B4R Code Snippet Oscillator 1-1,000,000 Hz

Using 16b TIMER 1 and inline C to get oscillating output at PIN 9 (Arduino Uno). the frequency can be set to 1Hz up to 1MHz, the output is set by division of the 16MHz crystal.
When the frequency is power of 2 the output is accurate, otherwise the error can be up to 0.04%.

Sub Process_Globals
    Public Serial1 As Serial
    Private frequency As ULong
    Public divide As UInt
    Public prescale As Byte
    Private out As Pin
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    
    frequency=500    'enter requency 1Hz to 1MHz
    
    If frequency>1000 Then
        prescale=0x1A    '0b11010
        divide=1000000/frequency-1
        Else
            prescale=0x1C    '0b11100
            divide=31250/frequency-1
    End If
    RunNative("osc", Null)
    out.Initialize(9, out.MODE_OUTPUT)    '11
End Sub


#if C
void osc (B4R::Object* o) {
      //  set timer1
    TCCR1A = 0b1000011; 
    TCCR1B = b4r_main::_prescale;
    OCR1A = b4r_main::_divide;
}
#End if