B4R Tutorial Controlling DSTV decoder from Android device via Nano and HC-05 bluetooth module

rabbitBUSH · Dec 26, 2020

Dear @Johan Schoeman

Thanks for your contributions, some of which have assisted me greatly.

Having NOTHING like the experience and skill you have at this sort of programming, and, having seen your multiple IF..Then..Else IF..then statement, I wondered if there is a technical reason why the following would not work? Assuming, of course, I have understood Buffer and for loop purpose. [[and also have this code correct]]

Select Case attempt:

For i = 0 To Buffer.Length - 2 Step 2
    Select (Buffer (i + 1))
        case 1
                program = 1   
        case 2
                program = 2
        .
        .
        case 39
                program = 39
    End Select

    detail
next

Johan Schoeman · Dec 27, 2020

rabbitBUSH said:
Dear @Johan Schoeman

"......having seen your multiple IF..Then..Else IF..then statement, I wondered if there is a technical reason why the following would not work? Assuming, of course, I have understood Buffer and for loop purpose. [[and also have this code correct]]..."

Select Case attempt:

For i = 0 To Buffer.Length - 2 Step 2 Select (Buffer (i + 1)) case 1 program = 1 case 2 program = 2 . . case 39 program = 39 End Select detail next

Using the Select statement vs If..Then...Else...in my sample code in post #1 increases the usage of the program storage space from 18 104 bytes to 21 208 bytes. It is 3 104 bytes more = 10.1% more of the available program storage space which on the Nano is limited to 30 720 bytes. But using the Select statement in your proposal above does work at the expense of using more of the available RAM

See the post here:

if elseif vs. switch

I got the impression that if else if chains seem to often produce smaller code then switch statements. Has anyone an explanation why this is the case? I as somewhat curious. I would have expected that switch statements produce shorter code. Why is it the other way round? Udo

forum.arduino.cc

rabbitBUSH · Dec 27, 2020

That's a bit surprising and interesting. I remember being told SELECT /in other languages/ is more efficient, and certainly more readable. Its also supposed to take out the mission of getting those if .. then.. elseif.. sequences logically correct. //big thing in excel this//.

Seems there are a few things arduino Have to work out. Printf is one that may have been corrected. Since C seems to be well associated with arduino, and Select in C is supposed to be more code efficient...one would think......

Will look at the link In due course...it will be relevant in a current project.

Thanks.....

Johan Schoeman · Dec 27, 2020

rabbitBUSH said:
That's a bit surprising and interesting. I remember being told SELECT /in other languages/ is more efficient, and certainly more readable. Its also supposed to take out the mission of getting those if .. then.. elseif.. sequences logically correct. //big thing in excel this//.

Seems there are a few things arduino Have to work out. Printf is one that may have been corrected. Since C seems to be well associated with arduino, and Select in C is supposed to be more code efficient...one would think......

Will look at the link In due course...it will be relevant in a current project.

Thanks.....

I try to steer clear of using nested IF's in Excel and rather use Array Formulas - in MHO one of the best and most powerful features in Excel.

rabbitBUSH · Dec 27, 2020

Hehe hehe I steer clear of excel if I Can....
The link was interesting conversation and back in 2010 nog al. Have seen other threads suggesting arduino is slow to respond on some stuff.

Remember DSTV gets nasty when something comes along to challenge their monopoly grip /just like trump/

Stay safe in Durbs.

hatzisn · Dec 30, 2020

Johan Schoeman said:
Just for the fun of it. Can now control my Digital Satellite TV decoder from anywhere in my house....
............

View attachment 104944

Just out of curiosity what is the maximum distance the IR led works to send the IR codes to the receiver? And further more what is the correct way to choose a led that will work from a higher distance let's say 8-10 meters?

Johan Schoeman · Dec 31, 2020

In my usage case the little breadboard with the circuit is standing at the decoder due to the distance limitation of the IR LED. But I connect the the HC-05 via Bluetooth via the mobile device from anywhere in the house and therfore don't rely on the distance of the IR LED.

Daestrum · Feb 10, 2021

As you check values between 1 and 39 in your if statements could you not just use

B4X:

...
If buffer(i + 1)> 0  And buffer(i + 1) < 40 then ' values 1 to 39
      program = buffer(i + 1)
      detail
End If
...

(that should save some bytes)

Firdoshnd · Apr 17, 2021

Hi Johan , Thanks for all your great projects, I am trying to make a remote bender/extender using an Arduino Nano with IR receiver & IR Tx module, to control an Explorer decoder which is in a closed cupboard. May you guide me on how to set up the hardware do I need two Arduino's one for receiver and one for TX? I have gone thru many videos on you tube but non show using existing remote to relay the IR signal. The project above is great but I do not want to use a cell phone. Your guidance would be greatly appreciated and prepared to pay you a fee up front for this. Thanks..

B4R Tutorial Controlling DSTV decoder from Android device via Nano and HC-05 bluetooth module

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