Leyendo el sensor ultrasónico HC-SR04 con Gadgeteer y Visual Basic
Este programa pretende ser un punto de partida para la lectura del sensor HC-SR04, pero por supuesto usted debe proporcionar las funciones Adicionales necesarias, tales como «tomar valores promediados« para obtener un mínimo de precisión 🙂
Imports GT = Gadgeteer
Imports GTM = Gadgeteer.Modules
Imports GTI = Gadgeteer.Interfaces
' This program is intended as a starting point reading the HC-SR04 sensor,
' but of course you must provide adicional functions like "take values from average" to make a minimum of precission.
Namespace GadgeteerApp1
Partial Public Class Program
'Define GPIO's
Private Echo As GTI.DigitalInput
Private Trig As GTI.DigitalOutput
Private Ticks As Integer = CInt(TimeSpan.TicksPerMillisecond / 1000)
'Define socket number
Private soketNum As Integer = 9
'Main
Public Sub ProgramStarted()
Dim socket = Gadgeteer.Socket.GetSocket(soketNum, True, Nothing, Nothing)
Echo = New GTI.DigitalInput(socket, Gadgeteer.Socket.Pin.Three, GTI.GlitchFilterMode.Off, GTI.ResistorMode.PullDown, Nothing)
Trig = New GTI.DigitalOutput(socket, Gadgeteer.Socket.Pin.Four, False, Nothing)
timer.Start()
Debug.Print("Program Started")
End Sub
' Just print distance into Debug windows
Private WithEvents timer As GT.Timer = New GT.Timer(1000)
Private Sub timer_Tick(timer As Gadgeteer.Timer) Handles timer.Tick
'
Debug.Print(readSR04.ToString())
End Sub
'Define Max/Min for SR04 reading distances
Private Const Dist_MIN As Integer = 2 'cm
Private Const Dist_MAX As Integer = 400 'cm
'Define return values if reading fails (out of range)
Private Const Flag_MIN As Integer = -999
Private Const Flag_MAX As Integer = 999
'This function returns distance in cm from SR04
Function readSR04() As Integer
Dim start As Double = 0
Dim Distance As Integer = 0
Dim Fails As Integer = 0
'send a 10us TTL pulse
Trig.Write(True)
Thread.Sleep(10)
Trig.Write(False)
'wait for the echoe
While Not Echo.Read
Fails += 1
If Fails > 500 Then
Thread.Sleep(0)
Exit While
End If
start = System.DateTime.Now.Ticks
End While
' calculating distance
While Echo.Read
Thread.Sleep(0)
Distance = CInt(((System.DateTime.Now.Ticks - start) / Ticks) / 58) + Dist_MIN
End While
If Distance < Dist_MAX Then
If Distance >= Dist_MIN Then
Return Distance
Else
Return Flag_MIN
End If
Else
Return Flag_MAX
End If
End Function
End Class
End Namespace
Saludos,
PepLluis,