Pulse sensor coding for Netduino Plus 2 gone wrong - visual-studio-2010

Question

I'm currently doing a project on Netduino Plus 2 using .net micro framework which requires me to code for a pulse sensor. I have tried finding codes for pulse sensor but to no avail. I tried using AnalogInput codes for pulse sensor but the output values seemed wrong (there was a constant high value despite no heartbeat placed near the sensor). Please advise!
Here are my current codes for the heartbeat sensor:
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
namespace heartrate
{
public class Program
{
public static void Main()
{
SecretLabs.NETMF.Hardware.AnalogInput rate =
new SecretLabs.NETMF.Hardware.AnalogInput(Pins.GPIO_PIN_A0);
int sensorvalue = 0;
while (true)
{
sensorvalue = rate.Read();
Debug.Print("" + sensorvalue);
Thread.Sleep(1000);
}
}
}
}
Here are the specs of the sensor, how it looks like and how it is connected.
http://www.elecrow.com/wiki/index.php?title=Pulse_Sensor
(This tutorial is for arduino, but I think the wiring is similar to that of Netduino)

Answer 1

Hard to tell without specs on your pulse device and how it is attached. For Analog input & output in my latest project (https://github.com/osstekz/cncBuddy) I use classes InputPort & OutputPort (Microsoft.SPOT.Hardware)
ex:
public NESControllerAdapter(Cpu.Pin pinClk, Cpu.Pin pinLatch, Cpu.Pin pinData1/*, Cpu.Pin pinData2 = Cpu.Pin.GPIO_NONE*/) {
// Binds to all pins
this._outpClk = new OutputPort(pinClk, false);
this._outpLatch = new OutputPort(pinLatch, false);
this._inpData1 = new InputPort(pinData1, false, Port.ResistorMode.Disabled);
//if (pinData2 != Cpu.Pin.GPIO_NONE) this._inpData2 = new InputPort(pinData2, false, Port.ResistorMode.Disabled);
}
...then like your rate.Read(); loop
public int ButtonPressed() {
// Locks all parms
this._PinTick(this._outpLatch);
// Reads plug state value
for (int i = 0; i < CncBuddyShared.iTOTALNESCONTROLLERBUTTONS; ++i) {
// Read the value, if true return this index as the first pressed button
if (this._inpData1.Read() == false) return i;
// Selects the next value
this._PinTick(this._outpClk);
}
return NESCONTROLLER_PRESSEDBUTTOM_NONE;
}