B4R Question Wrapping Library for BMP180 sensor

[rwblinn]

Hi,

still struggling how to wrap an Arduino Library. So many variations around ... means would be great (just) to import in B4R without wrapping.

One of the B4R HowTo Experiments working upon, is a mini weather station.
Temperature + Humidity
The DHT11 sensor is now working fine (with wrapped library rDHT11 based on DHT11 lib).

Airpressure
Next is the BMP180 sensor with library SFE_BMP180 to be wrapped as rBMP180.
... but (again) got stuck in how to wrap a base type SFE_BMP180 as defined in the SFE_BMP180.h.
The methods like begin() etc. seems straight forward to convert.

class SFE_BMP180
{
    public:
        SFE_BMP180(); // base type
    char begin();
       // call pressure.begin() to initialize BMP180 before use
       // returns 1 if success, 0 if failure (bad component or I2C bus shorted?)

Any help appreciated.

 

[Erel]

It is a constructor with no arguments. You don't need to wrap it.

 

[rwblinn]

Thanks a lot - Gave a try BUT got stuck after a day puzzling :-(.

Any hints really appreciated.

 

[Erel]

It was not a simple library to wrap. Please try version 1.00.

Sub Process_Globals
   Public Serial1 As Serial
   Private sfe As SFE_BMP180
End Sub

Private Sub AppStart
   Serial1.Initialize(115200)
   Log("AppStart")
   Log("Initialize: ", sfe.Initialize)
   If sfe.GetTemperature Then
     Log("Temperature: ", sfe.LastResult)
   End If
End Sub

 

[rwblinn]

Thanks a lot - this is really great - will revert back by cob tomorrow.

 

[rwblinn]

Hi,

confirmed working fine - again many thanks for fantastic support = will write up a B4R BMP180 tutorial.

Sub Process_Globals
    Public Serial1 As Serial
    Private bmp180 As SFE_BMP180
    Private Temperature, Pressure, PressureSeaLevel, Altitude As Double
    Private ALTITUDEHAMBURG As Double = 27.0    'in meters
    Private Timer1 As Timer
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    bmp180.Initialize
    Timer1.Initialize("Timer1_Tick", 2000)
    Timer1.Enabled = True
End Sub

Private Sub Timer1_Tick
    If Not(bmp180.GetTemperature) Then
        Log("Error retrieving the temperature.")
        Return
    End If
    Temperature = bmp180.LastResult
    bmp180.GetPressure(0, Temperature)
    Pressure = bmp180.LastResult
    Log("Pressure [mBar]:", Pressure)
    PressureSeaLevel = bmp180.Sealevel(Pressure, ALTITUDEHAMBURG)
    Log("PressureSeaLevel [mBar]:",PressureSeaLevel)   
    Altitude = bmp180.Altitude(Pressure, PressureSeaLevel)
    Log("Altitude [m]:", Altitude)
    Log("---")
End Sub

with output

AppStart
Temperature [C]:22.6287
Pressure [mBar]:1017.1806
PressureSeaLevel [mBar]:1020.4424
Altitude [m]:27.0014
---
Temperature [C]:22.6045
Pressure [mBar]:1017.1388
PressureSeaLevel [mBar]:1020.4004
Altitude [m]:27.0014
---

 

[monki]

Hello,
I have a problem with the SFE_BMP180 libary.
it works fine on a uno board, on a Wemos d1 Board it delivers wrong values.
Is there a solution ?

monki

 

[Erel]

Which pins are you using?

 

[monki]

I Use Pin D1,D2

 

[Erel]

I've ordered a sensor. It will take several weeks for it to arrive. I will then check it...

 

[monki]

Many Thanks,
How can I Donate for your super Service?

Monki

 

[Erel]

How can I Donate for your super Service?

No need. The way to help is to spread the word about B4R and the other tools

 

[william235]

I Use Pin D1,D2

What kind of values are you getting? I am reading 115 degrees and 1452 millibars
I have changed sensor and I have changed wemos board. both give the same wrong answers

 

[monki]

I have the same wrong values

Monki

 

[Erel]

This issue is fixed in v1.10: https://www.b4x.com/android/forum/threads/bmp180-pressure-and-temperature.67730