, I just checked the specs on the LPC2387 (which the old white Panda I uses). The chip uses a 10 bit ADC and as such, should (assuming no other code scaling this value in NETMF), returns values between 0 and 1023. That would mean something above, say, 600 or 700 would be pretty wet. :slight_smile:

Pete

22

Thank You,
Ok how would I do code to check if the sensor is connected? Also the sensor that I am using uses a propieretary “grove” connection. There are 4 wires
1.SIG
2.Nothing
3.VCC
4.GND
Would I need the second wire?
Thank You

23

It’d be pretty hard to check to see if it’s connected, as the sensor is simply an open circuit when there’s no moisture.

Is there really going to be a situation where you wouldn’t have the sensor connected while the program was running?

As to the wires:
1 Goes to your analog input pin on the panda
3 Goes to +3.3v on the panda
4 Goes to ground on the panda

You may also need to connect the AREF pin on the Panda to +3.3v (I forget if that’s required on the Panda or if it defaults to +3.3v)

Pete

24

Thank You,

25

Not much of a electric guy but do I need to connect a resistor?
Thank You

26

no need for resistors. The sensor should be stand-alone in that respect.