oTone Object

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Description
Operation
Properties

Examples
Connections
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Version History & Bug list

Description:

The oTone Object is a Hardware Object that generates and outputs a low frequency tone.

It is capable of generating a frequency output between 8.9Hz and 1,132Hz.

The following table lists the size and availability of the oTone Object.

	Object	Size	Description	A1	A2	B1	B2	C1
	oTone	5 Bytes	An Object that outputs a tone.			x	x	x

Operation:

When the Operate property is 1, the oTone Object cycles the I/O line specified by the IOLine property at a rate specified by the Tone property thereby producing a tone output that can drive a speaker.

The Tone property specifies the frequency of the tone. The frequency is derived from a 1,132kHz clock divided by 128 minus the value of the Tone property. [1132/(128-Value)] For example, a value of 120 will produce a 141.5Hz Tone. [(1132/(128-120)) = 141.5] If 0 is given as the Tone, then the output is shut off. This is useful for some rudimentary low frequency tones. If you need a higher frequency, see the oSpeaker object. if you want music, see the oSoundgin object.

The lowest frequency that can be generated is 8.913Hz [(1132/(128-1)) = 8.913]
The highest frequency that can be generated is 1132Hz [(1132/(128-127)) = 1132]

Note that the frequencies are not linear. This will be most noticeable at the higher frequencies.
(1132/1=1132Hz, 1132/2=566hz).

Two or more oTone Objects can be set to use the same I/O line. When this is done, the cycles of the multiple tones are combined.

The oTone Object's output shares its timing with the rest of the ooPIC's multitasking objects. A large number of Objects running concurrently with the oTone Object can result in distortions on the higher frequency tones.

The Freq property is an instance of the oFreqL Object which is created when the oTone object is. The oTone Object uses the oFreqL Object to create the actual tone output. Attributes of the tone can be adjusted by directly manipulating the oFreqL Object. (see oFreqL Object for more detail)

Properties:

The following table lists the properties of the oTone Object:

Property
Description

Tone

A value that specifies the tone to output.

Object Class: oByte Value Range: 0 - 127 (MSB of byte not used)

Data Type: Numeric Default Value: 0

Determines the tone using the following formula: frequency = 1132/(128-Divisor)

Operate Description

0 The tone is disabled.

1 The tone is generated at 8.913Hz.

2 The tone is generated at 8.984Hz.

3-125 The tone is generated at the specified frequency.

126 The tone is generated at 566Hz.

127 The tone is generated at 1132Hz.

IOLine

A value that specifies which I/O Line to use to output the tone.

Object Class: oIOLine Value Range: 0 - 31

Data Type: Numeric Default Value: 0

Some I/O Lines have special purposes. Be sure to see oIOLine help file for details.

Operate

A value that selects whether or not the tone is outputted.

Object Class: oOperate Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Operate Constant Description

0 cvOff The tone is not generated.

1 cvOn The tone is generated.

Freq

The I/O function object used to output the tone.

Object Class: oFreqL Value Range: 0 - 127

Data Type: Numeric Default Value: 0

Address

Returns a pointer to the address of the oCounter Object instance.

Object Class: oAddress Value Range: 0 - 127

Data Type: Pointer (Read Only) Default Value: Address of Object

Examples:

In the following example, the oTone Object is used.

Visual Basic Syntax

C and Java Syntax

' Produce an alarm every 
'  two seconds.

Dim T As New oTone

Sub Main()
  T.IOLine = 21
  Do
    Call Alarm
    ooPIC.Delay = 2000
  Loop
End Sub

Sub Alarm()
  T.Operate = 1    
  Do 5 Times
    T.Value = 120
    ooPIC.Delay = 30
    T.Value = 117
    ooPIC.Delay = 30
  Loop
  T.Operate = 0
End Sub

// Produce an alarm every
// two seconds.

oTone T = New oTone;

Void Main(Void){
  T.IOLine = 21;
  Do{
Call    Alarm;
    ooPIC.Delay = 2000;
  } While (1);
}

Void Alarm(Void){ Byte x = 0;
  T.Operate = 1;
  Do{ x++
    T.Value = 120;
    ooPIC.Delay = 30;
    T.Value = 117;
    ooPIC.Delay = 30;
  } While (x<5);
  T.Operate = 0;
}

Basic Syntax

' Produce an alarm every 
'  two seconds.

Dim T As New oTone(21)

Do
  Call Alarm
  Delay = 2000
Loop

Sub Alarm()
  T.Operate.TurnOn
  Do 5 Times
    T.Value = 120
    ooPIC.Delay = 30
    T.Value = 117
    ooPIC.Delay = 30
  Loop
  T.Operate.TurnOff
End Sub

' Combine 2 tones

Dim T As New oTone
Dim G As New oTone

Sub Main()
  T.IOLine = 21
  T.Value = 113
  T.Operate = 1
  G.IOLine = 21
  G.Value = 127
  G.Operate = 1
  Do 
    ooPIC.Delay = 150
    G.Operate = 0
    ooPIC.Delay = 150
    G.Operate = 1
    G = G - 1
  Loop
End Sub

Connections:

The oTone Object uses the single I/O line specified by the IOLine property. The output of the I/O line needs to be filtered before it can be connected to a speaker. A simple filter can be constructed with two resistors and two capacitors as shown in the wiring diagram. Note that I/O lines 16 through 23 are used for special purposes. Be sure not to specify any of these I/O lines if these special functions are in use.

Caution: Do NOT connect the outputs of the ooPIC directly to a speaker. The TTL circuitry of the ooPIC is not designed to drive the power requirements of a speaker. Doing so can potentially damage the ooPIC's TTL outputs.

If volume control is needed, an amplified circuit can be used. The LM386 is a commonly used operational amplifier. Shown in the following schematic, it is used to amplify the audio signal after it has gone through the filter circuit.